orthodontics vol 12 no 1 romano

ORTHODONTICSORTHODONTICSORTHODONTICSVolume 12 • Number 1

ORTHODONTICSORTHODONTICSORTHODONTICSThe Art and Pra� ice of DentofacialentofacialEnhancement

Formerly World Journal of Orthodontics

Manual of Wire Bending TechniquesEiichiro Nakajima

The authors of this step-by-step manual detail the essential components and techniques of customized wire bending, including the fi rst-, second-, third-, and fourth-order bends; selection and proper manip-ulation of pliers; and optimal methods of adjustment to be used during orthodontic treatment.

96 pp (spiral binding); 288 illus (117 color); ISBN 978-0-86715-495-5 (B4955); US $85

Biomechanics in Orthodontics: Principles and PracticeRam S. Nanda and Yahya Tosun

Correct application of the principles of biomechanics leads to highly effi cient orthodontic treatment. This book introduces students of orthodontics to the evo-lution of orthodontic technology and the properties of orthodontic materials and outlines the essential mechanical principles behind successful orthodontic treatment.

168 pp; 350 illus (two-color);ISBN 978-0-86715-505-1 (B5051); US $98

Lingual Orthodontics: A New Approach Using STb Light Lingual System and Lingual Straight Wire

Giuseppe Scuzzo and Kyoto Takemoto

The authors detail the latest improvements in the STb light lingual system, such as improved patient comfort, increased predictability of results, short-ened treatment times, and decreased laboratory work. The biomechanical benefi ts of the STb system are also explained in full, including comprehensive chapters on extractive and nonextractive mechanics, absolute anchorage control, low frictional force, and the lingual straight-wire method.

264 pp; 885 illus (mostly color); 978-1-85097-192-4 (B8846); US $230

Eiichiro Nakajima

Manual of

TechniquesWire Bending

Biomechanics

PRINCIPLES AND PRACTICEIN

OrthodonticsOrthodonticsOrthodontics

Biomechanics

PRINCIPLES AND PRACTICEIN

Orthodontics

CALL: (800) 621-0387 (toll free within US & Canada) • (630) 736-3600 (elsewhere)FAX: (630) 736-3633 • EMAIL: [email protected] • WEB: www.quintpub.comQUINTESSENCE PUBLISHING CO INC, 4350 Chandler Drive, Hanover Park, IL 60133 04/11

TO ORDER

Pediatric Laser Dentistry: A User’s Guide

Giovanni Olivi, Fred A. Margolis, and Maria Daniela Genovese

Lingual and Esthetic OrthodonticsEdited by Rafi Romano

Quintessence

Invisalign Orthodontic TreatmentRichard Bouchez

Esthetics, Growth, and Orthopedics of the Face: Facial Development and Transformation in the Eye of the Orthodontist and Other Beholders

Joseph G. Ghafari

Available Winter 2012

Handbook of Cephalometric SuperimpositionHerman S. Duterloo and Pierre-Georges Planché

The Alexander Discipline, Volume 2: Building Facial Harmony and Stability

R. G. “Wick” Alexander

NEW TITLES FROM

74

52

ORTHODONTICSThe Art and Pra�ice ofDentofacial Enhancement

Table of Contents

Editorial 5 The relevance of orthodontic articles

Rafi Romano

Forewords 9 Ronald Goldstein/Michael Cohen

Scientific Innovation10 Modification of the bidimensional system

Daniel J. Rinchuse/Donald J. Rinchuse

22 Posttreatment compliance with removable maxillary retention in a teenage population: A short-term randomized clinical trialMarc Bernard Ackerman/Barry Thornton

Technology28 AUSOM: A 3D placement guide for orthodontic mini-implants

Mahmoud Al-Suleiman/Manal Shehadah

Controversy38 Phantom bite: A survey of US orthodontists

Bozena B. Ligas/Maria Therese S. Galang/Ellen A. BeGole/ Carla A. Evans/Gary D. Klasser/Charles S. Greene

Interdisciplinary48 A multidisciplinary approach to the treatment of a horizontally

impacted mandibular second premolar: 10-year follow-upDror Aizenbud/Liran Levin/Shaul Lin/Eli E. Machtei

Case Reports60 Orthodontic management of an originally surgically planned

treatment of an open bite: A case reportChadi Kassir/Samar Bou Assi

Practice Pearls70 Dental amalgam corrosion in vacuum-formed retainers

Joseph R. Karam/Daniel J. Rinchuse

Treatment Planning Challenge75 Missing maxillary lateral incisors: To close or to open?

Management78 The dentist as a manager: Building effective relationships and

networks for personal and professional advancementHilla Dotan

Vignettes82 Marc Bernard Ackerman

SPRING • 2011 Volume 12 • Number 1

ISSN 2160-2999 (print)ISSN 2160-3006 (online)

52

62

ISSN 2160-2999 (print) • ISSN 2160-3006 (online)

PublisherH. W. Haase

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EDItor-In-ChIEF

rafi romano, DMD, MScPrivate Practice of Orthodontics

Tel Aviv, Israel

ASSoCIAtE EDItor

Marc Bernard Ackerman, DMD, MBADirector of Orthodontics, Children’s Hospital Boston

Boston, Massachusetts, USA

EDItorIAL BoArD

S. Jay Bowman, DMD, MSDPortage, Michigan, USA

Vittorio Cacciafesta, DDS, MSc, PhDMilan, Italy

Pablo Echarri, DDSBarcelona, Spain

Kurt Faltin Jr, DDS, PhDSão Paulo, Brazil

nigel harradine, BDS London, FDS rCSEd, FDS Morth, rSCEng, MScBristol, United Kingdom

John C. Kois, DMD, MSDSeattle, Washington, USA

hee-Moon Kyung, DDS, MS, PhDDaegu, Korea

Stephen rimer, DDSBoca Raton, Florida, USA

Maurice A. Salama, DMDAtlanta, Georgia, USA

David Sarver, DMD, MSBirmingham, Alabama, USA


Formerly World Journal of Orthodontics

Volume 12, Number 1, 2011 5

EditorialThe relevance of orthodontic articles

I n recent years, orthodontic treatment has become extremely common among and accessible to a wide patient base.

In 1997, the World Federation of Orthodontists commissioned a study of its affiliated organizations

for the purpose of gathering information about the global orthodontic com-munity. The countries surveyed covered 54% of the world’s population, ac-counting for nearly 3.3 billion people. The number of orthodontists was 31,000. The highest ratios of orthodontists in relation to population (per 100,000 inhabitants) were found in North America, Central and South America, and Europe (1.4 to 2.6).1

Today, with more than 70 accredited orthodontic postgraduate programs in the United States and Canada, 12 in the United Kingdom, and many more in Asia (in India, for example, about 300 new specialists in orthodontics graduate every year), there is a growing number of faculty members (lecturers and professors) at universities. The academic component for tenure and promotion compels these orthodontists to write articles to be published in Medline-indexed journals, pref-erably those with high impact factors. As a result, thousands of articles are sub-mitted to orthodontic journals each year. Orthodontics receives about five new submissions each week, or approximately 260 articles per year (meaning that only one of every six submitted manuscripts will eventually be published).

Most of the articles are rejected, but many of those that are eventually pub-lished have very little clinical significance. In vitro research with poor statis-tics, clinical studies with minimal sample sizes, and conclusions that are not evidence-based are part of every journal. At the same time, journal subscriber-ship constantly decreases. In addition, the variety of free scientific and clinical information online threatens the profitability of printed journals that are not affiliated with professional societies or study clubs.

Our mission is to find a common denominator that will attract clinicians, researchers, and postgraduate students. We have a commitment to stay relevant, despite today’s tendency for instant messages and 140-character “tweets.” Evidence-based information is the essence of scientific and clini-cal articles. Even in countries where dental awareness is low, there is rising interest in evidence-based dentistry (EBD).2 For EBD to become part of decision making in practice, the most current and comprehensive research findings must be translated into practice.3 We should focus on the take-home message rather than satisfying the deans of faculties who quantify the number of articles published as the essential requirement for academic promotion. Barriers for implementation of research into practice primarily include lack of interest, lack of involvement, lack of time, and lack of re-muneration.4 As stated by David Turpin, the former editor of the American Journal of Orthodontics and Dentofacial Orthopedics, as journal editors, we have the tools and the responsibility to help readers identify the EBD approach in each article.5

Editorial

6 ORTHODONTICS The Art and Practice of Dentofacial Enhancement

Along with my associate editor, Marc Bernard Ackerman, we have divided the journal into 10 different sections, including the most innovative scientific research, daily clinical pearls, updated technology, patient management tips, interdisciplinary case presentations, and treatment planning challenges, where each orthodontist will find tips for more efficient and esthetic treatment results.

Our editorial board members, “The 10,” were carefully selected from all around the world. They have a variety of clinical and scientific backgrounds and are from private and university practices to ensure the relevance of Orthodontics to 21st century demands.

I do hope you will enjoy the new concept and encourage your feedback and submission of relevant articles. Together, we can make this journal an essential clinical tool for the contemporary, evidence-based orthodontist.

Rafi Romano, DMD, MSc Editor-in-Chief

[email protected]

RefeReNCeS

1. Waldman HB, Perlman SP, Schindel R. Update on the imbalanced distribution of orthodontists, 1995–2006. Am J Orthod Dentofacial Orthop 2009;135:704–708.

2. Oladimeji Adeniyi A, Wasiu Lanre A. Evidence-based dentistry in a developing economy—The Nigerian example. Open Dent J 2010;4:51–54.

3. Frantsve-Hawley J, Meyer DM. The evidence-based dentistry champions: A grassroots approach to the implemen-tation of EBD. J Evid Based Dent Pract 2008;8:64–69.

4. Clarkson JE. Getting research into clinical practice—Barriers and solutions. Caries Res 2004;38:321–324.

5. Turpin DL. Consensus builds for evidence- based methods. Am J Orthod Dentofacial Orthop 2004;125:1–2.


Editor-in-ChiEfrafi romano Private Practice of OrthodonticsTel Aviv, Israel

AssoCiAtE EditorMarc Bernard Ackerman

Director of OrthodonticsChildren’s Hospital Boston

Boston, Massachusetts, USA

s. Jay BowmanPrivate PracticePortage, Michigan USA

Vittorio CacciafestaPrivate PracticeMilan, Italy

Pablo EcharriPrivate PracticeBarcelona, Spain

Kurt faltin JrProfessor and ChairDepartment of OrthodonticsUniversity PaulistaSão Paulo, Brazil

nigel harradineConsultant OrthodontistBristol Dental Hospital and SchoolBristol United Kingdom

John C. KoisDirector and FounderKois CenterSeattle, Washington USA

hee-Moon KyungChairDepartment of OrthodonticsKyungpook National UniversityDaegu, Korea

stephen rimerPrivate PracticeBoca Raton, Florida USA

Maurice A. salamaClinical Assistant Professor of PeriodonticsUniversity of Pennsylvania Philadelphia, Pennsylvania Medical College of GeorgiaAugusta, Georgia, USA Private PracticeAtlanta, Georgia, USA

david sarverPrivate PracticeBirmingham, Alabama USA

EditoriAL BoArd “The 10”

Guidelines For Authors

ORTHODONTICS The Art and Practice of Dentofacial Enhancement (ORTHO) will consider for publication original articles on dentofacial enhancement that fall under the following 10 categories:

1. Editorial [Upon request only.]2. Technology [Latest innovation in

technology related to orthodontics. Abstract mandatory.]

3. Controversy [Controversial topics in orthodontics. Pros and cons should be discussed. Abstract mandatory.]

4. Treatment Planning Challenge [Upon request only. No abstract required.]

5. Case Reports [Must include high-quality before and after photographs with full description of treatment sequence. No abstract required.]

6. Scientific Innovations [Scientific updates, research—in vivo and in vitro. Abstract, discussion, and conclusions are mandatory.]

7. Practice Pearls [Tips and tricks for orthodontists’ daily work. Limit 4 pages. No abstract required.]

8. Management [Practice management, marketing, and psychological aspects of orthodontic treatment. Limit 6 pages. Abstract mandatory.]

9. Interdisciplinary Advances [Cases and/or research with interdisciplinary orientation. All disciplines should be well presented in the article. No abstract required.]

10. Vignettes [Stories from the history of orthodontics, appliance invention, etc. Limit 4 pages. No abstract required.]

MANUSCRIPT SUBMISSIONSubmit manuscripts via ORTHO’s online submission service:www.manuscriptmanager.com/orthoFollow the simple step-by-step instructions. As the last step, you will upload your manuscript, which should be a PC Word (doc) file with tables and figures included at the end of the document.

MANUSCRIPT PREPARATION• The journal will follow as much as

possible the recommendations of the International Committee of Medical Journal Editors (Vancouver Group) in regard to preparation of manuscripts and authorship (Uniform requirements for manuscripts submitted to biomedical journals: http://www.icmje.org).

• Manuscripts should be typed in a 12-point font and double-spaced. Pages should be numbered.

• The first page(s) should include the title of the article and the complete names, academic degrees, titles, professional affiliations, full addresses, faxes, and emails of all authors. The corresponding author should be clearly noted; if it is not, the first author will be assumed to be the corresponding author.

• Abstract/key words. Abstracts should include a maximum of 250 words. Abstracts for Scientific Innovations articles must be structured: Purpose, Materials and Methods, Results, and Conclusions. Abstracts for all other types of articles that require one (see description of 10 article categories) need not be structured; these articles should also include up to 6 key words.

• Article text. See page limits for the 10 types of articles.

• Acknowledgments. Persons who have made substantive contributions to the study can be acknowledged at the end of the article. Also specify grant or other financial support, citing the name of the supporting organization and grant number.

• Legends. Figure legends should be typed as group at the end of the manuscript. Detailed legends are encouraged. For photomicrographs, specify original magnification and stain.

• Tables. Each table should be logically organized, typed on a separate page at the end of the manuscript, and numbered consecutively. Table title and footnotes should be typed on the same page as the table.

• Abbreviations. The full term for which an abbreviation stands should precede its first use in the text unless it is a standard unit of measurement.

• Trade names. Generic terms are to be used whenever possible, but trade names and manufacturer name, city, state, and country should be included parenthetically at first mention.

REFERENCES• All references must be cited in the text,

numbered in order of appearance.• The reference list should appear at the

end of the article in numeric sequence.• Do not include unpublished data

or personal communications in the reference list. Cite such references parenthetically in the text and include a date.

• Avoid using abstracts as references.• Provide complete information for each

reference, including names of all authors (up to six). If the reference is to part of a book, also include title of the chapter and names of the book’s editor(s).

Journal reference style:1. Pancherz H, Knapp V, Erbe C, Heis

AM. Divine proportions in attractive and nonattractive faces. World J Orthod 2010;11:27–42.

Book reference style:1. Sarver DM, Ackerman MB. Dynamic

smile visualization and quantification and its impact on orthodontic diagnosis and treatment planning. In: Romano R (ed): The Art of the Smile. Chicago: Quintessence, 2005:99–139.

REVIEW/EDITING PROCESS• Manuscripts will be reviewed by the

editors and reviewers with expertise in the field that encompasses the article.

• Reviews will be completed within 45 days of article submission.

• Original articles are considered for publication on the condition they have not been published or submitted for publication elsewhere.

• Manuscripts that are not prepared in accordance with these guidelines will be returned to the author before review.

• The editor and publisher reserve the right to edit all manuscripts to fit the space available and to ensure conciseness, clarity, and stylistic consistency.

ARTICLE ACCEPTANCEArticle acceptance is pending receipt of images judged to be of sufficient quality for publication (see the guidelines below). Once a manuscript is accepted, authors should submit high-resolution digital image files (on disk) to:

Managing EditorORTHODONTICSQuintessence Publishing Co, Inc4350 Chandler DriveHanover Park, IL 60133

The disk/package should be labeled with the first author’s name, shortened article title, and code number assigned upon acceptance.

DIGITAL IMAGE FORMATWhen preparing final images to send, consider the following points:• Resolution must be at least 300 dpi when

the image is 3 inches wide.• Images saved in TIFF format are

preferred, but JPG or EPS files are acceptable.

• Images grouped together must be saved as individual files.

• Images containing type should either be saved as a layered file or provided along with a second file with type removed.

• Line art (graphs, charts, line drawings) should be provided as vector art (Illustrator or EPS files)

• Please do not embed images into other types of documents (eg, Word, Excel, PowerPoint, etc).

MANDATORY SUBMISSION FORMThe Mandatory Submission Form (accessible at www.quintpub.com) must be signed by all authors and can be uploaded as a separate document with the article submission, or it can be mailed (see address above) or faxed (630-736-3634) to the ORTHO Managing Editor.

PERMISSIONS AND WAIVERS• Permission of author and publisher must

be obtained for the direct use of material (text, photos, drawings) under copyright that does not belong to the author.

• Waivers must be obtained for photographs showing persons.

• Permissions and waivers should be faxed along with the Mandatory Submission Form to the ORTHO Managing Editor (630-736-3634).

REPRINTSReprints can be ordered from the publisher. Authors receive a 40% discount on quantities of 100 or 200.


9Volume 12, Number 1, 2011

Fo� words

“

“

”

”

F or the past several decades, our society has been preoccupied with the subject of beauty and especially ways to make us all look and feel better about ourselves. So I applaud the entrance of a

new journal devoted to the scienti� c and artistic modalities to help patients look and feel their best. Orthodontics has once again taken the lead in convincing both the dental profession and the public of � rst thinking of the most ideal and long-lasting treatment to improve facial esthetics.

I was strongly in� uenced by my uncle, Dr Marvin C. Goldstein, a brilliant orthodontist who wrote one of the very � rst extensive papers on treating the adult patient. So my entire career has consisted of interdisciplinary consulta-tions and treatment plans. Unfortunately, over the past decade, the subject of esthetic compromise using porcelain laminates and other restorative so-lutions has created many ongoing problems, resulting in esthetic failures seen more and more throughout the world, when orthodontic treatment would have been the ideal and most ef� cient treatment plan. Therefore, I welcome the new journal Orthodontics: The Art and Practice of Dentofacial Enhancement and especially the most quali� ed team of Ra� and Marc at its helm.

—Ronald Goldstein, DDS

T he world of orthodontics has changed dramatically over the past decade. The concept and practice of interdisciplinary team treatment has opened up more opportunities for orthodontists

to participate in comprehensive case planning than ever before. However, as both treatment planning and treatment have become increas-

ingly sophisticated, so too have the demands placed on orthodontists by pa-tients and referring clinicians. Tooth position is only the starting point. In this exciting new world of orthodontic possibilities, orthodontists by necessity must have an even greater understanding of the various disciplines of dentistry.

When I became aware of the new direction that the World Journal of Orthodontics was taking, I felt con� dent that this new endeavor would bet-ter meet the daily challenges that orthodontists face and, at the same time, more effectively serve all dental disciplines. With new journal sections ad-dressing topics such as clinical controversies, treatment planning challeng-es, practice pearls, and management, I envision a publication which will generate great appeal for clinical collaboration in the interdisciplinary team, between study club members, and among dental colleagues.

I would like to congratulate Drs Ra� Romano and Marc Ackerman for their foresight, courage, and energy in introducing this highly relevant publica-tion, Orthodontics: The Art and Practice of Dentofacial Enhancement, to our profession.

—Michael Cohen, DDS, MSD

Scientific Innovation


1 Professor and Associate Director, Graduate Program in Orthodontics, Seton Hill University, Greensburg, Pennsylvania, USA.

2 Professor and Program Director, Graduate Program in Orthodontics, Seton Hill University, Greensburg, Pennsylvania, USA.

CORRESPONDENCE Dr Dan Rinchuse 510 Pellis Road Greensburg, PA 15601 Email: [email protected]

Modification of the bidimensional system

Daniel J. Rinchuse, DMD, MS, MDS, PhD1

Donald J. Rinchuse, DMD, MS, MDS, PhD2

In the mid 1970s, Schudy and Schudy developed and described an edgewise bimetric system in which there were brackets with 0.016-inch slots on the incisors and canines and brackets with 0.022-inch slots on the premolars and molars. Modeling after Schudy and Schudy, Gianelly devised a similar, preadjusted system called the bidimensional system, in which the incisor brackets have 0.018-inch slots while the remaining teeth have brackets with 0.022-inch slots. We have further modified the bidimensional system and developed a dual-slot system. Hence, this article compares the bidimensional and dual-slot systems and provides justification for both. The main concerns regarding the bidimensional and dual-slot systems are posterior “play” and lack of three-dimensional control. We rationalize both as well as the self-ligating hybrid and dual-slot system. ORTHO 2011;12:10–21.

Key words: bidimensional, bimetric, self-ligating, dual slot

Even though straight-wire, or preadjusted, edgewise appliances have achieved universal acceptance, there has been little discussion of their clinical advantages in regard to treatment time, chair time, comfort, hy-

giene, or treatment results. As Harradine noted: “No study ever demonstrat-ed that preadjusted edgewise appliances were superior to plain edgewise, but the former are overwhelming preferred for reasons that are regarded by clinicians as being self-evident and in no need of the highest order of scien-tific proof.”1 In a retrospective study comparing the treatment results of Roth (straight-wire) and standard edgewise appliances using two occlusal indices, there were no significant differences found between the two appliances.2 In fact, despite using the Roth appliance, experienced orthodontists still found it difficult to obtain all six keys to normal occlusion.


To this juncture, the purpose of this article is not to demonstrate superior-ity of a modifi ed bidimensional system over other edgewise appliances, but rather to justify our adaptations of Gianelly’s bidimensional system from a ra-tionale viewpoint with the best available evidence.

bIMETRIC SySTEM

In the mid 1970s, Schudy and Schudy3 described and rationalized a fi xed orth-odontic appliance system that incorporated two bracket slot sizes, which they called the bimetric system. It was a standard edgewise appliance system (zero base) in which the incisors and canines had brackets with 0.016-inch slots and the premolars and molars had brackets with 0.022-inch slots (Fig 1). They also argued for what they called the precision-fi t principle, meaning that in the fi n-ishing stages, the wires should fully engage the bracket slots, thus eliminating or signifi cantly reducing “play.” To fully engage and fi ll the dual-slot brackets, a 0.016 × 0.022-inch stainless steel wire is twisted and torqued 90 degrees distal to the canines. As a result, a ribbon archwire, 0.022 × 0.016-inch, is cre-ated in the posterior segments.

bIDIMENSIONal SySTEM

Modeling after Schudy and Schudy, Gianelly4 developed a preadjusted, edge-wise bidimensional system that had brackets with 0.018-inch slots on the inci-sors and 0.022-inch slots on the canines, premolars, and molars (Fig 2). Gianelly placed 0.022-inch slots on the canines, whereas Schudy and Schudy had 0.016-inch slots on the canines. Gianelly made cogent arguments for smaller bracket slots on the incisors (0.018 × 0.025-inch) for three-dimensional control and a tight fi t as well as for larger bracket slots (0.022 × 0.028-inch) on


the posterior teeth and a loose fit for sliding mechanics and space closure (Fig 3). (The terms tight fit and loose fit were descriptions used by Gianelly.)

Gianelly gave the following justifications for his bidimensional system: “The reason I did this was to combine precision with practicality. For example, one movement that requires torque control is the retraction of the maxillary incisors. In the edgewise technique, full engagement of the wire in the incisor brack-ets is generally necessary to control the axial inclination of the incisors during retraction. I use a 0.018 × 0.025-inch vertically slotted, programmed bracket on the central and lateral incisors and a 0.022 × 0.028-inch vertically slotted bracket posteriorly. For retraction, I simply insert a 0.018 × 0.022-inch wire for full engagement of the incisor brackets and retract the incisors bodily by means of sliding mechanics, because the wire is ’undersized‘ in the buccal segments. According to a New York University study, only 7% of wires ’fill the slots.’ My percentage during incisor retraction approaches 100%. The undersized poste-rior part of the wire also relieves me of the technical burden of adjusting the torque to the posterior brackets. My chair time is reduced, and I don't have to contend with loops that may impinge on the tissues.”5

Gianelly pointed out that few orthodontists fill the edgewise slots, especially for 0.022-inch slot users, so this is support for at least full 3D control of the inci-sors with 0.018 × 0.022-inch or 0.018 × 0.025-inch stainless steel archwires. For space closure, by sliding, Gianelly’s working wires are 0.016 × 0.022-inch

Fig 1 (Left) Schudy and Schudy3 advocated brackets with 0.016-inch slots for the incisors and canines (red) and brackets with 0.022-inch slots for the premolars and molars (green).

Fig 2 (Right) Gianelly’s bidimensional system4 uses brackets with 0.018-inch slots for the incisors (blue) and brackets with 0.022-inch slots for the canines, premolars, and molars (green).



Schudy and Schudy0.016-inch

Gianelly0.018-inch

0.016-inch 0.018-inch

0.022-inch 0.022-inch 0.022-inch 0.022-inch

0.022-inch 0.022-inch 0.022-inch 0.022-inch

Volume 12, Number 1, 2011

Rinchuse and Rinchuse

13


stainless steel or 0.018 × 0.022-inch stainless steel with crimp-on hooks distal to the lateral incisor brackets and closed nickel-titanium (Ni-Ti) coils attached to the crimp-on and molar hooks. He made an important point that for space closure, 0.017 × 0.025-inch or 0.018 × 0.025-inch stainless steel wires are not viable substitutes for the 0.016 × 0.022-inch or 0.018 × 0.022-inch stainless steel wires because the horizontal dimension of 0.025 inches creates too much resistance to sliding for space closure. Resistance to sliding is simply a combi-nation of classical friction and a coefficient of binding. In fact, Gianelly typically advocated using rectangular wires throughout treatment.

Nonetheless, a criticism of the bidimensional system is a lack of 3D control with full-sized 0.018 × 0.025-inch wires in the incisors but undersized in the posterior teeth due to the 0.022-inch slot. Gianelly’s counter was the same as Schudy and Schudy: To fill the posterior bracket slots, twist a 0.018 × 0.022-inch stainless steel wire 90 degrees distal to the lateral incisors and create a rib-bon arch with 0.022 × 0.018-inch stainless steel wire in the posterior. However, twisting or torquing a wire 90 degrees is cumbersome and unconventional for most orthodontists. Another option is to bend custom torque into rectangular archwires, as is traditionally done. Be that as it may, these solutions for lack of 3D control has never impressed orthodontists enough to adequately justify the bidimensional system. This in part may account for why only 4.7% of responding orthodontists reported routinely using the bi dimensional system.6

Fig 3 Brackets with (right) 0.018 × 0.025-inch incisor slots and (left) 0.022 × 0.028-inch posterior slots. With a 0.018 × 0.022-inch stainless steel working wire for sliding space closure, the incisor brackets are filled, while in the posterior brackets, the wire is un-dersized for reduced resistance to sliding.

0.018

0.022-inch 0.018-inch

0.018

“”

Resistance to sliding is simply a combination of classical friction and a coefficient of binding.




MODIFICaTION OF THE bIDIMENSIONal SySTEM: THE Dual-SlOT SySTEM

Having worked with Gianelly’s bidimensional system for over 20 years, we have developed some conceptual and mechanical alterations, which, for communi-cation purposes, we will call the dual-slot system. It must be noted, however, that Gianelly deserves the credit for providing the foundation and framework for our modification of the bidimensional system.

Proffit et al7 argued the advantages and disadvantages of the 0.018-inch slot vs the 0.022-inch slot from the perspective of sliding mechanics and torque control (Table 1). For instance, Proffit et al7 stated that sliding teeth along an archwire necessitates at least 2 mil (0.002-inch) of clearance— 4 mil (0.004-inch) of clearance is desirable. So, with this principle, the ad-vantage of a 0.022-inch slot would be that larger 18 mil (0.018-inch) wires could be used (compared to 16 mil [0.016-inch] wires in an 0.018-inch slot). Therefore, larger, stiffer wires would have fewer tendencies for notching and deformation. So, specifically for space closure by sliding, it would be advantageous to have brackets with 0.022-inch slots posterior to the ex-traction spaces for a looser fit, reduced resistance to sliding, and the use of stiffer wires.

However, for torque control in the incisors, it is better to have brackets with 0.018-inch slots because full-sized wires can be engaged if full 3D control is necessary. A 0.022-inch slot would not be advantageous for torque control since full-sized 0.022 × 0.028-inch wires are too stiff to be engaged into the bracket slots. Therefore, using Proffit et al’s7 rationalization, a bidimensional system would integrate the best of both the 0.018-inch and 0.022-inch slot systems: a tight fit in the incisors for full 3D control and a loose fit elsewhere for space closure by sliding. As an aside, various studies have shown that treat-ment times are shorter8–10 and outcomes may be better with a 0.018-inch slot compared to a 0.022-inch slot.8

Table 1 Comparison of the various slot sizes from a perspective of space closure (assuming sliding mechanics) and torque control

Slot size advantages Disadvantages

0.018-inch slot Anterior torque control: Full 3D control with 0.018 × 0.025-inch archwires

Space closure: Lighter undersized stainless steel wires more prone to deformation and notching

0.022-inch slot Space closure: Larger, stiffer undersized stain-less steel wires, less deformation and notching

Torque control: Full-sized 0.022 × 0.028-inch archwires are too stiff to be used so undersized finishing wires must be used

Bidimensional (dual-slot) 0.018- and 0.022-inch slots

Space closure: Larger, stiffer undersized rectangular wires (0.016 × 0.022- or 0.018 × 0.022-inch), less deformation and notching with 0.022-inch slots in posterior teeth, and effective 3D control of incisors during space closure with 0.018-inch slot in the anterior.

Anterior torque control: Full 3D control with 0.018 × 0.025-inch archwires

Possible loss of posterior 3D control with full-sized 0.018 × 0.025-inch archwires (counterarguments made in this article)



15

Scientific InnovationIn regard to criticism of play or lack of 3D control in the posterior segments

with the bidimensional or dual-slot system, as a conceptual difference, we have never twisted a 0.018 × 0.022-inch stainless steel wire distal to the lateral incisors in an attempt to enhance 3D control in the posterior, as advocated by Gianelly and Schudy and Schudy. If most orthodontists using a 0.022-inch slot finish with 0.019 × 0.025-inch wires,11 a full-sized 0.018 × 0.025-inch wire in a bidimensional or dual-slot system is not much different. Customized torque can still be used in the posterior segments if necessary.

Furthermore, it has been shown that there is tremendous morphologic vari-ability in the facial surfaces of teeth.12–15 Specifically, Germane et al12 reported the greatest variability in the posterior teeth. Even a very slight difference in bracket height placement, as little as 1 mm, could alter tooth inclination as much as 10 degrees.12 Creekmore and Kunik16 elaborated on this argument and showed that variations in tooth structure, such as variable facial surfaces, crown-root angulations, and atypical crown shape, warrant variations in tip, torque, rotation, and height parameters to obtain optimal results for each tooth.

In reference to a recent article by Mulligan,17 which differentiated the mo-ments created with full vs partial appliances, Keim18 noted that “one of the most common mistakes that arises as a result of standardized treatment proto-cols is the tendency to place full appliances in every case. Not only is this un-necessary in many patients, but if we analyze the resulting force systems, it may actually be contraindicated.” Furthermore, Mulligan19 often avoided bracket-ing the premolars and sometimes canines so that these teeth could be used to gauge whether the arches are expanding or constricting. Some have called this the neutral zone: equilibrium between lips, cheeks, tongue, and muscle forces exerted on teeth, particularly in the buccal segments, and the preexisting buc-cal segments may be in their most stable functional environment.

In reference to the “equilibrium effects on the dentition,” Proffit et al20 stat-ed that although masticatory forces are much stronger, the lighter pressures of the lips, cheeks, and tongue are much greater in duration, and these pres-sures, even at rest, are sustained most of the time and affect tooth position. To demonstrate this, they described the case of a woman who has tremendous unilateral splaying of the left posterior and anterior teeth subsequent to loss of lip and cheek pressure due to an infection and paralysis, with resulting pro-nounced tongue pressure. Arguing for a new soft tissue paradigm over the old “Angle ideal dental occlusion” paradigm, Profitt et al20 showed evidence for the new model. For instance, in regard to stability of results, the old model was related primarily to dental occlusion, whereas the new model relates stability primarily to soft tissue pressure and equilibrium effects. Therefore, soft tissue balance and equilibrium even after teeth are moved orthodontically will influ-ence tooth position. So, even if you have a prescription in your appliance that results in a certain 3D position of the teeth, the patient’s oral environment may provide the ultimate stable position of the dentition.

For these reasons and others, in the finishing stage of treatment, some or-thodontists use lighter wires, anterior segmental archwires and no posterior archwires with or without vertical elastics, circumferential retainers, and canine-to-canine vacuum-formed retainers to permit posterior settling. Again, the 3D control of the posterior segments that the orthodontist strived to obtain may be altered with settling and equilibrium of soft tissue on the teeth. Interesting-ly, Lyotard et al21 demonstrated the results of removing final archwires at the end of active orthodontic treatment for 4 weeks. Mandibular crowding, over-jet, and interproximal contacts worsened; however, marginal ridges, occlusal contacts, and total American Board of Orthodontics scores improved. Assum-ing that anterior segmental archwires are left intact, the authors concluded that

“

”

Some have called this the neutral zone: equilibrium between lips, cheeks, tongue, and muscle forces exerted on teeth, particularly in the buccal segments, and the preexisting buccal segments may be in their most stable functional environment.



Scientific Innovationtheir study supports the practice of removing the archwires from the posterior teeth a few weeks prior to debonding for settling and improved occlusion.

If orthodontists using 0.022-inch slot appliances finish with 0.019 × 0.025-inch stainless steel wires,11 it may be argued that these orthodontists have play throughout their system, whereas the dual-slot system has play only in the pos-terior and complete control of anterior teeth with full-sized 0.018 × 0.025-inch finishing wires. With play in the posterior and complete control in the anterior, teeth may level and align faster and space closure may be enhanced because of reduced resistance to sliding in the posterior segments.

If inclination/torque is dynamic and changes in the posterior, particu-larly the molars, over time as Marshall et al22 demonstrated, one might consider two possibilities: custom torque for each patient or to simply use the same for each patient. With normal, transverse growth of the max-illary and mandibular first molars from age 7.5 to 26.4 years, the maxillary molars upright lingually 3.3 degrees. Maxillary intermolar width increases 2.8 mm, and the mandibular molars upright 5.0 degrees and mandibular inter-molar width increases by 2.2 mm. Therefore, an attempt to prescribe a static facial torque in the buccal segments may ultimately be altered by growth or settling of the occlusion over time. So one may facetiously ask whether varying posterior 3D prescriptions for patients depending on their age is necessary.

Another critical question is whether specific, ideal torque values are any healthier than others. Is there morbidity generally associated with malocclusion? Ackerman and Proffit stated, “Although the concept of ideal occlusion has taken precedence as the ultimate goal in clinical orthodontics for some 110 years and serves well as an adopted arbitrary convention and a clinical gold standard, it has no verifiable scientific validity. No one has yet demonstrated that ideal occlu-sion provides significant benefits in oral or general health or that it significantly improves oral function.”23 Research seems to support Ackerman and Proffit’s po-sition. For instance, malocclusion is generally not associated with temporoman-dibular disorders (TMD), and orthodontics cannot lessen or prevent the future development of TMD.24–28 Contrary to what may seem reasonable, a recent sys-tematic review29 identified an absence of reliable evidence describing the posi-tive effects of orthodontic treatment on periodontal health. In fact, orthodontic therapy results in small detrimental effects to the periodontium: alveolar bone loss, gingival recession, and increased periodontal pocket depth.

Another point is related to the issue of expansion. Interestingly, many advo-cates of arch development and upright mandibular posterior teeth have inclination (lingual crown torque) prescriptions of –25 or –30 degrees, not –12 or –15, for the mandibular first molars. It is possible that expanded archwires may override the built-in prescription of –25 or –30 degrees and produce upright molars.30

Another difference in biomechanics between our system and Gianelly’s is that for space closure, Gianelly4 generally advocated separately retracting ca-nines and then the four incisors. On the contrary, our system employs en masse retraction for the the six anterior teeth, except for cases of anterior arch-length discrepancies or crowded anterior teeth, such as lingually blocked lateral inci-sors. Then, we separately retract the canines only to relieve crowding. This treat-ment philosophy is also held by Burstone, who said: “Since relatively low forces are capable of retracting six teeth, there is little logic to separate retraction of canines followed by retraction of the four incisors. For that reason, only patients who have anterior arch-length problems with anterior crowding require separate canine retraction.”31 This would prevent round-tripping teeth.

This is supported by Heo et al,32 who found no significant difference in posterior anchorage loss between en masse retraction of the six anterior teeth and separate, two-step retraction of the canines followed by the four incisors;

“”

. . . an attempt to prescribe a static facial torque in the buccal segments may ultimately be altered by growth or settling of the occlusion over time.



17


two-step retraction took longer. Likewise, Xu et al,33 in a randomized clinical trial comparing en masse and two-step retraction in 64 growing boys and girls with Angle Class I and II malocclusions requiring maxillary premolar extractions and maximum anchorage using an MBT prescription and 0.022 × 0.028-inch bracket slots, headgear, and some transpalatal appliances, found that contrary to what some clinicians believe, two-step retraction is not more effective than en masse retraction in preventing clinically meaningful anchorage loss. And, again, two-step retraction lengthens treatment time.

As an example, if you want to close maxillary first premolar extraction spaces by 8 mm, assume that you can close the space 1 mm per month for a total of 8 months to retract the canines and then another 8 months to retract the incisors. However, if you retract the six anterior teeth en masse, you can close the space in 8 months, saving 8 months of treatment. Moreover, a recent study concluded that there should be no expected difference in external apical root resportion between two-step and en masse space closure procedures.34

As mentioned previously, Gianelly routinely used rectangular wires throughout treatment, whereas our initial wires are generally round Ni-Ti wires, as advocated by Proffit. For instance, Proffit et al7 state that, “A tightly fitting resilient rect-angular archwire for initial alignment is almost always undesirable because not only is frictional resistance to sliding likely to be problematic, the wire produces back-and-forth movement of the root apices as the teeth move into alignment.”

With moderate to severely rotated teeth, resilient round wires would offer another advantage because they have flexibility in both the horizontal and ver-tical dimensions, whereas resilient rectangular wires have more flexion in the vertical dimension and limited flexion in the horizontal dimension. Table 2 is an overall comparison of differences between the Gianelly bidimensional tech-nique and the dual-slot system.

Table 2 Comparison of the differences between Gianelly’s bidimensional technique and the dual-slot system

Comparisons bidimensional technique Dual-slot system

Canine vs en masse retractions

Canine retraction En masse retraction except for anterior arch-length discrepancies

Initial wires Generally rectangular Generally round

Vertical slots Yes, for auxiliaries, and uprighting springs in canines for anterior labial forces in the mandibu-lar arch in Class II extraction cases to prevent an overjet with intra-arch mechanics

No

Ball hooks No Yes, on most teeth

Bracket torque No posterior torque More torque on anteriors and posterior torque

Rationalization for lack of 3D control in posterior teeth

Twist a 0.018 × 0.022-inch stainless steel wire 90 degrees distal to the lateral incisors to create a ribbon arch

Can place conventional torque in archwires More variability of facial surfaces in the posterior teethMulligan Mechanics —generally premolars and sometimes canines are not bracketed, especially with use of V-bendsNeutral zoneWith growth, molars tend to upright

Self-ligation model No Propose dual-slot self-ligating and hybrid self-ligating models




SElF-lIGaTION: FuTuRE HybRID aND Dual-SlOT SElF-lIGaTING SySTEMS

Rinchuse and Miles35 described a hybrid self-ligating bracket systems in either entirely 0.018-inch slots or entirely 0.022-inch slots in which the anterior brack-ets are active with a spring clip and the posterior brackets have a passive slide, very similar to a bimetric, bidimensional, or dual-slot system. Since the gingival horizontal wall is compromised by an obliquely inclined spring clip, the ac-tive self-ligating brackets are smaller than their conventional counterparts and not truly 0.018 × 0.025- or 0.022 × 0.028-inch. Therefore, this hybrid system would have so-called reduced bracket slots in the anterior for a tighter fit and enhanced 3D control, especially with undersized 0.019 × 0.025-inch stainless steel finishing wires in 0.022-inch slots, and a looser fit with possibly reduced resistance to sliding with passive brackets36–38 in the posterior for leveling, alignment, and space closure.

In an in vitro study, Badawi et al39 found that active self-ligating brackets are more effective in torque expression than passive self-ligating brackets in 0.022-inch slots and 0.019 × 0.025-inch stainless steel wire. Likewise, if many orthodontists use a 0.022-inch slot and only finish with 0.019 × 0.025-inch stain-less steel wire,11 it might be desirable to use an active self-ligating system since there may be more enhanced 3D control and dental esthetics of the incisors. However, if a clinician is filling the 0.018-inch bracket slots with 0.018 × 0.025- or 0.0175 × 0.025-inch finishing wires, a passive self-ligating system might be advantageous, possibly reducing resistance to sliding in the initial stages of treatment. However, this is controversial, with notching and binding as variables affecting resistance to sliding.40

To obtain excellent 3D control in the anterior teeth and at the same time have even more reduced resistance to sliding in the posterior, a dual-slot self-ligating system can be used with active 0.018-inch slot anterior brackets and passive 0.022-inch slot posterior brackets. Other self-ligating permutations are all-active or all-passive dual-slot systems. Table 3 codifies the possible hybrid

Table 3 Summary of the possible hybrid or dual-slot self-ligating systems adapted after Rinchuse and Miles35

bracket system Slot size (inches) active Passive

Hybrid self-ligating 0.018-inch 0.018 Anterior Posterior

Hybrid self-ligating 0.022-inch 0.022 Anterior Posterior

Dual-slot self-ligating 0.0180.022

AnteriorPosterior

Dual-slot self-ligating active 0.0180.022

AnteriorPosterior

Dual-slot self-ligating passive 0.0180.022

AnteriorPosterior

“

”

With moderate to severely rotated teeth, resilient round wires would offer another advantage because they have flexibility in both the horizontal and vertical dimensions, whereas resilient rectangular wires have more flexion in the vertical dimension and limited flexion in the horizontal dimension.



19

Scientifi c Innovation

and dual-slot self-ligating systems. Figure 4 shows the permutations of ma-nipulating slot size, active or passive self-ligating brackets, and a hybrid system (same slot size but active anterior and passive posterior brackets).

Paik et al41 applied the principles that Rinchuse and Miles35 developed to describe a hybrid bracket-tube system called the hybrid sliding mechanics of low friction, which is a combination of passive self-ligating brackets on the pre-molars, conventional tubes on the molars, and conventional twin brackets on the anterior teeth. However, much of the rationale for this system is based on in vitro data regarding friction and passive self-ligating brackets.

CONCluSION

We have presented a cursory review of the bimetric and bidimensional systems juxtaposed with a dual-slot system that offers an alternative to Gianelly’s sys-tem. Furthermore, we codifi ed Rinchuse and Miles’35 thoughts on hybrid and dual-slot self-ligating systems.

aCKNOWlEDGMENTS

Since we were orthodontic residents at the University of Pittsburgh in 1974, we have been impressed with Dr Anthony Gianelly’s (1936–2009) research, articles, and particularly his bi-dimensionsal system. He was a very unassuming and humble man. We have used a bidimen-sional prescription that we have modifi ed for over two decades, which this paper addresses. However, without Tony’s concepts and principles, this paper would not have been possible.

Dual-slot system (different slot sizes, but same self-ligating brackets) • 0.018-inch slots on the anterior teeth and 0.022-inch slots on the posterior teeth • Conventional • Active self-ligating • Passive self-ligating

Hybrid system (same slot size, but different self-ligating brackets) • Mimics a bidimensional or dual-slot system • Active anterior and passive posterior self-ligating brackets • Stays in the same slot size (0.018- or 0.022-inch)

Dual-slot –hybrid system (different slots and different self-ligating brackets [active and passive]) • 0.018-inch slot anterior brackets and 0.022-slot posterior brackets • Active anterior brackets and passive posterior brackets

Fig 4 The various permutations of self-ligating systems.



Scientific InnovationREFERENCES

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11. Sheridan JJ. The reader’s corner. J Clin Orthod 2003;37:27–29.

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15. Miethke RR, Melsen B. Effect of variation in tooth morphology and bracket position on first and third order correction with preadjusted appliances. Am J Orthod Dentofacial Orthop 1999;116:329–335.

16. Creekmore TD, Kunik RL. Straight wire: The next generation. Am J Orthod Den-tofacial Orthop 1993;104:8–20 [erratum 1993;104:20].

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18. Keim RG. Common sense revisited. J Clin Orthod 2009;43:357–358.

19. Mulligan TF. Common Sense Mechanics in Everyday Orthodontics. Phoenix: CSM, 1998.

20. Proffit WR, Fields Jr HW, Sarver DM. Con-temporary Orthodontics, ed 4. St Louis: Mosby, 2007:6, 145–147.

21. Lyotard N, Hans M, Nelson S, Valiathan M. Short-term postorthodontic changes in the absence of retention. Angle Orthod 2010;80:1045–1050.

22. Marshall S, Dawson D, Southard KA, Lee AN, Casko JS, Southard TE. Transverse molar movement during growth. Am J Orthod Dentofacial Orthop 2003; 124:615–624.

23. Ackerman JL, Proffit WR. Guest editorial. A not-so tender trap. Am J Orthod Dento-facial Orthop 2009;136:619–620.

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1 Formerly, Chair and Program Director, Jacksonville University School of Orthodontics, Jacksonville, Florida, USA; currently, Director of Orthodontics, Children’s Hospital Boston, Boston, Massachusetts, USA.

2 Professor, Department of Economics, Jacksonville University, Jacksonville, Florida, USA.

CORRESPONDENCE Dr Marc Bernard Ackerman Children’s Hospital Boston 300 Longwood Ave Boston, MA 02115 Email: [email protected]

Posttreatment compliance with removable maxillary retention in a teenage population: A short-term randomized clinical trial

Marc Bernard Ackerman, DMD, MBA1

Barry Thornton, EdD2

Removable retainer wear is most related to patient comfort and acceptance. Patient compliance is essential for retention and maintenance of the orthodontic treatment results. Even though patients are educated about the need for prolonged retention after active treatment and asked to sign informed consent regarding the risk of noncompliance (relapse) prior to treatment, most orthodontists would estimate that at least half of their teenage patients do not comply at optimal levels. The aim of the present study was to quantify teenage patient compliance with removable maxillary retention and compare actual usage vs prescribed usage between subjects who knew they were being monitored via an implanted microsensor in the retainer and those subjects who were unaware of any monitoring. The final sample consisted of 9 subjects in the test group (5 males and 4 females) and 10 subjects in the control group (4 males and 6 females). The evidence suggests that individuals who were made aware of the orthodontist’s ability to monitor compliance wore the device for a significantly larger number of hours per day than those who were unaware of this fact. Patients reporting full usage of the retainer wore the appliance a mean of 4.3 hours more per day than those reporting less than full usage, holding all other variables constant. Patients who misrepresented their retainer use (reported full usage but wore the device less than 19 hours per day) wore the appliance a mean 12.4 hours less than the more honest patients who participated in the study. ORTHO 2011;12:22–27.

Key words: orthodontic retention, compliance, microsensor

Orthodontics is concerned with variations in dentofacial traits that may affect an individual’s overall well-being. Dentofacial traits are defined as hard or soft tissue characteristics or combinations of characteristics

that distinguish an individual’s facial appearance and determine their level of oral and social function. Orthodontic intervention includes therapies that enhance dentofacial traits, thus improving a person’s health.1 Contemporary orthodontic treatment is a two-step process: active treatment and retention. Active treatment involves modification of tooth position via fixed applianc-es or removable clear aligners. Retention refers to the period of supervised maintenance of the teeth in their corrected positions via retainers after active treatment. Of all the dentofacial traits, tooth alignment is most affected by a patient’s compliance with retention.


Nearly a century ago, Norman Kingsley stated, “The success of orthodontia as a science and an art now lies in the retainer.”2 To date, there is little con-sensus in the orthodontic literature on the most effective retention strategy in clinical practice.3 However, many orthodontists concur that retention is abso-lutely necessary for three principal reasons: (1) gingival and periodontal tissues are affected by orthodontic tooth movement and require time for reorganiza-tion when active appliances are removed4; (2) teeth may be in an inherently un-stable position after active treatment, such that soft tissue pressure constantly produces a relapse tendency; and (3) changes produced by growth may alter treatment results in growing subjects.5 Reorganization of the periodontal liga-ment (PDL) occurs over a 3- to 4-month period after active appliance removal.4

Reorganization of the collagenous and elastic fi bers in gingivae occurs more slowly than that of the PDL.6 The collagenous fi ber networks within gingivae complete their reorganization within 4 to 6 months after removal of active appliances. The elastic supracrestal fi bers remodel very slowly and can exert forces capable of tooth movement even 1 year after active appliance removal.

There is tremendous variation in retention protocols used in contemporary orthodontic practice. However, there is general agreement among orthodon-tists that regardless of the length of the supervised retention period or the prescribed daily schedule of retainer wear, patients must have some type of retention following active treatment to maintain treatment results. Although data in the scientifi c literature are scant, some authors have suggested that retention appliances be placed immediately after the active appliances are removed,4 worn full-time (except during meals) for the fi rst 3 to 4 months after active appliance removal, and then worn part-time for 1 or 2 years thereafter.5

In practice, most orthodontists develop their own retention protocol based either on what they were taught in residency or their clinical experience after some years of practice.

Removable retainer wear is most related to patient comfort and acceptance.7

Patient compliance in retention is essential for maintenance of the orthodontic result. Although subjects are educated about the need for prolonged retention after active treatment and are asked to sign an informed consent form regard-ing the risk of noncompliance (relapse) prior to treatment, most orthodontists estimate that at least half of their teenage patients comply below optimal lev-els. Noncompliant patients experience a relapse of tooth crowding or spacing within the fi rst few months of retention. Patients who do not comply properly in the initial retention period are at risk for signifi cant relapse in the long term. With no way of determining whether patients follow the prescribed plan of retention, orthodontists have been unable to assess whether changes in tooth position are a result of poor retainer compliance or ineffective retainer design.

Posttreatment compliance with removable maxillary retention in a teenage population



This inability to accurately monitor or police patient retainer compliance has also negatively affected patient motivation during this important phase of treat-ment. A new methodology for incorporating a microsensor to quantify patient compliance was published in the orthodontic literature.8

The aim of the present study was to quantify teenage patient compliance with removable maxillary retention and compare actual vs prescribed usage between subjects who knew they were being monitored via a microsensor in the retainer and those subjects who were unaware of any monitoring. The null hypothesis was that there was no difference in retainer usage between those subjects who knew they were being monitored and those subjects who were unaware of it.

METHODS

Once study approval from the Jacksonville University Institutional Review Board was granted, patients approaching the end of fixed appliance ther-apy who met the inclusion and exclusion criteria (Table 1) were invited to participate in the study. Written informed consent was obtained from each patient or patient’s parent or guardian prior to the initiation of retention, and subjects were free to withdraw at any time during the study.

“”

There is tremendous variation in retention protocols used in contemporary orthodontic practice. However, there is general agreement among orthodontists that regardless of the length of the supervised retention period or the prescribed daily schedule of retainer wear, patients must have some type of retention following active treatment to maintain treatment results.

Table 1 Study criteria

Inclusion criteria Exclusion citeria

• Subjects aged between 13 and 19 years• Treatment plan includes maxillary Hawley

retainer use• No history of retainer wear• No missing anterior teeth requiring

pontic teeth on the retainer• Ideal alignment of maxillary anterior teeth

at debonding

• Phase I–treated patients• Craniofacial syndromes• Poor compliance during active orthodontic

treatment (such as multiple missed appointments or excessive appliance breakage)


Ackerman and Thornton

25


Twenty-three subjects were recruited. Subjects were randomly assigned to the test (aware of monitoring) or control group (unaware of monitoring). The test group initially consisted of 11 subjects (5 males and 6 females) with a mean age of 15.4 years; the control group initially consisted of 12 subjects (5 males and 7 females) with a mean age of 15.6 years. Each subject received a maxillary Hawley retainer constructed of wire and pink orthodontic acrylic with a blue microsensor embedded in the middle of the palatal acrylic. The word “smart” was stamped on the sensor and visible through the acrylic (Fig 1). All subjects were asked to wear the appliance at all times, with the exception of during meals and contact sports (approximately 20 hours per day) for the first month after fixed appliance therapy.

Subjects were recalled 1 month after debonding. Retainer compliance was calculated using the methodology described in a previous publication.8 Sub-jects were asked to subjectively rate their compliance with the prescribed hours of retainer wear. Three options were given: (1) worn as prescribed, (2) moder-ately worn (at least half of the time), and (3) poorly worn (less than half of the time). Four subjects dropped out of the study: Three subjects lost their retain-ers in the first month after debonding, and one patient’s microsensor malfunc-tioned. The final sample consisted of 9 subjects in the test group (5 male and 4 female) and 10 subjects in the control group (4 male and 6 female).

Fig 1 The USB-powered sensor reader with a study retainer in the reading position.

Posttreatment compliance with removable maxillary retention in a teenage population



RESulTS

Multiple regression was employed to determine whether a patient’s retainer usage was influenced by the knowledge that his or her use of the device was being monitored. The dependent variable was the number of hours that the patient actually wore the retainer each day. The total number of observations on the dependent variable was 570, based on a 30-day trial for 19 patients. The dependent variable was regressed on four independent variables. The first independent variable, ranging from 1 to 30, was the day of the trial. The second independent variable was a binary variable that was set equal to 1 if the patient was aware of monitoring and 0 if he or she was unaware. The third independent variable was a binary variable that was set equal to 1 if the pa-tient reported full usage of the appliance and 0 if he or she did not. The fourth independent variable in the model was a binary variable that was set equal to 1 if the patient misrepresented retainer usage and 0 if he or she was truthful. An example of a misrepresentation would be if the patient wore the appliance for less than 19 hours and reported full usage. The determination of 19 hours as the minimum value for full usage was based on an analysis of the sample data. The third quartile for the number of hours per day patients used the appliance was 19 hours. Patients who reported wearing the retainer for 19 hours or more per day were considered to have achieved full usage, while those patients wearing the retainer less than19 hours per day were classified as having less than full usage.

The overall evaluation of the model confirms that it has significant explanatory power (computed F = 236.77, with an associated P value of .000) (Table 2). This model explains 62.4% of the variation in the actual number of hours patients wore their retainers. All of the independent variables selected in the model were significant at less than .01.

DISCuSSION

The primary issue to be investigated was whether the actual amount of time a patient wore the retainer during the 30-day trial was impacted by their knowl-edge of the researcher’s ability to monitor compliance. The sample evidence suggests that individuals who were made aware of the ability to monitor com-pliance wore the device for a significantly larger number of hours per day than those who were unaware of this fact. The results of the analysis indicate that patients made aware of the presence of the ability to monitor compliance wore the device 2.3 hours more per day than the unaware patients, holding every-thing else constant.

Table 2 Multiple regression results

Predictor Estimated coefficient T ratio P

Constant 17.5 16.9 .000

Day –0.2 –8.1 .000

Aware 2.3 4.9 .000

Report 4.3 5.7 .000

Lie –12.4 –24.2 .000

F = 236.77, P = .000, adj R2 = 62.4%.


Ackerman and Thornton

27

Scientific InnovationThere was a tendency for subjects in the study to reduce their use of the

appliance over time. The estimated coefficient on the variable for the day of the trial shows that with each passing day, patients wore the retainer a mean 0.2 hours (12 minutes) less. Over the life of the study (30 days), this is 6 hours per day.

In addition, patients reporting full usage of the retainer wore the appliance a mean 4.3 hours more per day than those reporting less than full usage, hold-ing all other variables constant. Those who misrepresented their retainer us-age wore the appliance an average of 12.4 hours less than the more honest patients that participated in the study.

CONCluSION

From the results of this clinical trial, it would appear that there is a significant disparity between the amount of actual and prescribed retainer usage in this sample of teenage orthodontic patients. Specifically, patients who knew that their orthodontist was actively monitoring hours of retainer wear clearly ex-hibited better compliance than those who were unaware of the monitoring. However, very few patients in the test group demonstrated full-time retainer wear. It would appear that in this teenage sample, asking patients to wear their removable maxillary retainers half-time (12 hours per day) would have been a more reasonable prescription for compliance. Future research utilizing micro-sensor technology will permit orthodontists to correlate the extent of tooth alignment relapse with retainer compliance.

ACKNOwlEDgMENTS

Dr Ackerman wishes to thank the orthodontic residents at Jacksonville Uni-versity for their assistance with the execution of this study. This study was funded by Scientific Compliance. Neither author has financial interest in Scien-tific Compliance. Dr Ackerman is the former chief scientific officer of Scientific Compliance.

REFERENCES

1. Ackerman MB. Enhancement Orthodon-tics: Theory and Practice. Ames, Iowa: Blackwell, 2007.

2. Kingsley NW. A letter to the Alumni Soci-ety of the Angle School of Orthodontia. Am Orthod 1908,125.

3. Littlewood SJ, Millett DT, Doubleday B, Bearn DR, Worthington HV. Retention procedures for stabilizing tooth position after treatment with orthodontic braces. Cochrane Database Syst Rev 2006;1: CD002283.

4. Reitan K. Principles of retention and avoidance of posttreatment relapse. Am J Orthod 1969;55:776–790.

5. Proffit WR, Fields HW, Sarver DL. Con-temporary Orthodontics, ed 4. St Louis: Mosby, 2007:623.

6. Reitan K. Tissue rearrangement during the retention of orthodontically rotated teeth. Angle Orthod 1959;29:105–113.

7. Wong P, Freer TJ. Patients’ attitudes to-wards compliance with retainer wear. Aust Orthod J 2005;21:45–53.

8. Ackerman MB, McRae MS, Longley WH. Microsensor technology to help monitor removable appliance wear. Am J Orthod Dentofacial Orthop 2009;135:549–551.

“”

… it would appear that there is a significant disparity between the amount of actual and prescribed retainer usage…

Technology


1 Professor, Department of Orthodontics, Dental Faculty, University of Aleppo, Aleppo, Syria.

2 Lecturer, Department of Orthodontics, Dental Faculty, University of Aleppo, Aleppo, Syria.

CORRESPONDENCE Dr Mahmoud Al-Suleiman Department of Orthodontics Dental Faculty University of Aleppo Al-Fateh St Aleppo, Syria Email: [email protected]

AUSOM: A 3D placement guide for orthodontic mini-implants

Mahmoud Al-Suleiman, DDS, COS, PhD1

Manal Shehadah, DDS, MSc2

Aim: Anchorage management is an important issue in orthodontic treatment and plays a big role in the success or failure of orthodontic treatment. Using a mini-implant system as skeletal anchorage is a suitable solution if maximum or absolute anchorage control is required. Applying mini-implants requires pinpointing their optimal position to prevent damaging adjacent anatomical structures. There are three considerations in locating proper mini-implant position: the point of implant insertion, the angle of implant insertion in the anterior-posterior direction, and the angulation of implant insertion in the vertical plane. Here, we illustrate a new three-dimensional mini-implant guide (Aleppo University Surgical Orthodontic Miniscrew Guide [AUSOM]) developed for determination of ideal mini-implant placement and demonstrate AUSOM’s role in mini-implant success. Methods: After reviewing of articles about mini-implants in orthodontic treatment, we determined the characteristics of an ideal orthodontic implant guide (IOIG). We invented a new instrument, AUSOM, that consists of four components: a horizontal part, a vertical part, a graduation guide, and film-holding part. Forty mini-implants were inserted for orthodontic treatment purposes; AUSOM and wire guides were used to insert the mini-implants. Conclusion: We found AUSOM to be a practical and accurate device. It works as a radiographic-locating device and a mini-implant surgical placement guide. The failure rate of mini-implants placed by AUSOM was lower than that of those placed by simple metallic guides. Clinical randomized studies must be carried out to prove AUSOM’s role in improving the success rate of mini-implant placement. ORTHO 2011;12:28–37.

Key words: AUSOM, mini-implant, mini-implant guide, optimal screw implant, position, skeletal anchorage


Anchorage is an important issue in orthodontics, and it plays a vital role in successful treatment results.1–3 It can been defi ned as the nature and degree of resistance to displacement provided by anatomical units or

intra- or extraoral devices used for the purpose of performing tooth move-ment.1–3 Undesired movements were a clinical complication caused by insuf-fi cient resistance values of anchoring teeth.1,2 Anchorage loss can be caused by a low level of patient cooperation and cannot be considered stable anchor-age.1,2 To overcome these problems, skeletal anchorage has been increasingly incorporated into orthodontic treatment.4–12 The need for absolute anchorage began with conventional dental,13 retromolar,14 and palatal implants.13–15 How-ever, space limitations, implant costs, and diffi cult connections to orthodontic appliances encouraged the rapid development of smaller devices that can be placed in various locations in the dental arch. Mini-implants and miniplates specifi cally designed for orthodontic use satisfy some of these requirements and are being progressively adopted in clinical practice.7,16,17

Skeletal anchorage systems include all devices that are fi xed to bone for the purpose of enhancing orthodontic anchorage either by supporting the teeth of the reactive unit or altogether obviating the need for the reactive unit.18 Tem-porary anchorage devices (TADs) refer to devices placed specifi cally to provide orthodontic anchorage and are removed upon completion of biomechanical therapy; examples include onplants, zygoma wires, mini-implants, and mini-plates.3,7,11,16,17,19,20 On the other hand, stationary anchorage, such as inten-tionally ankylosed teeth and conventional dental implants, refers to devices that can be used to provide skeletal orthodontic anchorage and do not need to be removed after the completion of orthodontic treatment.18

Mini-implants have been introduced into orthodontics for various purposes, such as canine and anterior teeth retraction, en masse anterior retraction, molar uprighting, distalization, and protraction.9,20–23 They have the advantages of small size; more implant sites and indications; simplicity of placement; short

AUSOM: A 3D placement guide for orthodontic mini-implantsTechnology


or even no waiting period before loading; no need for laboratory work; easy removal after treatment; and lower cost than implants, onplants, and mini-plates.24 Two types of mini-implants have been used in orthodontics: predrilled and self-drilling.25 In an experimental study, it was reported that self-drilling mini-implants have less mobility and more bone-to-metal contact than their predrilled counterparts.25

The implant site should have good bone density and thickness to provide enough bone around the screw.8,22,26 Improper positioning may result in inter-ference with required tooth movement and limit the effectiveness of the skeletal anchorage.16 Several factors might influence the stability and failure rates of mini-implants, including vertical or sagittal placement27 and the proximity to a root.28 Insertion techniques should maximize the available bone volume while avoiding adjacent anatomical structures, such as dental roots, nasomaxillary cavities, and neurovascular tissues.29 –32

Placing a mini-implant without a surgical guide increases the risk of prob-lems.4,12,27 Therefore, to determine the optimal position and suitable inser-tion direction of mini-implants, different methods have been used, including radiographs,26,33,34 computed tomography (CT), cone beam CT, and dental CT scans.26,31,33 –36 Mini-implants placed manually can penetrate the root den-tin.27 The type of surgical procedure was the most significant predictor for failure, followed by mini-implant placement at a high level (in nonkeratinized mucosa).37

There are three considerations when determining ideal mini-implant posi-tioning:

1. The point of implant insertion2. Ensuring the angle of implant insertion is anterior-posterior to prevent

harm to the adjacent dental roots3. The recommended angulations of insertion in the vertical plane (20 to 30

degrees in the mandible and 30 to 40 degrees in the maxilla8,22,26)

Wu et al reported that screw placement without an accurate surgical guide results in 20% of injuries during positioning.38 Accidental impingement of mini-implants into the dental root and periodontium is a possible complica-tion, especially in the interradicular areas. However, histologic studies have shown that repair of the periodontal tissue is possible in cases of accidental contact of dental roots.39,40 Cementum can be significantly damaged when mini-implants are screwed against the root surface. In these cases, the screw should be immediately removed,41 and the tooth should not be moved for 3 to 4 months to reduce root resorption risks.39,42 Screws placed in the periodontal ligament have a greater failure rate.28,38,39

The aim of this article is to describe a three-dimensional universal guide designed to determine the ideal position and placement of orthodontic mini-implants.

“”

Insertion techniques should maximize the available bone volume while avoiding adjacent anatomical structures, such as dental roots, nasomaxillary cavities, and neurovascular tissues.


Al-Suleiman and Shehadah Technology

31

MATERIAlS

After reviewing articles written about mini-implant usage in orthodontic treat-ment, it was concluded that are many devices are used in locating implant placement. These methods can be lumped into three categories: wire or me-tallic guides, surgical templates, and other devices and methods.26,43

Wire and metallic guidesA wire guide is a practical radiopaque marker formed from a brass or stainless steel wire.22,32,44,45 It is inexpensive, simple to fabricate, and easy use, but it pro-vides limited, two-dimensional information on the implant site. Because rela-tive positions may be inconsistent in different radiographic views, the wire and metallic guides are not always accurate.43 Furthermore, because guides do not prevent deviation of the pilot drill, they do not eliminate the risk of root dam-age.34 A Kim stent is a 3D method for positioning mini-implants that prevents root damage and improves the insertion success rate.43 The wire guide (0.0215 × 0.028-inch wire) consists of two parts: a positioning gauge, which is attached to the tooth distally to the mini-implant placement site, and a directional guide, which is attached to the tooth mesially to the mini-implant.43

Surgical templatesSurgical stents, guides, and templates can transfer a radiographically planned, 3D implant position to the surgical site more accurately than wire or metal-lic guides.26 Kyung et al used vertical and mesiodistal measurements from a lateral cephalogram to construct an acrylic marker, but this provides only a 2D location.9 Kitai et al described a technique requiring several complicated and expensive steps: a CT scan of a template in the appropriate position, a digital surface scan of the working cast and template, production of a stereo-lithographic model, and fabrication of an acrylic or prefabricated removable stent.36 Morea et al designed an acrylic stent with a metal sleeve to guide the pilot drill for nondrilling mini-implants, but the initial wax fixation of the sleeve to the working cast seems fragile, there appears to be no access for external irrigation, and retention of the acrylic stent may be problematic.32 Cousley and Parberry modified the 3D stent.26 The design and fabrication are simple, and the stent provides reliable guidance for either the pilot drill or the self-drilling mini-implant in terms of both location and angulation. The stent allows access for both visual monitoring and saline irrigation, but this takes time and effort for the laboratory work, and fine adjustments cannot be made.

Other devices and methodsThese devices do not have standard forms and were fabricated to overcome problems found with the two categores previously mentioned.

Suzuki 3D guide. The Suzuki guide consists of a vertical arm (available in 5, 7, and 9 mm). One end is attached to the main orthodontic archwire with a Gurin lock, and the other is connected to a stainless steel tube 5-mm long and 3 mm in diameter. The tube is used to identify the optimal implant site on bitewing radiographs and guide the drilling of the pilot hole and placement of the mini-implant. The Suzuki guide has a simple design, is adjustable in the horizontal dimension, and is comfortable for the patient.46

3D radiographic surgical guide. This consists of two items. The first is a 0.045-inch stainless steel telescopic tube soldered to the end of a vertical arm, which is attached to a horizontal arm by a Gurin lock. Both arms are made of 0.021 × 0.025-inch stainless steel wire, allowing the guide to be inserted into the fixed orthodontic appliance. The second is a modified radio-graphic positioner.33



METHOD

From previous critical reviews of guides and methods used to determine op-timal position and correct placement of orthodontic mini-implants, it can be concluded that the ideal orthodontic implant guide (IOIG) must have the fol-lowing characteristics:

• Versatile (allows the localization of the ideal mini-implant position by using periapical radiographs and at the same time be used to apply the orthodon-tic mini-implant33)

• 3D adjustable (can be adjust to locate the point of implant insertion,8,22,26 the angle of implant insertion in the anterior-posterior direction to avoid hurting the adjacent dental roots,8,22,26 and the recommended angulations of implant insertion in the vertical plane8,22,26)

• Universal (can be used for both arches and both sides [right and left] to save time and money and with both self- and non–self-drilling mini-implants46)

• Comfortable (does not bother or annoy patients during use) • Simple design (easy to use, does not waste time, and inexpensive)• Sterilizeable (can be used on other patients)

Taking all this into account, we invented a 3D placement guide for orth-odontic mini-implants—the Aleppo University Surgical Orthodontic Miniscrew (AUSOM). It is used to determine the ideal position and to place mini-implants in the optimal recommended position.

The AUSOM consists of four pieces (Fig 1).

1. The vertical part is a graduated stainless steel round cogged wire 1.2 mm in diameter that acts as a millimeteric guide to locate the position of mini-implants in the vertical direction. It has a lock that will be fixed to a rectan-gular orthodontic wire connected to the fixed appliance (adjacent bracket slots and molar band tubes).

Fig 1 AUSOM parts. (a) Vertical and horizontal parts as well as placement guide. (b) Diagram of how vertical part is fixed to the archwire and how the film-holding part connects between the molar tube and periapical radiograph film holder.

a bVe

rtic

al p

art

Horizontal part

Rinn XCPFilm holding part

Periapical radiograph film

Placement guide



33

2. The horizontal part is a graduated stainless steel round cogged wire 1.2 mm in diameter that acts as a millimeteric guide to locate the position of mini-implants in the horizontal direction and has a cylinder with a lock. It is movable in the vertical direction by sliding the vertical part. Once the desired height is reached, the lock can be closed. The horizontal part also holds the placement guide.

3. The placement guide is a vertical round wire 1 mm in diameter. It has a cylinder on the end, which works as a guide to place the mini-implant. The angle between the cylinder axis and the vertical wire is adjustable. The other end has two perpendicular cylinders, which makes it able to rotate around its axis and move horizontally.

4. The film-holding part is a wire that extends from the facebow tube of the molar band and inserts into the perapical radiograph holder, which is a part of the Rinn XCP film-holding system that depends on paralleling technique for dental radiography.

To evaluate the efficiency of AUSOM in the placement of mini-implants, a pre-liminary study was carried out. Twenty patients (13 male and 7 female) whose orthodontic treatment plans included mini-implants were selected. Each patient received two mini-implants in symmetric positions between the maxillary second premolar and first molar. One of the mini-implants was placed with AUSOM, while the other was placed with a traditional wire guide. To detect mini-implant position, periapical radiographs were taken before implantation with the guide in its place and after mini-implant placement. To assess mini-implant position in regard to tooth roots in periapical radiographs, a scale of four degrees was created: (1) unaccept-able position, (2) acceptable position, (3) good position, and (4) very good position.

One week after insertion, mini-implants were loaded and stability of the mini- implants was examined. The results showed that the success rate of the mini-implants placed with AUSOM was 95%, while the success rate of those placed with the wire guide was 75% (Table 1). The significant deference in failure rate of mini-implants was P = .046 (Table 2). Tables 3 and 4 show the significant differ-ence in the positions of mini-implants placed with AUSOM and traditional wire guides (P = .009).

Table 1 Failure and success rates of placed mini-implants

AUSOM Wire guide Total

n (%) n (%) n (%)

Failures 1 (5.0) 5 (25.0) 6 (15.0)

Successes 19 (95.0) 15 (75.0) 34 (85.0)

Total 20 (100.0) 20 (100.0) 40 (100.0)

Table 2 Comparison between mini-implant placement method according to failure rate based on Wilcoxon signed rank test

nMean rank

Sum of ranks Z P

Negative ranks wire guide failure < AUSOM failure

4 2.50 10.00 –2.000(a) .046

Positive ranks wire guide failure > AUSOM failure

0 0.00 0.00

Ties wire guide failure = AUSOM failure

16

(a), based on postive rank.



DISCUSSION

All metallic and surgical wires guides need to be individually fabricated for every patient. All surgical templates have the same disadvantages; fabrica-tion is complicated and time-consuming, requires laboratory equipment, and is expensive. Moreover, such devices do not allow the orthodontist to perform the clinical adjustments. Wire guides do not prevent deviation of the pilot drill.

Using a tube in the Suzuki 3D guide with an internal diameter of 3 mm allows drill deviation; it is also limited to three lengths and is difficult to adjust in the anterior-posterior or vertical angulations necessary for optimal implantation.

The radiographic surgical guide orients both the radiographic and surgical procedures to ensure a coincident path for the x-ray and drill, which minimizes the risk of damage to anatomical structures, and can be used for predrilled implants.

The AUSOM may have several advantages. One, it works as a radiographic locator as well as a 3D surgical placement guide for mini-implants. Since it is a 3D adjustable guide, it can determine the point of implant insertion. The AUSOM’s simple design (Fig 2) is easy to use. Its design allows easy and rapid attachment at any position along a maxillary or mandibular archwire, with ei-ther labial or lingual appliances. It saves time; there is no need to repeat ra-diographs to determe if the new position is acceptable. It is less expensive: There is no need for laboratory fabrication, and it can be reused after steriliza-tion. The AUSOM can be used with self-drilling and predrilling mini-implants. Patient discomfort is minimal, and the guide can easily be removed from the archwire after mini-implant placement and reused on the opposite side, saving chair time and expense.

“”

The radiographic surgical guide orients both the radiographic and surgical procedures to ensure a coincident path for the x-ray and drill, which minimizes the risk of damage to anatomical structures …

Table 3 Mini-implant position in periapical radiographs

AUSOM (n = 20) Wire guide (n = 20) Total (n = 40)

n (%) n (%) n (%)

Not acceptable 1 (5.0) 5 (25.0) 6 (15.0)

Acceptable 2 (10.0) 6 (30.0) 8 (20.0)

Good 9 (45.0) 6 (30.0) 15 (40.0)

Very good 8 (40.0) 3 (15.0) 11 (27.5)

Table 4 Comparison between mini-implant placement method according to periapical radiograph results based on Wilcoxon signed rank test

nMean rank

Sum of ranks Z P

Negative ranks wire guide < AUSOM

15 9.53 143.00 –2.600(a) .009

Positive ranks wire guide failure > AUSOM failure

3 9.33 28.00

Ties wire guide failure = AUSOM failure

2

(a), based on postive rank.



35

Fig 2 Clinical procedures with AUSOM for mini-implant placement in the maxilla. (a) Putting AUSOM in the position thought to be suitable for mini-implant placement between the second premolar and first molar. AUSOM was fixed in place by a 0.16 × 0.22-inch archwire attached to the fixed appliance. (b and c) Applying the film-holding part after inserting film into the film holder. (d) Taking a periapical radiograph of the region. (e) Periapical radiograph with AUSOM showing that adjustments should be made (distalization of 1 mm and mesial palatal rotation of the placement guide). (f and g) Inserting the mini-implant into the interradicular septum via the placement guide cylinder. (h) Removing the archwire and AUSOM. (i and j) Mini-implant in place. (k) Periapical radiograph of the region after mini-implant insertion showing mini-implant was inserted perfectly. (l) Pre- and postinsertion radiographs.

a

d

g

c

f

i

k

b

e

h

j

l



CONClUSION

After using AUSOM on several patients and evaluating its efficiency, we find it to be a reasonable and practical method to guide and place mini-implants. The failure rate of mini-implants placed by AUSOM was lower than those placed by simple metallic guides. Clinical randomized studies must be carried out to prove AUSOM’s role in improving the success rate of mini-implant placement.

ACKNOWlEDGMENT

The device described in this article (AUSOM) received a national patent license with the follow-ing patent number, 1393, which was registered by INPI (National Institute for Industrial Property) in the Syrian Arab Republic.

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20. Chung KR, Nelson G, Kim SH, Kook YA. Severe bidentoalveolar protrusion treated with orthodontic microimplant-dependent en-masse retraction. Am J Orthod Dento-facial Orthop 2007;132:105–115.

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37

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25. Kim JW, Ahn SJ, Chang YI. Histomorpho-metric and mechanical analyses of the drill-free screw as orthodontic anchorage. Am J Orthod Dentofacial Orthop 2005; 128:190–194.

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33. Estelita Cavalcante Barros S, Janson G, Chiqueto K, de Freitas MR, Henriques JF, Pinzan A. A three-dimensional radiograph-ic-surgical guide for mini-implant place-ment. J Clin Orthod 2006;40:548–554.

34. Suzuki EY, Suzuki B. Accuracy of miniscrew implant placement with a 3-dimensional surgical guide. J Oral Maxillofac Surg 2008;66:1245–1252.

35. Kim SH, Choi YS, Hwang EH, Chung KR, Kook YA, Nelson G. Surgical position-ing of orthodontic mini-implants with guides fabricated on models replicated with cone-beam computed tomogra-phy. Am J Orthod Dentofacial Orthop 2007;131(suppl):S82–89.

36. Kitai N, Yasuda Y, Takada K. A stent fabricated on a selectively colored stereolithographic model for placement of orthodontic mini-implants. Int J Adult Orthodon Orthognath Surg 2002;17: 264–266.

37. Viwattanatipa N, Thanakitcharu S, Uttr-aravichien A, Pitiphat W. Survival analyses of surgical miniscrews as orthodontic anchorage. Am J Orthod Dentofacial Orthop 2009;136:29–36.

38. Wu JC, Huang JN, Zhao SF, Xu XJ, Xie ZJ. Radiographic and surgical template for placement of orthodontic microim-plants in interradicular areas: A techni-cal note. Int J Oral Maxillofac Implants 2006;21:629–634.

39. Asscherickx K, Vannet BV, Wehrbein H, Sabzevar MM. Root repair after injury from mini-screw. Clin Oral Implants Res 2005;16:575–578.

40. Roberts WE, Helm FR, Marshall KJ, Gon-gloff RK. Rigid endosseous implants for orthodontic and orthopedic anchorage. Angle Orthod 1989;59:247–256.

41. Melsen B, Verna C. Miniscrew implants: The Aarhus anchorage system. Semin Orthod 2005;11:24–31.

42. Kravitz ND, Kusnoto B. Risks and complications of orthodontic minis-crews. Am J Orthod Dentofacial Orthop 2007;131(suppl):S43–S51.

43. Choi HJ, Kim TW, Kim HW. A precise wire guide for positioning interradicular miniscrews. J Clin Orthod 2007;41:258–261.

44. Bae SM, Park HS, Kyung HM, Kwon OW, Sung JH. Clinical application of micro-implant anchorage. J Clin Orthod 2002; 36:298–302.

45. Suzuki EY, Buranastidporn B. An adjust-able surgical guide for miniscrew place-ment. J Clin Orthod 2005;39:588–590.

46. Suzuki EY, Suzuki B. A simple three-di-mensional guide for safe miniscrew place-ment. J Clin Orthod 2007;41:342–346.

Controversy

ORTHODONTICS The Art and Practice of Dentofacial Enhancement38

1 Former Resident, Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA; currently, Private Practice, Chicago, Illinois, USA.

2 Assistant Professor, Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.

3 Associate Professor, Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.

4 Professor and Head, Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.

5 Assistant Professor, Department of Oral Medicine and Diagnostic Sciences, University of Illinois at Chicago, Chicago, Illinois, USA.

6 Clinical Professor, Department of Orthodontics, University of Illinois at Chicago, Chicago, Illinois, USA.

CORRESPONDENCE Dr Maria Therese S. Galang Department of Orthodontics University of Illinois at Chicago 801 S Paulina St, Room 131 M/C 841 Chicago, IL 60612 Email: [email protected]

Phantom bite: A survey of US orthodontists

Bozena B. Ligas, DMD, MS1

Maria Therese S. Galang, DMD, MS2

Ellen A. BeGole, PhD3

Carla A. Evans, DDS, DMSc4

Gary D. Klasser, DMD5

Charles S. Greene, DDS6

Aim: In 1976, Marbach described the term phantom bite as a patient’s perception of an irregular bite when the clinician could identify no evidence of a discrepancy. Typically, the patient presents with a history of bite-altering procedures, hyperawareness of occlusion, and a persistent complaint of an uncomfortable bite, usually with an absence of pain. Patients with phantom bite complaints often undergo lengthy, expensive, irreversible, invasive, and unnecessary treatments in search of a resolution of their symptoms. The objectives of the study were: (1) to gauge orthodontists’ awareness of phantom bite and its associated signs and symptoms, (2) to identify the most common types of treatments rendered for this phenomenon, (3) to determine if regional differences or length of practice experience affected the aforementioned factors, and (4) to determine sex characteristics of patients with phantom bite. Methods: The study consisted of a 14-item survey administered electronically using SurveyMonkey software. Using the American Association of Orthodontists (AAO) directory, 4,124 orthodontists were recruited to participate via email; 337 completed the survey. Results: Approximately 50% of the responding orthodontists were unfamiliar with the term “phantom bite”; however, many reported seeing patients with phantom bite complaints. Demographic differences, such as geographic region of practice or years in practice, did not affect familiarity with this condition or its treatment. Conclusion: The results suggest a need for increasing awareness of this condition among orthodontic practitioners to provide patients with appropriate care. ORTHO 2011;12:38–47.

Key words: phantom bite, occlusion, occlusal dysthesia, occlusal hyperawareness

Dentists often encounter patients who have unusual oral complaints that do not fit into ordinary and customary categories (ie, toothache, gingival bleeding, or oral sores). One particular phenomenon in den-

tistry, commonly referred to as phantom bite, exemplifies this type of clinical problem. Patients may present with a variety of subjective occlusion-related complaints; upon examination, however, the dentist can find no evidence of a problem. Most often, the patients verbalize that their bite is off, meaning that it is uncomfortable or abnormal in some way.1,2 They are extremely preoc-cupied and focused with how their teeth come together, appearing virtually

39Volume 12, Number 1, 2011Volume 12, Number 1, 2011 39

obsessed. The onset of such complaints almost always begins after some type of bite-changing procedure involving major dental restorations or orthodon-tic treatment has occurred. Over time, it could become a chronic condition. These patients often travel from clinician to clinician in search of a “cure,” acquiring along the way treatments ranging from removable splints and oc-clusal equilibration to orthodontic therapy and complete full-mouth prosthetic reconstruction, none of which provide relief or satisfaction.

Since orthodontists routinely perform treatment that alters the occlusion, at some point in their careers, they may encounter patients with phantom bite com-plaints. When general dentists are faced with the dilemma of a patient seeking treatment for such a problem, they frequently refer patients to a specialist. Or-thodontists, being specialists in managing occlusal relationships, will therefore be likely to have these patients referred to them. Alternatively, some patients may identify orthodontists as specialists from whom to seek help. The orthodon-tist’s own patients may develop this problem as well, since they are undergoing major bite-changing treatment. Early identification of such patients is vital be-cause it will minimize the patients’ frustration and anxiety over the condition as well as the likelihood of unnecessary, time-consuming, and costly treament.

The purpose of this survey study was to determine whether US orthodontists were aware of the existence of phantom bite, and if so, how they dealt with the patients who presented with such problems. To get a more complete picture, orthodontists were also asked how frequently they saw patients with the typi-cal complaints of this condition, even if they did not label it as such. Another goal was to identify the most common types of treatments rendered by ortho-dontists for this phenomenon as well as to determine if regional differences or length of practice experience affected their approach to those patients. In ad-dition, this study aimed to determine the sex distribution of patients who pre-sented to orthodontists with phantom bite. The authors did not try to ascertain the prevalence of phantom bite among the general population, because that would require a systematic epidemiologic approach.

Etiologic theories for phantom bite A psychologic disorder. The term “phantom bite” was coined by Dr Joseph Marbach in 1976.1 At that time, Marbach proposed that this was a psycho-logic condition, comparing patients with phantom bite complaints to paranoid schizophrenics with obsessive-compulsive tendencies. He described the typi-cal manifestation of this condition beginning in late adolescence, commonly following orthodontic treatment. Although orthodontic changes normally occur slowly, allowing most patients to adapt over time, Marbach believed some patients fail to do so, and for them, the treatment could become a “catalyst . . . in the nascent schizophrenic.” The initial sign is the development of a preoc-cupation with the details of treatment. Marbach explained that these patients experience proprioceptive changes in their occlusion at the conscious level and begin a quest to collect dental casts, radiographs, and treatment notes

abnormalobsessedcomplaintsanxiety

frustrationawareness

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Phantom bite: A survey of US orthodontistsControversy


in an attempt to remember their original occlusion. These patients will often invest much time, money, and energy traveling from clinician to clinician with these items and requesting treatment that will allow them to regain their origi-nal bite. Over time, the recollection of their original bite often becomes very distorted and unreasonable. Marbach noted that there was neither a way to screen for the potential for this problem, nor any method to prevent it. He also believed that once the problem is observed, a psychiatric referral should be made. No tooth-altering treatment should be rendered; in fact, he suggested the best treatment was no treatment at all.1

In later publications, Marbach et al3 and Marbach4 altered the classification of phantom bite as possibly falling under the category of monosymptomatic hypochondriacal psychosis, defined by Munro5 as having an unshakeable belief in a distorted body image (as with anorexia nervosa patients). A second possi-ble label Marbach proposed was dysmorphophobia, which is when the patient has a delusion about a cosmetic defect. Both of these classifications still regard phantom bite as a psychologic disorder, and the authors’ recommendation for treatment remained unchanged.

A nervous system disorder. Melzack discussed brain signaling and the neuro-matrix theory, stating that physical sensations can be felt without actual input from the body.6 They are generated by the brain, and although peripheral stim-uli almost always precede the sensations, they do not directly produce them.

As research grew on the topic of phantom limb pain, discussions about phantom bite began appearing in this category. Marbach7 published an article on three types of orofacial phantom phenomena: phantom tooth pain follow-ing extraction or root canal therapy, stump pain in the edentulous patient, and phantom bite. Although Marbach admits that patients exhibiting symptoms of phantom bite rarely complain of any pain, he advocates that the pathophysi-ology of this altered perception may be similar to that of the phantom limb phenomenon, in which the patients’ painful symptoms appear to be due to changes not only in the peripheral nervous system but also the central nervous system. There may be neuroma formation or nociceptor sensitization in the peripheral area, in addition to processing changes in the brain regarding how the input signals are now processed, interpreted, and stored.6

Another proposed physical etiology for phantom bite during this time hy-pothesized that the complaints generated by these patients were actually due to their preexisting heightened occlusal awareness. Baba et al8 tested this the-ory by comparing a group of phantom bite patients with a control group. Thick-ness discrimination and mouth opening reproducibility tests were administered to the two groups, but no significant differences were found. The authors con-cluded that these patients did not differ from healthy subjects in their sensory, perceptive, or discriminative abilities.

A combination disorder. In 1997, Clark et al9 noted that a more appropriate term for phantom bite would be occlusal dysesthesia (OD), meaning an altered or abnormal sensation in regard to the bite. In a later paper,10 Clark and Sim-mons suggested two possible explanations for this disorder: (1) an impaired “oral kinesthetic ability” that they define as a person’s ability to differentiate the position of the mandibular jaw; or (2) a psychiatric disorder, particularly somato-form disorder. These authors believe that a psychologic diagnosis should be considered only after all physical sources are ruled out. This article also attempt-ed to answer whether occlusal dysesthesia was linked to temporomandibular disorders (TMDs). The conclusions were that TMD changes of the involved joint and muscles could initiate OD, but that OD can indeed develop independently.9 Besides a psychiatric consultation, if warranted, they recommended the use of an occlusal splint, with gradual usage reduced over time as well as patient edu-cation as the treatment of choice.


Ligas et al Controversy

41

Phantom bite patients referred for a psychologic evaluation may be diag-nosed with comorbid depression, obsessive-compulsive tendencies, or somato-form disorder. Somatoform disorder inclusion criteria, as listed by the Diagnostic and Statistical Manual of Mental Disorders IV,11 consist of one or more physical complaints that cannot be fully explained by a medical condition. They cause clinically significant distress with a duration of at least 6 months and are not part of another mental disorder or intentionally produced. The medical expenses of these patients are estimated to be six to 14 times higher than average and have negative effects due to lost work and productivity.12,13

Reeves and Merrill14 noted that it is imperative for dentists to consult psy-chologists upon observing this disorder, so that cognitive-behavioral therapy may be initiated. This therapy includes education, relaxation and stretching ex-ercises, positive feedback, and possibly psychopharmacologic management. Treatment could be rendered by any dentist or psychologist familiar with this condition and its course of treatment. These authors believe that continued dental treatment will not only fail in relieving the patients’ symptoms, but also likely make the problem worse. Further dental treatment or even a referral to another dental specialist for a second opinion will only reinforce the patients’ “illness conviction” and raise their preoccupation with their symptoms.

Etiology conclusions. The most likely conclusion that can be drawn from the current literature suggests that phantom bite has neurologic and psychologic eti-ologic components. Therefore, clinicians should appreciate that patients with this condition are experiencing a combination of neurosensory hyperawareness and psychologic impact. Because these patients can present to both general dentists and specialists, all dentists should be educated about this diagnosis, not only so that reasonable advice and treatment can be given, but also to minimize the distress experienced by both the patient and clinician rendering treatment.

METHODS

This study was based on a 14-item questionnaire directed at practicing ortho-dontists. To the authors’ knowledge, no other similar study has been reported; therefore, a new set of questions was formulated based upon the expertise of the investigators. The survey questions were meant to determine whether US or-thodontists are aware of phantom bite, what common signs and symptoms of phantom bite they are encountering in their practices, how many of these types of cases they have encountered, and what types of treatment they are providing. The survey also included demographic questions for orthodontists, such as the state in which they practice and how many years they have been practicing ortho-dontics. The final question allowed for an open-ended comment on the subject.

The study sample consisted of licensed US orthodontists whose email ad-dresses were collected from every other page of the 2005 American Association of Orthodontists (AAO) directory. Duplicate email addresses were discarded; 4,124 usable email addresses were obtained.

The software used to design the survey and collect the responses was Survey-Monkey (SurveyMonkey.com). Using this software, a link to the survey webpage was created and emailed to the participants. Recipients were given 2 weeks to complete the survey. After the initial data-collection period, two reminder emails were sent, at 2-week intervals. SurveyMonkey sent the reminder emails only to those who had not responded at the 2-week time point. Data collection was complete 6 weeks after the initial survey was distributed.

After the initial 4,124 emails were sent, 899 failed to be delivered due to in-valid addresses. Forty-eight orthodontists replied via email that they could not take the survey because they were retired. Twenty-six participants chose to opt

“”

. . . clinicians should appreciate that patients with this condition are experiencing a combination of neurosensory hyperawareness and psychologic impact.




out, removing their email address from any further correspondence, and 2,814 failed to respond. In the end, 337 responses were collected, which represents 10.61% of possible respondents (Fig 1).

RESULTS

The answers to the first survey question revealed that 50.3% of the respon-dents were familiar with the term “phantom bite.” The second question in-vestigated the signs and symptoms associated with phantom bite. More than 75% of the respondents encountered one or more patients with the following symptoms or complaints: (1) excessive bite concerns; (2) statements such as “my bite is off” or “I lost my bite and am unable to find it” as a consequence of previous dental procedures; (3) detailed accounts of previous dental experi-ences, often expressing dissatisfaction; (4) complaints of bite irregularity not present upon careful examination; (5) unrealistic and excessive awareness of minute tooth alignment details and how they affect occlusion; and (6) history of various bite-altering procedures such as occlusal equilibration, multiple res-torations, or repeated orthodontic treatments. More than 50% of respondents had encountered patients who brought duplicate dental records from previous dentists as well as previously prescribed oral appliances; most of these patients reported an absence of pain but a persistent chief complaint of discomfort due to the bite. Finally, 36% of respondents saw patients who presented diagnostic casts with explanations regarding occlusal conditions.

Eighty-five percent of the respondents reported that these patients were pre-dominantly female. The number of years the respondents have been practicing orthodontics ranged from 1 to 60 years. The majority of respondents reported not holding a faculty position in an orthodontic residency program; 70 (21.3%) of the 329 who answered the question confirmed having faculty status. From those who identified themselves as faculty members, 75% reported seeing these phantom bite patients mostly in private practice.

The highest numbers of surveys were collected from respondents in the west-ern and southern regions of the United States, while the fewest were collected from the northeast region. A Pearson chi-square test found no statistically signifi-cant relationships between familiarity with the term phantom bite and the four US

Fig 1 Survey response flow chart.

3,177Possible respondents

4,124Email addresses

26Opted out (0.01%)

899Invalid addresses

337Completed survey (10.61%)

48Responded as retired

2,814No response (88.57%)



43

regions. Figure 2 displays the distribution of respondents who were familiar with the term vs those who were not. The Pearson chi-square test found no statistically significant relationships between respondents’ familiarity with the term phantom bite and their time in practice. Figure 3 displays the distribution of respondents familiar with the term vs those who were not, according to years in practice.

Due to the low number of respondents in each answer category of question 7, which was an eight-part question dealing with different management approach-es for phantom bite patients, the responses were pooled to obtain a larger num-ber of responses per answer category. For each treatment rendered, the always, almost always, and sometimes responses were grouped into a yes category; like-wise, the never and almost never responses were grouped into a no category. Table 1 shows the pooled responses for question 7. A majority of respondents answered yes to referred to another specialist; sent back to the referring doctor; and started orthodontic treatment. However, a majority answered no to referred to a prosthodontist; referred to another orthodontist; referred for psychologic evaluation; and mounted models, did occlusal analysis, and started orthodontic treatment. The Pearson chi-square test was completed to establish relationships between each of the seven treatments with the region of practice. No statistically significant relationships were found between the respondents in the four US re-gions and the treatment rendered.

Only 3% of the respondent orthodontists reported always resolving the case suc-cessfully. Fifty-two percent reported sometimes, and another 3% reported never resolving the patient’s chief complaint. Eighty-five percent claimed that no reading material or published literature was helpful in diagnosing or treating these patients.

DISCUSSION

Survey sampleIn general, response rates to emailed surveys have been steadily declining from a high at 61.5% in 1986 to 24.0% in 2000.15 Some of the reasons for this are an increase in unsolicited emails, email filtering, and the threat of viruses. In spite of the drawbacks of email surveys, this method is still a valuable re-search tool due to the many benefits, including speed and cost efficiency. Using an email survey is fast and relatively easy, therefore making it a valuable

Fig 3 Distribution of famil-iarity with the term “phantom bite“ according to years in practice.

Fig 2 Distribution of familiarity with the term “phantom bite” according to US region.

No.

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pilot study instrument to obtain baseline data for further investigation if the results indicate a need for subsequent research.

It is important to keep the relatively low response rate in mind when at-tempting to interpret the results of this survey. In addition, because the email addresses were taken from every other page of the AAO directory, this survey included participants from every US state. Therefore, when looking at the re-spondent demographics, particularly the uneven distribution across the four US regions, it may be explained by the fact that an uneven number of partici-pants were contacted in each region.

Familiarity with phantom bite Marbach4 stated, “The best approach to the care and treatment of the patient with phantom bite lies in the dentist’s familiarity with the signs and symptoms of these syndromes.” The current study indicates that approximately half the ortho-dontists who responded to this survey were not familiar with this condition. This may be an underestimate of the actual percentage for several reasons. One is that the survey questions exclusively used the term “phantom bite,” while other synon-ymous terms such as “occlusal dysesthesia,” “persistent uncomfortable bite,” or “occlusal neurosis” are frequently used in the dental literature. Although the invita-tion email did include these terms, participants who did not read it prior to starting the survey may have answered no to being familiar with the term “phantom bite,” whereas they may have been familiar with one of the abovementioned terms.

Alternatively, this percentage may be an overestimate of the actual familiar-ity rate. As with any survey study, the ultimate sample selection is not random because each respondent self-selects whether to participate. Several studies on survey research report that topic salience is a key factor influencing re-sponse rate.16,17 It is understandable that someone who regards a subject as meaningful and significant is more likely to participate in sharing opinions and experience. It follows that an orthodontist familiar with phantom bite, particu-larly someone who has encountered the difficulty of treating a patient with this condition, would be more likely to complete the present survey than an ortho-dontist who is unaware of it. If the invitation specifically stated that the survey aimed to gauge orthodontists’ awareness of the subject, those unfamiliar with it may have been more likely to participate.

table 1 Management of patients presenting with symptoms related to phantom bite: Pooled responses for question 7 (“how did you manage the case/s that you did encounter?”)

Yes No Total count per question

Referred to a prosthodontist 107 129 236

Referred to another orthodontist 32 187 219

Referred for a psychologic evaluation 43 178 221

Referred to another specialist 187 53 240

Sent back to the referring doctor 166 70 236

Started orthodontic treatment 170 79 249

Mounted models, did occlusal analysis, then started orthodontic treatment

120 125 245

Other (please specify) 75

Answered question 289

Skipped question 48



45

Encounters with phantom bite complaintsAlthough approximately only half of the survey respondents reported being fa-miliar with the term “phantom bite,” a high percentage (86%) reported seeing one or more patients with unrealistic and excessive awareness of minute tooth alignment details and complaints about their occlusion. More than half of the respondents (60.6%) reported that during the time they have practiced ortho-dontics, they have encountered five or more of these types of patients; 21.2% indicated that they have seen 15 or more. Eighty-three percent have heard a patient state that her “bite is off” or “I lost my bite and am unable to find it” as a consequence of previous dental procedures. Seventy-five percent have had a patient complain of bite irregularity that was not visibly present upon careful examination. Sixty-three percent had a patient present without pain but with a persistent chief complaint of bite discomfort. The combination of low famil-iarity with the term phantom bite, yet relatively high occurrence of patients presenting with symptoms of the same, may indicate a potential problem with misdiagnosis and inappropriate treatment of these patients. This in turn would indicate a need for increasing awareness of this problem and how to manage it.

There was a wide range of answers to the question asking participants to quan-tify what percentage of patients who presented to them with such occlusal com-plaints would receive a phantom bite diagnosis. The answers ranged from 0% to 100%, with a large standard deviation of 33.8, suggesting that respondents are either using different criteria for this diagnosis or do not know what the criteria are.

The results suggest that there are no differences among orthodontists in fa-miliarity with phantom bite across the US regions, and this did not significantly vary from region to region. It also did not vary when comparing the respon-dents according to length of practice, meaning that those practicing for 10, 20, or 30 years were equally likely to be familiar with this condition. These results also indicate that there may be no differences in schools of thought in vari-ous areas of the country that would predispose certain graduates to be more aware of phantom bite. Furthermore, the results do not show that increased practice experience increases the likelihood of the orthodontist being familiar with this condition or that those who more recently completed a training pro-gram are more likely to recognize the term.

Treatment of phantom biteThe most recent literature describes phantom bite or occlusal dysesthesia as a form of somatoform disorder, for which the appropriate treatment is cognitive behavioral therapy. When the diagnosis is suspected, many experts suggest that a psychologic referral should be made.2,14 However, 80.5% of the respon-dents in this study reported never or almost never referring to a psychologist. When presented with a patient exhibiting signs and symptoms of phantom bite, 9.2% of responding orthodontists said they would always or almost al-ways start orthodontic treatment, while 59% said they sometimes do that; only 31.7% of the respondents said they would never or almost never start orth-odontic treatment. Attempting to treat these patients occlusally is contrary to every expert’s recommendations about how to deal with these hyperaware-ness complaints. The lack of psychologic consideration, combined with the willingness to treat these patients orthodontically, implies a need for educating orthodontic practitioners about this diagnosis.

Overwhelmingly, respondents to this survey stated that females (81.5%) were the predominant sex among patients who presented with signs and symptoms of phantom bite. This agrees with a study by Yamaguchi et al,18 in which their sample consisted of four males and 35 females. These authors retrospectively examined the features of patients with phantom bite, which they referred to as persistent uncomfortable occlusion, who presented to a Japanese clinic over a

“

”

The combination of low familiarity with the term “phantom bite,” yet relatively high occurrence of patients presenting with symptoms of the same, may indicate a potential problem with misdiagnosis and inappropriate treatment of these patients.




period of 4.5 years. Their data also showed that 22 (56.4%) of the 39 persistent uncomfortable occlusion patients did not improve with time or with various types of treatments.

In this study, however, only 15.1% of the respondents reported that the patient’s chief complaint was never or almost never resolved successfully. One possibility for this difference is that the sample populations are differ-ent, reflecting ethnic or cultural differences. Another possibility is that different criteria were used to diagnose persistent uncomfortable occlusion patients, resulting in different treatment success rates. In addition, the Japanese clinic specifically diagnosed and treated these patients, while the surveyed ortho-dontists were only randomly encountering them. Finally, the orthodontists in the present study may not have realized that some of their unimproved pa-tients simply sought treatment from another clinician with the same complaint, thereby inflating their perceived success rates.

It is noteworthy that 85.4% of the respondents stated that no reading material or published literature was helpful in diagnosing or treating these cases. This is not surprising, since the only published article in an orthodontic journal on the topic of phantom bite is Marbach’s 1976 paper in which he introduced the term.1 Of the more recently published articles that discuss the topic of phantom bite, three2,8,18 were in non-US journals, while only two10,14 were published in US-based dental journals. Hopefully, the current study may serve as an important stimulus for this discussion and for further research within the orthodontic community.

The most current literature on the subject describes a model that includes both neurologic and psychologic components of phantom bite. Reeves and Merrill14 provided a hypothesis for the etiology of this condition that combined occlusal hyperawareness in a patient prone to somatization. In such a case, mental and emotional stresses can manifest in the form of psychosomatic illnesses. Accord-ing to these authors, cognitive behavioral therapy is the appropriate treatment. They warn that continued dental therapy will most likely not improve the condi-tion, but may in fact worsen it by reinforcing the patients’ illness conviction and increasing their somatic preoccupation. Treatment should focus on patient edu-cation and improved overall well-being and functioning, rather than complete symptom eradication. One may draw a parallel to chronic pain patients when attempting to understand the interplay of neurologic and psychologic compo-nents involved in phantom bite. Also, clinicians can draw on current concepts of chronic pain treatment to understand why further dental manipulation of the phantom bite patient is not recommended. Failure to recognize this paradoxic situation may lead to lengthy, expensive, unnecessary, invasive, and unsuccessful mechanical treatment of these patients, resulting in frustration for both the pa-tient and the treating clinician as well as possible litigation. Therefore, awareness of this condition and its proper treatment is important.

Respondent commentsSeveral respondents said that they have “never read or heard of this condition” or were unaware “that anyone had put a ‘name’ on this problem.” Many com-ments suggested that dentists rarely see this condition: “It is a nonentity,” and “Your cause is of minor concern to most practitioners and patients.” Others re-lated in detail their encounters and frustrations with such patients and stated that “research addressing this issue is long overdue.” Comments on the treatment provided for these patients varied the most. Some orthodontists attempt to do as little as possible, choosing a noninvolvement approach, while others provide pa-tient education along with a lot of handholding. However, many said they strongly believe that there usually is an occlusal discrepancy and that proper diagnos-tic procedures (ie, articulator mountings or recognizing CR to CO discrepancies) will reveal the occlusal problem and point to the correct treatment. There were



47

also many comments that categorized this condition along with TMD and recom-mended the same approach to treating these patients as TMD patients. There did not appear to be any general consistency to the respondent comments, either in their level of understanding or in the treatment provided for these patients, sug-gesting a need for increasing orthodontists’ knowledge of phantom bite, how to diagnose it, and the appropriate treatment for this condition.

CONCLUSION

Approximately 50% of the orthodontists who responded to the survey were not familiar with the term “phantom bite,” although a majority reported encounter-ing patients with signs and symptoms of that condition. Most orthodontists do not even consider making a psychologic referral, and many start orthodontic treatment in an attempt to resolve these complaints. These factors, combined with the reported lack of literature on the subject, indicate a need for further re-search and education of orthodontists on this topic, so that they may themselves provide the appropriate advice and treatment or make the appropriate referral.

ACKNOWLEDGMENTS

The authors wish to thank Dr Nishant Patel and Dr Hoi-Jeong Lim for their assistance in data col-lection and statistical analysis, respectively.

“ ”. . . awareness of this condition and its proper treatment is important.

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2. Jagger RG, Korszun A. Phantom bite revisited. Br Dent J 2004;197:241–243.

3. Marbach JJ, Varoscak JR, Blank RT, Lund P. Phantom bite: Classification and treat-ment. J Prosthet Dent 1983;49:556–559.

4. Marbach JJ. Psychosocial factors for fail-ure to adapt to dental prostheses. Dent Clin North Am 1985;29:215–233.

5. Munro A. Monosymptomatic hypochon-driacal psychosis. Br J Hosp Med 1980; 24:34–38.

6. Melzack R. Pain: Past, present, and future. Can J Exp Psychol 1993;47:615–629.

7. Marbach JJ. Orofacial phantom pain: Theory and phenomenology. J Am Dent Assoc 1996;127:221–229.

8. Baba K, Aridome K, Haketa T, Kino K, Ohyama T. Sensory perceptive and dis-criminative abilities of patients with occlusal dysesthesia [in Japanese]. Nihon Hotetsu Shika Gakkai Zasshi 2005;49:599–607.

9. Clark G, Tsukiyama Y, Baba K, Simmons M. The validity and utility of disease de-tection methods and of occlusal therapy for temporomandibular disorders. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 1997;83:101–106.

10. Clark G, Simmons M. Occlusal dysesthesia and temporomandibular disorders: Is there a link? Alpha Omegan 2003;96:33–39.

11. American Psychiatric Association. Diag-nostic and Statistical Manual of Mental Disorders DSM-IV. New York: American Psychiatric Association, 1994.

12. Smith GR Jr, Monson RA, Ray DC. Psychiatric consultation in somatization disorder: A randomized controlled study. N Engl J Med 1986;314:1407–1413.

13. Katon W, Lin E, Von Korff M, Russo J, Lipscomb P, Bush T. Somatization: A spec-trum of severity. Am J Psychiatry 1991;148: 34–40.

14. Reeves JL II, Merrill RL. Diagnostic and treatment challenges in occlusal dysesthe-sia. J Calif Dent Assoc 2007;35:198–207.

15. Sheehan KB. E-mail survey response rates: A review. J Comput Mediat Com-mun [serial online] 2001;6(2). Available at: http://jcmc.indiana.edu/vol6/issue2 /sheehan.html. Accessed 9 February 2011.

16. Sheehan KB, McMillan SJ. Response varia-tion in e-mail surveys: An exploration. J Advert Res 1999;3:45-54.

17. Heberlein TA, Baumgartner R. Factors affecting response rates to mailed ques-tionnaires: A quantitative analysis of the published literature. Am Sociol Rev 1978; 43:447–462.

18. Yamaguchi T, Mikami S, Okada K, et al. A clinical study on persistent uncomfortable occlusion. Prosthodont Res Pract 2007;6: 173–180.

Interdisciplinary


A multidisciplinary approach to the treatment of a horizontally impacted mandibular second premolar: 10-year follow-up

Dror Aizenbud, DMD, MSc1

Liran Levin, DMD2

Shaul Lin, DMD3

Eli E. Machtei, DMD2

This report presents a multidisciplinary approach to the treatment of a rare case of a distally impacted mandibular second premolar indicating a 90-degree tilt of the long axis in a healthy, 15-year-old girl. It also describes the clinical and radiologic findings after a 10-year longitudinal follow-up period. The horizontally impacted mandibular second premolar was positioned behind the roots of the first molar and in close proximity to the root of the second molar, toward the lingual cortex of the mandibular body. Treatment methods required 2 years of cooperation among an orthodontist, an oral and maxillofacial surgeon, a periodontist, and an endodontist to achieve a leveled and aligned position in a properly healed condition. Finally, the horizontally impacted mandibular second premolar was correctly positioned in the arch surrounded by healed periodontal ligament tissue. Root resorption of the adjacent orthodontic anchorage units was recorded. The 10-year postoperative follow-up presented a stable, functional, and symptom-free permanent mandibular second premolar. The multidisciplinary dental team’s considerations and cooperation account for the successful repositioning of the compromised mandibular second premolar with minimal damage to the surrounding hard and soft tissue following 10 years of longitudinal follow-up. ORTHO 2011;12:48–59.

Key words: bone regeneration, combined lesion, endodontic treatment, impacted premolar, orthodontic traction, periodontal surgery

Impeded eruption or impaction of permanent teeth occurs in 5.6% to 18.8% of the population.1–4 The mandibular second premolar is typically among the last to develop and erupt, showing great variation in its development

pattern.5–12 It is therefore not surprising that impacted mandibular second premolars have been found to constitute approximately 24% of all impact-ed teeth, excluding third molars.13 Furthermore, the frequency of unerupted mandibular second premolars in 15-year-old children is as high as 9.7%.14

1 Orthodontics and Craniofacial Department, Graduate School of Dentistry, Rambam Health Care Campus and Bruce Rappaport Faculty of Medicine—Technion, Israel Institute of Technology, Haifa, Israel.

2 Department of Periodontology, Graduate School of Dentistry, Rambam Health Care Campus and Bruce Rappaport Faculty of Medicine—Technion, Israel Institute of Technology, Haifa, Israel.

3 Unit of Endodontics and Dental Trauma, Department of Oral and Dental Sciences, Graduate School of Dentistry, Rambam Health Care Campus and Bruce Rappaport Faculty of Medicine—Technion, Israel Institute of Technology, Haifa, Israel.

CORRESPONDENCE Dr Dror Aizenbud Orthodontic and Craniofacial Department Rambam Health Care Campus PO Box 9602 Haifa 31096 Israel Email: [email protected]


The germ of the mandibular second premolar is ideally positioned between the two roots of the primary second premolar.15 Normally, the path of erup-tion follows the resorption of the roots of the primary second molar, with no major deviations. However, abnormal tooth germ position and consequent deviated angular changes during tooth development and eruption seem to be frequent.16,17 Left untreated, the tooth will remain impacted,5,9,11,18–23 with the risk of damaging neighboring teeth and loss of arch integrity.24,25

Conservative management with exposure of the crown has been advocat-ed.12,22,26–28 The majority of reported cases involve distally impacted premo-lars in which the long axis of the teeth were inclined in such a way that favors spontaneous or minimally assisted eruption if exposed. Surgical exposure is unpredictable and best limited to cases with no more than a 45-degree tilt of the long axis from its normal position.22

This report presents the rare case of a distally impacted mandibular second premolar with a 90-degree angulation from the long axis in a healthy 15-year-old girl. This horizontally impacted mandibular second premolar was posi-tioned behind the roots of the fi rst molar and in close proximity to the root of the second molar, toward the lingual cortex of the mandibular body. The con-siderations and treatment approach of a multidisciplinary dental team involving the management of the complicated malposed tooth are discussed and the 10-year postoperative long-term clinical and radiologic fi ndings are described.

CASE REPORT

A 15-year-old girl was referred to our clinic by her family dentist due to the delayed eruption of her mandibular right second premolar and overretained primary mandibular right second premolar.

The patient had no relevant medical history. Upon clinical examination, all permanent teeth had erupted except for the mandibular right second premo-lar and all third molars. The primary mandibular right second premolar was still in place, and both arches were well aligned with a Class I canine and molar relationship (Figs 1a to 1c). A normal incisor relationship, including overjet

Treatment of a horizontally impacted mandibular second premolarInterdisciplinary


and overbite and a normal growth pattern of the skeletal jaws, was recorded (Fig 1d). Cephalometric (Fig 1d) and panoramic (Fig 1e) radiographs revealed that the mandibular right second premolar was horizontally orientated and impacted distally behind the roots of the first and second molars toward the compact lingual cortex of the right lingual border of the mandibular body. The upper border of the unerupted distoangular inclined premolar was level with the apices of the adjacent teeth, and the crown could be palpated from the lingual aspect of the vestibule.

The patient was further examined by a multidisciplinary team—an ortho-dontist, oral and maxillofacial surgeon, periodontist, endodontist, and pedo-dontist—at the Rambam Health Care Campus–Graduate School of Dentistry. Following clinical and radiographic examination, a conservative treatment plan consisting of extraction of the primary mandibular right second premolar and surgical exposure and orthodontic extrusion of the impacted tooth was out-lined for the patient and her parents.

Fig 1 Pretreatment clinical and radiographic records. (a) Intraoral frontal view, (b) intraoral right lateral view, (c) intraoral mandibular occlusal view, (d) pretreatment lateral cephalometric radio-graph, and (e) pretreatment panoramic radiograph.

a

c

b

e d


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A 0.022 × 0.025-inch preadjusted fixed orthodontic appliance was attached to the buccal aspects of the mandibular dentition immediately after extraction of the primary second premolar. A passive open-coil spring was placed on the labial archwire of the orthodontic appliance to maintain appropriate space for the permanent second premolar until it was moved into its proper place.

After 4 months of mandibular orthodontic leveling and alignment, surgical exposure was performed. The most superficial labial surface of the impacted mandibular second premolar’s clinical crown was minimally exposed at the lin-gual side of the mandible behind the distal root of the permanent mandibular right first molar. A lingual button was attached with a 0.012-inch soft ligature wire (Fig 2a), which was twisted lightly around the lingual button prior to the bonding procedure. The surgical flap was sutured back, leaving the free end of the ligature, which was rolled into a small pigtail loop, near the palatal mu-cosa. A 0.014-inch auxiliary traction spring26 was prepared and applied in a piggyback fashion over the main 0.017 × 0.025-inch stainless steel mandibu-lar archwire. It was activated by tying the auxiliary spring loop to the ligature pigtail loop with elastic thread (Figs 2a and 2b), thus exerting gentle traction forces on the unerupted mandibular right second premolar in the occlusal- lingual direction. In this manner, and as time passed, the loop of the spring auxiliary progressively moved farther from the occlusal surface and interfered with normal oral function. The patient needed to be seen at 2-week intervals to roll the 0.012-inch ligature pigtail around the spring auxiliary loop and again draw it closer to the lingual mucosa. This produced added activation and sup-plemented the range even farther. It also improved patient comfort. During the 14-month phase of orthodontic traction, the mandibular right second premolar moved from the roots of the first and second molars and lingually erupted into the oral cavity while the dominant direction of the force was vertical.

In its approach toward the mandibular dental arch, the tooth was still located too lingually to be directly tied to the base archwire presented in the brackets. Hence, the lingual button was replaced by an orthodontic bracket bonded in an ideal position onto the labial surface of the mandibular right second premolar. A 0.015-inch twist flex multistranded wire was then attached to the tooth in a piggy back fashion, replacing the auxiliary spring and exerting a dominant hori-zontal force in the buccal direction (Fig 2c). Later, when the long axis of the man-dibular right second premolar was better oriented, elastic thread was applied and tied to the mandibular archwire at the incisor site, enhancing the buccal di-rection of the force (Fig 2d). Lingual brackets were then attached to the man-dibular molars and premolars for final aligning and torquing. After 2 years of treatment, the mandibular right second premolar was properly leveled and aligned in the mandibular arch (Figs 3a to 3c). Nonetheless, a per fect Class I occlusal relationship had not yet been achieved, and the mandibular right sec-ond premolar was therefore apparent in tooth-to-tooth relationships. However, periapical radiographs taken at the time (Figs 4a and 4b) revealed an asymptom-atic periapical radiolucent lesion that had developed in the mandibular right second premolar as well as angular alveolar bone loss diagnosed as an infrabony defect. Following a negative pulp vitality test, root canal treatment was initiated. The canal was dressed with calcium hydroxide for 1 month. At that point, the decision was made to cease orthodontic treatment in an effort to prevent further damage of the mandibular right second premolar and its adjacent teeth. The fixed orthodontic appliance was removed, and a removable maxillary clear re-tainer was prepared in addition to a fixed orthodontic twist-flex retainer that was bonded to the lingual aspects of the mandibular canines and incisors. An addi-tional 0.017 × 0.025-inch stainless steel wire splint was bonded to the buccal and lingual crown surfaces of the mandibular right segment (molars and premolars) due to increased mobility of the mandibular right second premolar.

Interdisciplinary

“

”

Cephalometric and panoramic radiographs revealed that the mandibular right second premolar was horizontally orientated and impacted distally behind the roots of the first and second molars toward the compact lingual cortex of the right lingual border of the mandibular body.



Fig 2 Surgical orthodontic traction stages of the mandibular right second premolar. (a) Periapical radiograph taken immediately after surgical exposure, with the lingual button bonded and the spring auxiliary tied to the mandibular right second premolar; (b) 0.014-inch auxiliary traction spring applied in a piggyback fashion; (c) 0.015-inch twist flex multistranded wire attached to the mandibular right second premolar in a piggyback fashion, replacing the auxiliary spring; (d) elastic thread applied and tied to the mandibular archwire at the site of the incisors.

Fig 3 Mandibular right second premolar properly leveled and aligned in its correct position in the arch. (a) Intraoral frontal view, (b) intraoral right lateral view, (c) intraoral mandibular occlusal view.

a

cb

a

c

b

d

“ ”…the decision was made to cease orthodontic treatment in an effort to prevent further damage of the mandibular right second premolar and its adjacent teeth.


Aizenbud et al Interdisciplinary

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During the second appointment with the endodontist, following 1 month of root canal dressing with calcium hydroxide, the canal was sealed with gutta-percha and AH-26 (Dentsply) and the crown was filled with glass ionomer (Fig 4c). Eight months later, a follow-up radiograph showed partial resolution of the periapical lesion and some improvement in the infrabony defect (Fig 4d).

The periodontal evaluation of the defect revealed a pocket depth of 9 mm on the mesiobuccal and mesiolingual aspects of the mandibular right second pre-molar, indicating a regenerative approach. Full-thickness mucoperiostal flaps were raised and two- to three-walled infrabony defects 7 mm in depth were re-vealed on the mesial aspect of this tooth (Fig 5a). The roots were thoroughly planed and decalcified using 24% ethylenediaminetetraacetic acid (EDTA). Each defect was then filled with bone-derived xenograft (BDX) (Bio-Oss, Geistlich) (Fig 5b) and covered with resorbable collagen membrane (Bio-Gide, Geistlich), which was thoroughly adapted in the proximal area between the mandibular right first and second premolars (Fig 5c). The flaps were repositioned and adapt-ed to completely cover the membrane.

The healing process was uneventful, and the patient was put on a mainte-nance program that included scaling and deplaquing every 3 months. Periapi-cal radiographs taken 2 years later revealed bone fill in the infrabony defect on the mesial aspect of the mandibular right second premolar. Some of the BDX particles were still evident; however, the radiolucent lesion decreased and a narrow space of the periodontal ligament was evident through the newly re-stored alveolar bone (Fig 5d). The orthodontic stainless steel wire splint was then removed, as increased stability was recorded for the mandibular right second premolar. Root resorption of the adjacent orthodontic anchorage units (the mandibular right molars and first premolar) was diagnosed.

At the 10-year postoperative examination, the mandibular right second pre-molar was found to be stable, functional, and symptom-free (Fig 6).

Fig 4 Periapical radiographs of the mandibular right second premolar orthodontic traction. (a) Dur-ing traction, revealing loss of alveolar bone support; (b) radiolucent lesion detected when the tooth was in its final position; (c) root canal treatment performed and the crown filled with glass ionomer; (d) follow-up radiograph 8 months later showing partial resolution of the periapical lesion and some improvement in the infrabony defect.

a

c

b

d



DISCuSSION

The dental team had three treatment options: (1) a wait-and-see approach, (2) surgical exposure and orthodontic extrusion,17,22,23 and (3) extraction of the horizontally impacted mandibular right second premolar.29 Each of these treatment options had several disadvantages, thus none could be considered as having only advantages (Table 1).

The first treatment option considered the asymptomatic primary mandibu-lar right second premolar and the balanced occlusion, despite the overretained tooth, and no distinct functional or esthetic complaints from the patient or her parents as advantages. However, it was obvious that this treatment modality would postpone the prosthetic treatment plan, which would be required soon after exfoliation of the primary mandibular right second premolar. Complete resorption of its roots would have left the mandibular right second premolar impacted in the lingual portion of the right mandibular body. At the same time, the impacted second premolar could have caused damage to the nearby molar roots. Thus, the restorative option (Table 2) for the missing mandibular right sec-ond premolar would probably have been a fixed partial denture with the mandib-ular right first premolar and first molar serving as abutments and a pontic serving as the second premolar. With this option, the prognosis for completely healthy

Fig 5 (a) Full-thickness mucoperiostal flaps and two- to three-walled infrabony defects 7-mm deep on the mesial aspect of this tooth. (b) The roots thoroughly planed and decalcified using EDTA 24%. The defect filled with bone-derived xenograft and (c) covered with resorbable collagen membrane (Bio-Gide) thoroughly adapted in the proximal area between the mandibular right first and second premolar. (d) Periapical radiograph taken 2 years later revealed bone fill in the infrabony defect on the mesial aspect of the mandibular right second premolar. Some of the BDX particles are still evident; however, the radiolucent lesion decreased and a narrow space of the periodontal ligament is evident through the newly restored alveolar bone.

a

c

b

d



55

abutment teeth would be slim. Removable partial dentures are not applicable for young patients. Dental implants would have been impossible in light of the mandibular right second premolar’s unusually long horizontal axis, which would have served as an obstacle. Thus, with this scenario, extraction of the mandibular right second premolar would have required dental implantation. Surgical extrac-tion of the mandibular right second premolar was not free of complication or risk.

The second option included surgical exposure and bonding for orthodontic traction. This type of treatment can be technically demanding since it compro-mises the position of the mandibular right second premolar. According to the lit-erature, extreme cases do not respond well to exposure.23 Becker discussed two cases of surgical exposure followed by bonding of an attachment for traction.17 One of these cases was a failed attempt of bonding and traction, underscoring the difficulty of access for the bonding approach. Andreassen illustrated suc-cessful and unsuccessful cases of exposure of horizontally inclined premolars.22 The majority of reported cases involved distally impacted premolars in which the long axis was inclined to favor eruption if exposed.12,22,30–32 Jacobs documented six cases of successful exposure and eruption.31 In all six cases, the axial root inclination favored eruption. Forty-five degrees from the normal eruptive posi-tion has been considered the limit at which spontaneous eruption is no longer

Fig 6 Periapical radiographs of the mandibular right second premolar taken at the 10-year post-operative examination. The permanent mandibular right second premolar is stable, functional, and symptom-free.

Table 1 Treatment options and procedures

Treatment Advantages Disadvantages

Wait-and-see approach • Conservative approach• Balanced occlusion• No functional or esthetic

complaints

• Chronologic age of the patient (15 years) with mandibular right second premolar roots already completed and complete resorption of primary mandibular right second premolar roots

• Postponed prosthetic treatment• Impacted mandibular right second premolar may damage

molar roots

Surgical exposure and bonding for orthodontic traction

• Restore the unerupted mandibular right second pre-molar with the natural tooth itself

• Requires risky surgical exposure• Compromised mandibular right second premolar position

resulted in technical demands of bonding and orthodontic traction

• Extreme cases are best not to expose

Surgical extraction • Prevents prolonged, risky, compromising, and unpredictable surgical exposure and orthodontic treatment procedure

• Limited surgical approach• Excessive damage to hard and soft tissue, nerve tissue, and

teeth• Risk of infection• Loss of alveolar bone mass for future implantation

“”

Each of these treatment options had several disadvantages, thus none could be considered as having only advantages.



possible.22,30 In our case, the impacted mandibular right second premolar’s long axis presented an inclination of 90 degrees from the normal eruptive position.

The third treatment option included surgical extraction of the impacted premolar. This involved even more complications and risks compared to the second option of surgical exposure limited to the tooth bud. Complications include mental nerve damage; mucosal trauma; infection; damage to the sur-rounding teeth; and periodontal, restorative, and orthodontic difficulties cre-ated by extensive bone removal with subsequent loss of alveolar bone height and contour.33,34 Furthermore, since the impacted mandibular right second premolar was lingually palpated and oriented deep in the lingual vestibulum, the surgical approach would have been limited and compromised. There-fore, lingual nerve injury is also a possible adverse effect that must be con-sidered.35,36 The compromised approach and location of the mandibular right second premolar (which was in close proximity to and behind the first and second molar roots) might have caused damage to the roots during surgical extraction with massive loss of bone attachment. Ultimately, this could have resulted in loss of the first and second molars.

The second option of orthodontic maneuver was considered the treatment of choice for this challenging mandibular right second premolar. It could have brought about speedy and effective eruption and moved the mandibular right second premolar from the roots of the mandibular molars. Since adequate space was already available in the arch as a result of the retained primary mandibular right second premolar, a minimal leveling procedure was required before surgical exposure and extrusion of the permanent mandibular right second premolar began. An occlusally directed vector of traction may have brought the mandibular right second premolar into contact with the molar roots, which would have damaged them. Accordingly, the method used in this case was to first move the impacted mandibular right second premolar in an occlusal (vertical download) and lingual direction to circumvent the obstacle in its path and only then move it bucally toward its final location. A spring auxil-iary26 incorporating a single vertical loop with a small helix at its extremity was used. This device was modified by making the vertical loop longer, thus intro-ducing a more horizontal than vertical traction vector. This was done to move the impacted mandibular right second premolar more lingually (toward the midline) while the spring was drawn inferiorly. Though the dominant direction of movement was vertical, the tooth moved noticeably away (and became dis-

Table 2 Prosthetic treatment options available for the unerupted mandibular right second premolar

Treatment Advantages Disadvantages

Fixed partial denture • Leave impacted mandibular right second premolar in place, thus preventing surgical procedure

• Restore esthetics and function with relative minimal damage to periodontal and dental tissue

• Risk of severely compromising completely healthy abutment teeth

Removable partial denture

• Restore esthetics and function with minimal damage to dental tissue

• Is not applicable for a young patient• Potential damage to periodontal tissue with

long-term use

Dental implant • Minimal damage to surrounding dental and periodontal tissue

• Impacted mandibular right second premolar serves as an obstacle, and a surgical procedure for its extraction is required for dental implantation



57

impacted) from the roots of the molars. The activation of the spring produced a very wide range of actions, and even the most deeply buried portions of the tooth responded to the force applied. However, it is important that undue force be avoided, since in the event of excessive forces, the socket walls would resist by producing undermining resorption.37 On the other hand, extrusion is the only orthodontic movement in which the walls of the tooth socket do not provide some form of protection against heavy pressure. Consequently, reduced forces should be applied. A force of 24 cN per cm2 of root surface is generally considered optimal for tipping a tooth.38,39 We can conclude that force levels of less than 24 cN should be used when pure extrusive force is ap-plied through the long axis of an erupted tooth.26 In this case, where the tooth was completely buried, soft tissue resistance increased the amount of force needed, but did not exceed 30 to 35 cN.26

The presented method describes the ability to apply measured forces in oc-clusal, lingual, and anterior directions, which allowed complete control to be exercised in the efficient resolution of the impaction.

Even successfully aligned teeth can have dwarfed roots, pulpal obliteration, and nonvitality,29 which in turn requires root canal therapy and restoration. Excessive tooth movement increases the risk of pulpal changes, with pulpal obliteration occurring in more than 20% of previously impacted canines.40 Ex-perimental studies have suggested that extreme types of tooth movement may cause changes in pulpal blood flow.41–43 The periodontal ligament and root canal systems have a common developmental, anatomical, and functional rela-tionship.44–50 Theoretically, changes in one tissue affect the other and are con-nected both anatomically and physiologically. The main connection between the periodontal support system and the root canal through which bacteria and their products pass and cause pathology is the apical foramen. The major pas-sage is from the root canal to the periapical tissue, which leads to a local inflam-matory response that manifests in the bone or in root absorption.51

In this case, the orthodontic treatment was terminated before final torque and perfect occlusion of the mandibular right second premolar was achieved. The apparent periodontal-endodontic lesion that developed around the man-dibular right second premolar root seemed to cause root resorption and en-danger the adjacent permanent roots. According to the literature, cessation of orthodontic treatment was indicated: The final occlusion should be compro-mised to prevent further worsening of the patient's teeth.52

Maintaining adequate plaque control around the lingually exposed man-dibular right second premolar may be difficult due to the combination of its compromised position and irritation from orthodontic attachments. Therefore, surgical exposure and orthodontic alignment of palatally impacted canines is associated with a loss of periodontal support.53–55 Furthermore, Becker et al claimed that more profound periodontal consequences may reflect a more aggressive surgical exposure.56 The loss of periodontal attachment was associ-ated with pocket formation rather than recession of the gingival margin.57 The adjacent teeth, serving as anchorage units, are exposed to intrusive forces and root torque during the alignment of the impacted mandibular right second premolar. An association has been found between root shortening and tooth intrusion.57,58 Linge and Linge59 reported that alignment of impacted maxillary canines is a risk factor for root resorption. However, longitudinal clinical and radiologic follow-up along the 10-year follow-up period demonstrated that the permanent mandibular right second premolar is stable with no additional splinting required, functions normally, and is symptom-free. This may be attrib-uted to the conservative, minimally invasive treatment method chosen for such a complex case and the reduced orthodontic forces that were applied during the traction of the impacted mandibular right second premolar.

“

”

The presented method describes the ability to apply measured forces in occlusal, lingual, and anterior directions, which allowed complete control to be exercised in the efficient resolution of the impaction.



CONCluSION

This report presents a rare case of a distally impacted mandibular second pre-molar indicating a 90-degree tilt of the long axis. This horizontally impacted mandibular right second premolar was positioned in a very complicated and compromised position behind the molars' roots and in close proximity to the lingual and mental nerves, toward the lingual cortex of the mandibular body. The multidisciplinary dental team's considerations and cooperation account for the successful repositioning of the compromised mandibular right second premolar into its proper position with minimal damage to the surrounding hard and soft tissue. A 10-year postoperative follow-up showed that the mandibular right second premolar is stable, functional, and symptom-free.

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The multidisciplinary dental team’s considerations and cooperation account for the successful repositioning of the compromised mandibular right second premolar into its proper position with minimal damage to the surrounding hard and soft tissue.



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40. Woloshyn H, Artun J, Kennedy DB, Joondeph DR. Pulpal and periodontal reactions to orthodontic alignment of palatally impacted canines. Angle Orthod 1994;64:257–264.

41. Butcher EO, Taylor AC. The vascularity of the incisor pulp of the monkey and its alteration by tooth retraction. J Dent Res 1952;31:239–247.

42. Stenvik A. Pulp and dentine reactions to experimental tooth intrusion. (A histologic study—Long-term effects). Rep Congr Eur Orthod Soc 1969:449–464.

43. Marshall JA. A study of bone and tooth changes incident to experimental tooth movement and its application to orth-odontic practice. Int J Orthod Dent for Children 1933;19:1–17.]

44. Mandel E, Machtou P, Torabinejad M. Clinical diagnosis and treatment of endodontic and periodontal lesions. Quintes-sence Int 1993;24:135–139.

45. Orban B. Oral Histology and Embryology, ed 5. St Louis: Mosby, 1962.

46. De Deus QD. Frequency, location, and direction of the lateral, secondary, and ac-cessory canals. J Endod 1975;1:361–366.

47. Simon JH, Glick DH, Frank AL. The relationship of endodontic-periodontic lesions. J Periodontol 1972;43:202–208.

48. Baumgartner JC, Picket AB, Muller JT. Mi-croscopic examination of oral sinus tracts and their associated periapical lesions. J Endod 1984;10:146–152.

49. Langeland K, Rodrigues H, Dowden W. Periodontal disease, bacteria, and pulpal histopathology. Oral Surg Oral Med Oral Pathol 1974;37:257–270.

50. Meng HX. Periodontic-endodontic le-sions. Ann Periodontol 1999;4:84–90.

51. Rotstein I, Simon JH. Diagnosis, prognosis and decision-making in the treatment of combined periodontal-endodontic le-sions. Periodontol 2000 2004;34:165–203.

52. Brezniak N, Wasserstein A. Orthodontical-ly induced inflammatory root resorption. Part II: The clinical aspects. Angle Orthod 2002;72:180–184.

53. Hansson C, Linder-Aronson S. Gingival status after orthodontic treatment of im-pacted upper canines. Trans Eur Orthod Soc 1972:433–441.

54. Wisth PJ, Norderval K, Boe OE. Periodon-tal status of orthodontically treated im-pacted maxillary canines. Angle Orthod 1976;46:69–76.

55. Boyd RL. Clinical assessment of injuries in orthodontic movement of impacted teeth. I. Methods of attachment. Am J Orthod 1982;82:478–486.

56. Becker A, Kohavi D, Zilberman Y. Peri-odontal status following the alignment of palatally impacted canine teeth. Am J Orthod 1983;84:332–336.

57. McFadden WM, Engstrom C, Engstrom H, Anholm JM. A study of the relationship between incisor intrusion and root short-ening. Am J Orthod Dentofacial Orthop 1989;96:390–396.

58. Dermaut LR, De Munck A. Apical root resorption of upper incisors caused by intrusive tooth movement: A radiographic study. Am J Orthod Dentofacial Orthop 1986;90:321–326.

59. Linge L, Linge BO. Patient characteristics and treatment variables associated with apical root resorption during orthodon-tic treatment. Am J Orthod Dentofacial Orthop 1991;99:35–43.

Case Reports


1 Private Practice, Beirut, Lebanon.

2 Clinical Associate, Department of Orthodontics, American University of Beirut, Beirut, Lebanon; Associate Professor, Department of Orthodontics, Lebanese University, Beirut, Lebanon.

CORRESPONDENCE Dr Chadi Antoine Kassir Massoud Centre Main Road, first floor Bikfaya, El Metn Lebanon Email: [email protected]

Orthodontic management of an originally surgically planned treatment of an open bite: A case report

Chadi Kassir, DDS, DEA, DESSO1

Samar Bou Assi, DDS, MS2

The treatment of open bite malocclusion is generally considered a challenge due to its multifactorial etiology. Many treatment modalities to correct open bites, including orthognathic surgery and dental compensation, have been proposed. Dental compensation (intruding the posterior teeth and uprighting and extruding the anterior teeth with elastics) is a treatment option for borderline patients and those who are reluctant to undergo surgery. This report documents the treatment of a patient with a severe skeletal open bite malocclusion whose treatment plan originally included fixed appliance therapy as well as orthognathic surgery. He was subsequently treated with only fixed appliances. The patient, a male 17 years, 7 months of age, presented with a Class II, Division 1 malocclusion, 5 mm anterior open bite, and an increased anterior facial height. He was treated with extraction of the maxillary and mandibular premolars, full fixed appliances, and anterior vertical elastics. After 30 months of active treatment, a Class I occlusion with improved overjet and overbite was achieved. ORTHO 2011;12:60–69.

Key words: open bite, surgical treatment, hyperdivergent pattern

An anterior open bite can be defined as the presence of negative over-bite between the incisal edges of the maxillary and mandibular teeth, with the posterior teeth in occlusion.1–4 The cause of an anterior open

bite is generally multifactorial and can be due to a combination of skeletal, dental, and soft tissue effects. Many potential etiologic factors, including un-favorable growth patterns,5,6 digit-sucking habits,7–9 enlarged lymphatic tis-sue,7,10 heredity,8,11 and oral functional matrices,12 have been considered. The characteristics of individuals with anterior open bites include one or more of the following: excessive gonial, mandibular, and occlusal plane angles; short mandibular body and ramus; increased lower anterior facial height and de-creased lower posterior facial height; decreased upper anterior facial height; retrusive mandible; Class II tendency; divergent cephalometric planes; steep anterior cranial base13; and inadequate lip seal.5


Some studies have found a correlation between orofacial musculature and facial structure, suggesting a relationship between weak musculature and a long face–anterior open bite pattern.14,15

Due to the variety of causes, many treatment options have been suggested for correcting anterior open bites. Among the treatments used are habit-break-ing appliances; bite blocks; high-pull headgear therapy; and molar intrusion with temporary anchorage devices, vertical-pull chin cups, vertical elastics, multiloop edgewise archwire therapy, and surgical correction.

The following case report illustrates the treatment of a Class II malocclusion with superimposed severe crowding in both arches, an anterior open bite of 5 mm, and severe hyperdivergence.

CASE REPORT

A male, 17 years, 7 months of age, presented to the Department of Ortho-dontics Lebanese University seeking treatment. The patient’s chief complaints were the high position of his maxillary left canine and his anterior open bite.

Pretreatment facial photographs (Fig 1) show a straight profi le, an average nasolabial angle, an increased lower facial height, lip incompetency at rest, and slight chin deviation to the left. When he smiled, the full crowns of the maxillary incisors was shown as well as 4 to 6 mm of gingival display. Pretreat-ment intraoral photographs (Fig 1) reveal an anterior open bite of 5 mm with an overjet of 3 mm. In addition, two distinct occlusal planes were present in the maxillary arch. Severe crowding was present: constricted arch form and the complete blockage of the left canine in the maxillary arch and the complete lingual blockage of the mandibular right second premolar in the mandibular arch. The upper dental midline was deviated 2 mm to the left and the lower midline 1 mm to the right. Transversally, a unilateral crossbite on the left side was present, starting from the lateral incisor to the second molar. Sagittally, the maxillary right fi rst molar was in a full Class III relationship with the mandibular right fi rst molar and in a Class II relationship end on on the left side; the canines on both sides were in an end-on Class II relationship.

Radiography showed restorations at the mandibular right second molar level and that the mandibular left fi rst molar had been treated endodontically (Fig 2).

Orthodontic management of an originally surgically planned treatment of an open biteCase Reports


Initial cephalometric analysis (T1) showed a skeletal Class I relationship (ANB 0 degree) with bimaxillary retrusion (SNA\SNB 76 degrees). The mandib-ular plane angle was very steep, and the gonial angle was severely increased (MP/FH, GoA), but the mandibular body length and ramus height were with-in the normal range. The maxillary incisors were well positioned (U1\SN 103 degrees), and the mandibular incisors were severely retroclined (L1\MP 74) (Table 1).

Fig 1 Pretreatment extra- and intraoral photographs.


Kassir and Bou Assi Case Reports

63

Fig 2 Pretreatment panoramic radiograph and lateral cephalogram.

Table 1 Pre- and posttreatment cephalometric measurements

Measurement Norm Before treatment (T1) After treatment (T2)

Skeletal

SNA angle (degrees) 82 76 75

SNB angle (degrees) 80 76 75

ANB angle (degrees) 2 0 0

FH-NA (degrees) 90 86 86

FH-NP (degrees) 87 86 86

Witts (mm) 1 –10 –8

SN-MPA(degrees) 32 51 51

FMA (degrees) 25 42 41

Dental

UI-SN (degrees 103 104 95

UI-NA (degrees) 22 28 20

UI-NA (mm) 4 10 5

LI-NB (degrees) 25 21 17

LI-NB (mm) 4 5 3

LI-MP (degrees) 87 74 70

LI- APO (mm) 1 5 2.5

UI-LI (degrees) 131 131 143

Soft tissue

Holdaway line (mm)

Tip of nose (mm) 9 10 11

Subnasal (mm) 5 5 5

Upper lip (mm) 0 0 0

Lower lip (mm) 0 1 0

Supramentale (mm) 5 3 6

Pogonion (mm) 0 0 0



The patient was a mouth breather and had a tongue thrust at rest. He also lisped with the “s” sound. Temporomandibular joint (TMJ) examination re-vealed clicking on both sides with no pain.

Ideal treatment objectives were as follows. Extraorally, the objective was to decrease the lower facial height, correct the excessive gingival display upon smiling, widen the maxilla to minimize the buccal corridors, and correct the chin deviation. Intraorally, we hoped to achieve a Class I relationship with ideal overjet and overbite, relieve the crowding, correct the crossbite on the left side, and correct the midlines.

Three treatment alternatives were presented to the patient. The first option consisted of orthodontic treatment with the extraction of the four first premo-lars to correct maxillary and mandibular crowding as well as midlines deviations and to decompensate and prepare for orthognatic surgery (surgically assisted expansion if the suture did not open with rapid palatal expansion as well as maxillary impaction and mandibular autorotation or genioplasty to correct chin deviation). The second option was nonsurgical and would have entailed differ-ential extraction of the maxillary and mandibular second premolars to maintain vertical control and close the anterior openbite with vertical elastics.

The third option included the use of mini-implants to intrude the molars to rotate the mandible counterclockwise. This would be followed by extraction of the mandibular and maxillary second premolars to relieve the crowding and correct the midlines.

Clinicians recommended and the patient subsequently chose the first treat-ment plan, which consisted of extracting the first premolars to correct crowd-ing and midlines followed by orthognatic surgery to correct the gummy smile.

After caries control and oral hygiene instruction, a Hyrax appliance with bands attached to the first premolars and the first molars was used for rapid maxillary expansion. The appliance was activated twice a day for 14 days, re-sulting in approximately 7 mm of arch widening at the level of the first mo-lars and 4 mm of diastema between central incisors with suture opening. The crossbite was slightly overcorrected on the left side, and no reverse crossbite occurred on the right side. The screw was then locked with a brass wire, and the expander served as a stabilizer.

Preadjusted edgewise appliances (Roth prescription, 0.022 × 0.028-inch slot) were placed in both arches. The arches were leveled and aligned with a progression of archwires, starting with 0.014-inch nickel-titanium (Ni-Ti) wires. The four first premolars were extracted when a 0.018-inch stainless steel wire was reached. The Hyrax appliance was left in place during canine retraction after cutting the arms off the premolars. The maxillary and mandibular canines were distalized with elastic chains. (Some Class II correction was to be expect-ed after maxillary impaction and mandibular autorotation; therefore, the case was to be prepared presurgically with a Class II molar and canine relationship.) The maxillary left canine was aligned at first with an overlay and was then en-gaged into the main archwire and distalized.

While preparing for orthognatic surgery and closing extraction spaces, the pa-tient decided not to undergo surgery. An in-progress lateral cephalometric radio-graph was taken, and the revised objectives were to achieve a Class I relationship on both sides with proper overbite and overjet while maintaining vertical control.

Class II elastics to correct the Class II malocclusion, as well as anterior vertical elastics at the lateral incisors in combination with a step down on the maxillary incisors, were used to achieve a normal overbite. Once the desired overbite was attained, the patient was asked to stop the vertical elastics after 2 months of stabilization. No relapse was noticed. The fixed appliances were removed, and a maxillary Hawley retainer was delivered (some acrylic was removed anterioraly as a tongue position reminder), and a mandibular 3–3 retainer was bonded. Total

“

”

Extraorally, the objective was to decrease the lower facial height, correct the excessive gingival display upon smiling, widen the maxilla to minimize the buccal corridors, and correct the chin deviation. Intraorally, we hoped to achieve a Class I relationship with ideal overjet and overbite, relieve the crowding, correct the crossbite on the left side, and correct the midlines.



65

treatment time was 30 months. Retention was mainly directed toward preventing relapse in the transverse dimension. The patient was instructed to wear his maxil-lary Hawley retainer full-time for 6 months, then for 6 months only at night, and then 3 times a week at night. The mandibular retainer consisted of a 0.7-mm wire bonded to the lingual surfaces of the canines. The lingual retainer could be kept permanently to enhance the long-term stability of the results.

RESulTS

The treatment objectives were achieved, thanks in part to perfect patient co-operation with intraoral elastics and oral hygiene.

Extraorally, facial harmony and lip closure were achieved. When the patient smiled, no increase in the gingival display was visible, and maxillary arch ex-pansion was noted. Intraorally, bilateral Class I molars and canines relation-ships were evident. Both dental midlines were aligned with the facial midline, and optimal overjet and overbite relationships were achieved (Fig 3).

Fig 3 Posttreatment extra- and intraoral photographs.



The posttreatment cephalometric tracing and superimposition analysis re-vealed a similar ANB angle as T1 (Figs 4 and 5, Table 1). No changes in the verti-cal measurements were noted, indicating that the mechanics used controlled the vertical movement of the posterior teeth. The maxillary and mandibular incisors were extruded and retroclined. Soft tissue analysis showed slight retraction of the upper and lower lips by 1 mm, which maintained a normal relationship to the Holdaway line of the chin, lips, and nose and improved the lip closure at rest. The posttreatment panoramic radiograph showed that the roots of the teeth were fairly parallel. Supporting tissues appeared healthy and only minimal apical blunting occurred (especially at the level of the maxillary incisors).

Photographs 2 years 3 months after debonding show no relapse of the an-terior open bite or crowding but some mandibular extraction space opening (Fig 6).

Fig 4 Posttreatment panoramic radiograph and lateral cephalogram.

Fig 5 Superimpositions: ini-tial (solid line) and final (dashed line).



67

DISCuSSION

Knowing the limitations of orthodontic treatment, most orthodontists would agree that skeletal open bites are ideally treated with a combination of orthodontics and orthognathic surgery.16 The advantages of the surgical option are that the overbite can be overcorrected and the gummy smile corrected, so posttreatment stability is better than that with a nonsurgical option.17 In a nonsurgical plan, orthodontic treat-ment consists of camouflaging the skeletal discrepancies to an extent that overcor-rection, esthetics, and functional concerns can be addressed to the greatest extent the case will allow. According to Hiller,16 nonsurgical correction usually requires a longer treatment time and is more difficult, especially for stability and retention.

When orthognathic surgery is planned and orthodontic treatment is initi-ated to prepare for decompensation, it is very troublesome to revise treatment objectives and finish the case properly without surgery. This case report docu-ments the successful orthodontic treatment of an adult patient; with a severe

Fig 6 Extra- and intraoral photographs 2 years 3 months after debonding.



hyperdivergent pattern characterized by an open bite and gummy smile, it was originally intended to be treated with surgery, but the patient refused surgery while orthodontic preparation was in progress.

The premolars were extacted to relieve crowding and allow some incisor ret-roclination and step down on the maxillary incisors and step up on the mandib-ular incisors. Anterior vertical elastics were used to extrude the anterior teeth.

Anterior vertical elastics can create a vertical extruding force on the anterior teeth; as a result, the incisors tend to upright, which happened in this case.13,18

Simple extrusion of anterior teeth to correct open bite has been criticized as being unstable, and Ellis and McNamara19 even reported that the vertical height of the anterior maxilla was already increased in the open bite group. However, in the patient, no pre- or postoperative changes occurred in the amount of gingival display upon smiling.

Sarver and Weissman20 proposed some useful guidelines for the nonsurgi-cal treatment of adult patients with open bite who have no potential for growth modification. They discussed clinical results using extraction and retraction for dental open bite correction. It is emphasized that there are a limited number of open bites amenable to this type of treatment. Patients who are candidates for this type of therapy should meet the following criteria: (1) proclined or procum-bent maxillary or mandibular incisors, (2) little or no gingival display upon smil-ing, (3) normal craniofacial pattern, and (4) no more than 2 to 3 mm of maxillary incisor exposure at rest. According to those criteria, this case did not qualify for nonsurgical treatment.

Stability is a particular concern with open bite malocclusions. Studies of long-term results of open bite orthodontic treatment by Lopez-Gavito et al13 and surgically treated cases by Denison et al17 indicate that the relapse rate can range from 35% to 42.9%. The data from the Denison et al17 study suggested that relapse was caused by dentoalveolar changes, not skeletal changes. This is an indication of the importance of retainer wear. It is especially important to prevent labial flaring of the incisors. Placing retainers with occlusal coverage may be helpful in preventing further molar eruption, especially in patients with remaining growth. The first requirement to enhance stability is to eliminate the cause of the open bite. If tongue posture and aberrant function can cause an open bite, it is possible they may have a significant role in posttreatment relapse often observed in patients with open bite. Placement of a tongue crib may improve stability in patients with pretreatment open bites. In selected cases in which tongue posture or function is an apparent factor, some form of crib therapy during or after treatment may offer enhanced stability.21,22 Pro-longed retention with fixed or removable retainers is advisable and necessary in most cases of anterior open bite treatment.

The findings reported by Lopez-Gavito et al13 and Denison et al17 indicate a rather high rate of relapse in patients treated for open bite. Whereas these numbers may appear discouraging, it should be noted that the relapse rate in-cludes some patients who experienced a reduction of posttreatment overbite but did not progress to an open bite. Although correction of an open bite can-not always be perfectly maintained, there are many patients who will benefit considerably from treatment with only orthodontic appliances. Prudent selec-tion of patients and adherence to sound orthodontic principles can produce very acceptable and, at times, outstanding treatment results.

Chang et al23 reported that there is a difference in stability between open bite treatments that involve nonextraction vs extraction approaches. The ex-traction approach seems to be more stable.

Treating this case nonsurgically did not allow for the correction of the exces-sive gingival display or for optimal positioning of the incisors in the basal bone. Enhanced stability could also have been achieved with orthognathic surgery.

“

”

Although correction of an open bite cannot always be perfectly maintained, there are many patients who will benefit considerably from treatment with only orthodontic appliances.



69

CONCluSION

The treatment outcome of this severely hyperdivergent phenotype with an anterior open bite was a great improvement in both function and esthetics, although the stability of the open bite closure is questionable. The main rea-son this patient could be successfully treated nonsurgically was the posterior vertical control while the occlusal planes were anteriorly brought toward each other in addition to the patient’s excellent treatment compliance.

ACKNOwlEDgMENT

The authors would like to acknowledge Dr Maria Haydar for her contribution to the article.

REFERENCES

1. Almeida RR, Almeida-Pedrin RR, Almeida MR, Ferreira FPC, Pinzan A, Insabralde CMB. Displasias verticais: Mordida aberta anterior—Tratamento e estabilidade. Rev Dent Press Orthodon Ortop Facial 2003; 8:91–119.

2. Almeida RR, Ursi W. Anterior open-bite, etiology and treatment. Oral Health 1990; 80:27–31.

3. Pedrin F, Almeida MR, Almeida RR, Al-meida-Pedrin RR, Torres F. A prospective study of the treatment effects of a remov-able appliance with palatal crib combined with high-pull chincup therapy in anterior open-bite patients. Am J Orthod Dento-facial Orthop 2006;129:418–423.

4. Torres F, Almeida RR, de Almeida MR, Almeida-Pedrin RR, Pedrin F, Henriques JFC. Anterior open-bite treated with a palatal crib and high-pull chin cup therapy. A prospective randomized study. Eur J Orthod 2006;28:610–617.

5. Bell WH. Correction of skeletal type of ante-rior open bite. J Oral Surg 1971;29:706–714.

6. Nahoum HI. Vertical proportions: A guide for prognosis and treatment in anterior open bite. Am J Orthod 1977;72:128–146.

7. Atkinson SR. “Open-bite” malocclusion. Am J Orthod 1966;52:877–886.

8. Mizrahi E. A review of anterior open bite. Br J Orthod 1978;5:21–27.

9. Subtelny JE, Sakuda M. Open bite diag-nosis and treatment. Am J Orthod 1964; 50:337–358.

10. Linder-Aronson S. Adenoids. Their effect on mode of breathing and nasal airway and their relationship to characteristics of the facial skeleton and the dentition. Acta Otolaryngol Suppl 1970;265:1–132.

11. Sassouni V. A classification of skeletal fa-cial types. Am J Orthod 1969;55:109–123.

12. Moss ML, Salentijn L. Differences between functional matrices in anterior open-bite and deep overbite. Am J Orthod 1971; 60:264–280.

13. Lopez-Gavito G, Wallen TR, Little RM, Joondeph DR. Anterior open-bite maloc-clusion: A longitudinal 10-year postreten-tion evaluation of orthodontically treated patients. Am J Orthod 1985;87:175–186.

14. Proffit WR, Fields HW. Occlusal forces in normal- and long-face children. J Dent Res 1983;62:571–574.

15. Straub W. Malfunctions of the tongue. Am J Orthod 1960;46:404–424.

16. Hiller ME. Nonsurgical correction of Class II open bite malocclusion in an adult patient. Am J Orthod Dentofacial Orthop 2002; 122:210–216.

17. Denison TF, Kokich VG, Shapiro PA. Stability of maxillary surgery in open bite versus non-open bite malocclusions. Angle Orthod 1989;59:5–10.

18. Gehring D, Greeseman M, Frazier M, Southard K. Extraction treatment of a Class II, Division 1 malocclusion with ante-rior open bite with headgear and vertical elastics. Am J Orthod Dentofacial Orthop 1998;113:431–436.

19. Ellis E, McNamara JA. Components of adult Class III open-bite malocclusion. Am J Orthod 1984;86:277–290.

20. Sarver DM, Weissman SM. Nonsurgical treatment of open bite in nongrowing pa-tients. Am J Orthod Dentofacial Orthop 1995;108:651–659.

21. Huang GJ, Justus R, Kennedy DB, Kokich VG. Stability of anterior open bite treated with crib therapy. Angle Orthod 1990;60: 17–26.

22. De Cuebas JO. Nonsurgical treatment of a skeletal vertical discrepancy with a significant open bite. Am J Orthod Dento-facial Orthop 1997;112:124–131.

23. Chang Y, Moon SC. Cephalometric evalu-ation of the anterior open bite treatment. Am J Orthod Dentofacial Orthop 1999; 115:29–38.

Practice Pearls


1 Private Practice, Scranton, Pennsylvania, USA.

2 Clinical Professor, Department of Orthodontics, University of Pittsburgh School of Dental Medicine, Pittsburgh, Pennsylvania, USA.

CORRESPONDENCE Dr Joseph R. Karam 600 Lackawanna, Suite 200 Scranton, PA 18503 Email: [email protected]

Dental amalgam corrosion in vacuum-formed retainers

Joseph R. Karam1

Daniel J. Rinchuse2

Aim: To report and evaluate the confinement of metal ions released by dental amalgam restorations in vacuum-formed thermoplastic retainers (VFRs). Methods: VFR samples that contained corrosion tarnish corresponding with dental amalgam restorations were collected from patients, and replacement retainers were fabricated. The stained retainers were tested for trace metals utilizing inductively coupled plasma-atomic emission spectrometry (ICP-AES) and for mercury utilizing cold-vapor atomic absorption (CVAA). The results were compared to a control piece of VRF material from the manufacturer. Results: The tarnished sections of the VFRs contained mercury (61.00 ppm), calcium (205.00 ppm), and zinc (3.05 ppm). The control sample results were below qualitative limits for metal ion and mercury testing and can be considered, for our purposes, to be uncontaminated. Conclusion: VFRs that cover surfaces of teeth restored with dental amalgam become tarnished and confine amalgam corrosion products, including mercury and zinc. ORTHO 2011;12:70–74.

Key words: aligners, staining, thermoplastic

Vacuum-formed thermoplastic retainers (VFRs) are widely used in ortho-dontics in part because they are highly esthetic. VFRs are commonly composed of polyester, polypropylene, polyethylene, or copolymer

blends as well as stabilizers.1 Several patients from a private practice (D.R.) pre-sented with concerns about tarnished areas in their retainers (Fig 1). Rinchuse et al first reported VFR staining in 2007.2 Clinical examinations revealed that the tarnish marks correspond with amalgam dental restorations. Studies have evaluated the physical durability and environmental adsorption of some of these plastics when used as retainers or aligners3,4; however, no studies have evaluated the interaction between VFR and amalgam dental restorations, spe-cifically the staining of VFR associated with dental amalgam corrosion prod-ucts. The aim of this article is to discuss the potential interaction between VFR and amalgam dental restorations and to chemically identify what components of amalgam restorations stain VFRs.

Metal ions including zinc, copper, and silver are released as corrosion prod-ucts from dental amalgam. It is well documented that elemental mercury vapor is released from dental amalgam and that mercury vapor release increases upon mastication.5 Elemental mercury exists as a vapor at oral temperature and as a volatile liquid at room temperature. Elemental mercury can adsorb into and pass through many plastics.6 Mercury spills or waste from laboratory use or commercial use (ie, light bulbs or thermometers) contained in plastic bags or containers can adsorb into or permeate the plastic. Researchers at


Brown University recently developed nanomaterial sorbents in plastic packag-ing capable of capturing mercury vapor release from broken compact fl uores-cent lamps, thereby decreasing the risk of mercury vapor release.7 There have been reports of mercury-based preservatives metabolizing and escaping from plastic containers and decreasing the shelf life of some pharmaceuticals.8

From what is known about elemental mercury and its interaction with plas-tic, including polypropylene and polyethylene, it can be suggested that mer-cury released from dental amalgam restorations adsorbs into and permeates through the plastics in VFRs.

Mercury in dental amalgam is a topic of debate. Two prominent randomized controlled trials have concluded that the low level of mercury released from dental amalgams has no neurobehavioral or renal adverse effects in children, establishing justifi cation for the continued use of dental amalgam as a restor-ative material.8,9 Any further discussion of the use of mercury in dental amal-gam is beyond the scope of this paper.

METHODS

Sample collectionSeven VFR samples (Fig 1) collected from a private practice (D.R.) containing a total of 11 tarnished areas corresponding with 11 dental amalgam restorations were collected from patients; replacement retainers were fabricated. These VFRs show modest staining. The authors have observed other patients whose VFRs exhibit extreme staining as shown in Fig 2. Since the authors did not anticipate reporting these fi ndings, the samples were initially stored in plastic bags in a dark storage area for about 2 months prior to testing. However, when we decided to carry out this investigation, approximately 2 weeks before actual testing, the samples were stored in a glass jar, restricted from light, and refrig-erated at 4°C. The type of thermoplastic material used in the tested VFRs was not originally documented; possibilities are Neoform, Duraforce, and Essix C+ (all Dentsply, GAC International). Amalgam corrosion staining has been noted in VFRs made of each of these materials.

Sample analysisTarnished sections of the VFRs corresponding to amalgam dental fi llings were cut out and digested accordingly. The samples were tested for mercury utilizing cold-vapor atomic adsorption (CVAA) (EPA method 7471, Lancaster Laborato-ries), which is based on the absorption of radiation (wavelength of 253.7 nm) by mercury vapor. Mercury vapor extracted from a sample passes through a cell in the light path of an atomic absorption spectrophotometer, and peak height absorbance is measured as a function of mercury concentration. The samples were tested for trace metals utilizing inductively coupled plasma-atomic emis-sion spectrometry (ICP-AES) (EPA method 6010B, Lancaster Laboratories) in

Dental amalgam corrosion in vacuum-formed retainersPractice Pearls


which the digested samples are nebulized and the aerosol transported to a plas-ma torch. Individual element specific emission spectra are produced by radio-frequency inductively coupled plasma. Photosensitive devices monitor the intensity of the emissions, which are categorized by element. For comparison and as a control, an unstained, unused sample of Duraforce was also tested.

RESULTS

Table 1 displays results from CVAA and ICP-AES sample testing. The tarnished sec-tions of the VFR contained mercury (61.00 ppm), calcium (205.00 ppm), and zinc (3.05 ppm). The control sample results were below qualitative limits for metal ion and mercury testing; therefore, any contaminants can be considered negligible.

DISCUSSION AND CONCLUSION

The results indicate that corrosion products from dental amalgam, including mercury and zinc, are confined by VFR material. Future studies need more rigorous documentation and identification of the types of VFR materials that develop corrosion staining and in what time frame.

Fig 1 (Left) Tested VFR sam-ples containing corrosion cor-responding to dental amalgam restorations.

Fig 2 (Right) An example of extreme dental amal-gam staining on a VFR.


Karam and Rinchuse Practice Pearls

73

Inquiry about potential morbidity from mercury being retained in VFRs is understandable. It is the opinion of the authors that due to the diminutive total amount of mercury in the retainer, there should be little associated morbidity. However, the type of mercury must be considered when discussing potential morbidity. Currently, the authors have not tested for type of mercury confined in the VFR, but it is likely to be either elemental or inorganic mercury. Some data suggest that oral bacteria can metabolize elemental mercury released from dental restorations into very toxic forms of organic mercury, including methyl mercury; however, no reports of morbidity associated with this phe-nomena have been found.11

The presence of zinc in the stained VFR samples suggests that either small portions of the restoration are embedded in the retainer containing both mer-cury and zinc or that a potential inorganic mercury salt containing zinc is form-ing in the retainer. In the case that the type of mercury found in the VFRs is in the elemental form, the concentration of mercury reported in Table 1 may be undervalued. This study was conducted a priori, and as such, the samples were stored longer than ideal prior to testing. Due to the volatile nature of elemen-tal mercury, the mercury concentration found in the VFR samples at the time of testing (61 ppm) may be significantly lower than the concentration of mercury in the VFRs at the time the samples were originally collected. Also, the stained VFR samples tested in this study were modestly stained. Other cases that had

Table 1 Results of CVAA and ICP-AES sample testing

ElementControl sample

(unstained VFR; in ppm)Experimental sample (stained VFR; in ppm)

Mercury < quantitative limit (0.06) 61.00

Aluminum < quantitative limit (20.00) < quantitative limit (20.00)

Calcium < quantitative limit (20.00) 205.00

Iron < quantitative limit (20.00) < quantitative limit (20.00)

Magnesium < quantitative limit (10.00) < quantitative limit (10.00)

Potassium < quantitative limit (50.00) < quantitative limit (50.00)

Sodium < quantitative limit (100.00) < quantitative limit (100.00)

Thallium < quantitative limit (3.00) < quantitative limit (3.00)

Arsenic < quantitative limit (2.00) < quantitative limit (2.00)

Selenium < quantitative limit (2.00) < quantitative limit (2.00)

Antimony < quantitative limit (2.00) < quantitative limit (2.00)

Barium < quantitative limit (0.50) < quantitative limit (0.50)

Beryllium < quantitative limit (0.50) < quantitative limit (0.50)

Cadmium < quantitative limit (0.50) < quantitative limit (0.50)

Chromium < quantitative limit (1.50) < quantitative limit (1.50)

Cobalt < quantitative limit (0.50) < quantitative limit (0.50)

Copper < quantitative limit (1.00) < quantitative limit (1.00)

Lead < quantitative limit (1.50) < quantitative limit (1.50)

Manganese < quantitative limit (0.50) < quantitative limit (0.50)

Nickel < quantitative limit (1.00) < quantitative limit (1.00)

Silver < quantitative limit (0.50) < quantitative limit (0.50)

Vanadium < quantitative limit (0.50) < quantitative limit (0.50)

Zinc < quantitative limit (2.00) 3.05

Bolded items were greater than the quantitative limit.

“”

Mercury released from dental amalgam restorations adsorbs into and permeates through the plastics in VFRs.

Dental amalgam corrosion in vacuum-formed retainersPractice Pearls


more extreme staining would have obviously shown more mercury adsorption. Further studies focusing on the type of mercury in VFRs, total mercury volume contained in VFRs in vivo, and potential metabolism or chemical conversion of mercury adsorbed into the VFR need to be conducted.

Although corrosion materials from dental amalgam end up confined in VFRs, variables that increase or decrease the concentration of these materials need to be evaluated, including VFR prescription (full-time wear vs part-time wear), VFR age, mechanical interaction between the VFR plastic and amalgam resto-ration, chemical or electrochemical interaction between the VFR plastic (and its stabilizing agents) and the amalgam restoration, eating or drinking habits (eg, drinking hot beverages or eating with the retainers seated), and oral hygiene habits (eg, hydrogen peroxide usage). Amalgam corrosion staining may be less of an esthetic issue for patients utilizing thermoplastic materials as align-ers, such as Invisalign (Align Technology), since patients often switch to the next aligner in a series prior to staining.

Some immediate remedies for amalgam corrosion in VFRs are as follows. Rinchuse et al advocated in a recent publication2 wearing VFRs canine-to-canine only at night, except in open-bite or extraction cases, because this would allow the posterior and buccal segments to settle after orthodontic treatment. Also, canine-to-canine VFRs offer greater flexibility than full-coverage VFRs, so mov-ing teeth is easier. Another obvious solution is to use Hawley or fixed retainers in place of VFRs.

Corrosion products from dental amalgam including mercury and zinc can be confined by VFR material. Further studies are needed to evaluate the amalgam staining characteristics of different VFR plastics; the type and concentration of mercury in VFRs; and the possible mechanical, chemical, and electrochemical interactions between VFRs and amalgam restorations.

REFERENCES

1. Sheridan JJ, Hilliard K, Armbruster P. Es-six Appliance Technology: Applications, Fabrication and Rationale. Bohemia, NY: GAC International, 2003.

2. Rinchuse DJ, Miles P, Sheridan JJ. Orth-odontic retention and stability: A clinical perspective. J Clin Orthod 2007;41: 125–132.

3. Lindauer SJ, Shoff RC. Comparison of Essix and Hawley retainers. J Clin Orthod 1998;32:95–97.

4. Schuster S, Eliades G, Zinelis S, Eliades T, Bradley TG. Structural conformation and leaching from in vitro aged and retrieved Invisalign appliances. Am J Orthod Den-tofacial Orthop 2004;126:725–728.

5. Mackert JR Jr, Berglund A. Mercury exposure from dental amalgam fillings: Absorbed dose and the potential for adverse health effects. Crit Rev Oral Biol Med 1997;8:410–436.

6. Parker JL, Bloom NS. Preservation and storage techniques for low-level aque-ous mercury speciation. Sci Total Environ 2005;337:253–263.

7. Johnson N, Manchester S, Sarin L, Gao Y, Kulaots I, Hurt R. Mercury vapor release from broken compact fluorescent lamps and in situ capture by new nanomaterial sorbents. Environ Sci Technol 2008;42: 5772–5778.

8. Reader M, Lines CB. Decomposition of thimerosal in aqueous solution and its determination by high-performance liquid chromatography. J Pharm Sci 1983;72: 1406–1409.

9. Bellinger DC, Trachtenberg F, Barregard L, et al. Neuropsychological and renal effects of dental amalgam in children: A randomized clinical trial. JAMA 2006; 295:1775–1783.

10. DeRouen TA, Martin MD, Leroux BG, et al. Neurobehavioral effects of dental amal-gam in children: A randomized clinical trial. JAMA 2006;295:1784–1792.

11. Heintze U, Edwardsson S, Derand T, Birkhed D. Methylation of mercury from dental amalgam and mercuric chloride by oral streptococci in vitro. Scand J Dent Res 1983;91:150–152.

“

”

Amalgam corrosion staining may be less of an esthetic issue for patients utilizing thermoplastic materials as aligners . . . since patients often switch to the next aligner in a series prior to staining.

757575

Treatment PlanningCHALLENGE 1

S o often, our peers can teach us far more than any book: The Treatment Planning Challenge is designed to be a forum for readers to learn from one another. In each issue, we will present a complex

case, complete with intra- and extraoral photographs, panoramic and cephalometric radiographs, and cephalometric data as well as any essential anamnestic details.

After reviewing the case, readers are encouraged to detail their own treat-ment plan (in no more than 250 words) and provide answers to the accom-panying questionaire. In the next issue, we will outline with photographs, radiographs, and data how the clinician actually treated this case and its out-come, as well as some of the most interesting reader responses and the statisti-cal distribution of the questionaire answers.

Tell us your treatment plan for this case (answers will edited for clarity, lan-guage, and length) at http://www.quintpub.com. Click the Journals link at the top of the page and then the Orthodontics cover. Please submit your plan for this case by June 1, 2011, and note that it is for Treatment Planning Challenge no. 1.

Send us your completed challenging case for a future issue: Provide all pre- and posttreatment records as well as a short of explanation of why you chose the treatment plan you did at http://www.manuscriptmanager.com/ortho. Select TPC (new case) from the Manuscript Type drop-down menu. Low-resolution images are acceptable for the review process; however, if your case is chosen for publication, keep in mind that you will need to provide images that are at least 300 dpi at 3.5 inches wide. You must also have signed patient consent for publication of the photographs.

Missing maxillary lateral incisors: To close or to open?

In the case of an 11-year-old girl with missing maxillary lateral incisors:

• Would you close or open the space of the missing maxillary lateral incisors?

• If you chose to close the space, would you reshape the canines upon completion of treatment?

• Would you start treatment immediately or wait ____ years?


Missing maxillary lateral incisors: To close or to open? Treatment PlanningCHALLENGE 1



Treatment PlanningCHALLENGE 1

77

Cephalometric dataNorms Patient

Maxillary skeletal

SNA (degrees) 80 < 82 < 84 78

NVertA (mm) –2 < 0 < 2 –3

Nasiolabial angle (degrees) 113 > 105 > 97 108

Upper lip–subnasale (mm) 1 > 2 > 3 0

Maxillary dental

U1 to SN (degrees) 100 < 104 < 108 93

U1 to PAL/PL (degrees) 105 < 110 < 115 108

U1 to NA (degrees) 18 < 22 < 26 15

U1 to NA (mm) 2 < 4 < 6 0

Upper lip drape (degrees) 92 < 97 < 102 91

Mandibular dental

IMPA 90 < 95 < 100 88

Incisor to NB (degrees) 21 < 25 < 29 19

Incisor to NB (mm) 2 < 4 < 6 3

Incisor to AP (mm) 0 < 2 < 4 –2

Half Steiner (mm) –5 < 0 < 5 –1

Mandibular skeletal

SNB (degrees) 78 < 80 < 82 73

Facial angle (Downs) (degrees)

86 < 89 < 92 85

NaVertPo (mm) –9 < –6 < –3 –10

E angle (degrees) 68 < 72 < 76 64

Vertical

GoGn–SN (degrees) 28 < 32 < 36 37

OM angle (degrees) 15 < 20 < 25 17

Y-axis 64 < 67 < 70 68

Jarabak SGo:NMe (%) 62 < 64 < 66 60

Anterior facial height (%) 55 ± 2 51

Tell us your treatment plan for this case at http://www.quintpub.com.

Management


1 Department of Organizational Behavior, Faculty of Management, Recanati Graduate School of Management, Tel Aviv University, Tel Aviv, Isreal.

CORRESPONDENCE Dr Hilla Dotan Faculty of Management Tel Aviv University Tel Aviv 69978 Israel Email: hdotan@ post.tau.ac.il

The dentist as a manager: Building effective relationships and networks for personal and professional advancement

Hilla Dotan, PhD1

ORTHO 2011;12:78–81.

Many skilled and highly specialized professionals such as dentists, surgeons, scientists, and musicians invest a great deal of time and resources obtaining the required technical skills and certification, as-

suming that these will help them reach their professional goals. Unfortunately, only a limited amount of top talent also invests in gaining practical, manage-rial, and relational skills to accompany their technical expertise. Consequently, many accomplished professionals do not attain their full career potential. Many struggle to build their own businesses and lack basic knowledge with regard to hiring and product pricing. They also have difficulty determining where and if to open a private clinic; how to gain market share; how to reach a patient; and how to build long-term, effective relationships with clients, distributers, and dental staff.

One of the main reasons for this lack of critical knowledge is that many professional schools do not offer basic business courses as part of their curricu-lum. Is it because they assume their graduates will succeed regardless of such schooling? Is there no need? What percentage of professional school gradu-ates succeed in building their own practices? Who are the most successful den-tists? Are they the ones who are the top experts in their field? We often find that it is not always the most capable and skilled professionals who build the most successful practices. What is unique about those who do? What does it take to become a leader in a specialized profession?

Findings from interviews with executives and research conducted in the United States over the last decade1 suggest that the most successful leaders and professionals are those who know how to build the right relationships and manage and maintain their social networks.

In today’s business world, relationships are the new bottom line. The qual-ity and impact of one’s work and the profitability of a business depend on relationships: relationships with coworkers, patients, competitors, distributors, investors, and others. Relationships offer opportunities for mutual growth, col-laboration, innovation, information sharing, and new business development, but they also pose challenges in these respects. The distinguishing factor be-tween a successful manager and an ineffective leader is the ability to effec-tively manage relationships.

Nonetheless, most of us do not receive formal training on relational man-agement. When we enter a new organization, no one tells us with whom we should connect and whom to avoid. An organizational chart does not tell us anything about the informal side of the organization, for example, its cliques or internal politics. No one provides a manual that shows whom it is good to befriend, how to build a good relationship with a patient, or how to manage relationships with our colleagues and competitors.


Many of us spend years attempting to obtain our degrees and certifi cation and progress through our careers without much thought about our professional relationships and networks. Those of us who do pay attention to our relation-ships and build valuable connections do so intuitively and go with what feels right. Most of us do not look at someone in the organization and conduct a cost-benefi t analysis with regard to a potential friendship with this person. Why are relationships not approached strategically? We are very strategic about the type of training we get, the professional school we attend, and the location of practice, but why are we not strategic about what helps us achieve all the above? Would we not be more successful if we actually evaluated a potential relationship with someone, thought about the type of relationship we want to build with the specifi c person, and for how long we want to maintain that re-lationship? For example, wouldn’t we be better off if we thought about whom would be the best person to study with for exams at school? Who are the best individuals to work with during specialization? Whom not to befriend? These relationships are likely to infl uence and guide us throughout our careers, and it ought to be important to choose them carefully.

Since most of us deal with relationships every day and are judged by the quality of the ties that we build and maintain, and since our reputation is in the hands of these individuals, why is a course on relationship building not a re-quired course in all professional schools and disciplines? Why is it rarely offered in psychology departments and business schools around the world?

In this short commentary, I argue for the importance of not only provid-ing skilled professionals their specialized training but also preparing such top talent for the challenges they are likely to face as they enter existing work-places or as they attempt to build their own practices and clinics. I encourage professional schools to incorporate basic practical and managerial skills into their curriculum in areas such as strategy, marketing, leadership, and effec-tive relationships and social networks. Since training or courses on the latter are not readily available, I would hereby like to suggest types of analyses that professionals can conduct to refl ect on their relational skills and think of ways to improve them. In the following section, I raise a number of questions with the hope that these will guide readers as they begin to think about building ef-fective relationships and networks for personal and professional advancement.

• What does my current professional network look like?

Before thinking about improving one’s existing relationships and network, one should fi rst become aware of the status quo. Therefore, the fi rst stage is to evaluate one’s current network. As one conducts such analysis, thought should

79

Management

80

The dentist as a manager: Building effective relationships and networks

ORTHODONTICS Th e Art and Pract ice of Dentofacial Enhancement

be made with regard to direct ties as well as indirect ties—those to whom we are connected to via another person. One could make a list of all the direct and indirect ties and map all the connections in the form of a sociogram2 or a network map (Fig 1).

• What should my ideal network look like?

Once we become aware of our current network, the next step is to think about how an ideal network should look. The answer to this question is quite complex and will vary greatly from one individual to the next. A help-ful guiding question is to think about what one’s professional goals are and map the network that will help achieve those goals. For example, if my aim is to open my own clinic, the ideal network should include all the individuals I know who can help me build and maintain an effective and effi cient prac-tice. These should include colleagues who have their own practices and can provide advice and refer me to relevant sources as well as individuals who can help market my new business, friends who can help spread the word, individuals who can help me reach patients, suppliers, professional clubs, and relevant academic institutions and academies.

• What type of a relationship should I have with each person in my ideal network?

Once all the relevant individuals and constituencies are on the map, it is important to think of the type of relationship currently in place with each

fig 1 Example of a sociogram of a clinician’s ideal network. Original diagram created with Node XL.

Medschool

Colleagues

Online

Media

Josh

Admin

ProfessorsOrthodontists

Peers 2010

UnitedStates

China

Finland The Netherlands

BelgiumUnited Kingdom

DenmarkSpain

European Union

Academics

Specialists

Practitioners

David

Steven

John

Sister

Cousin

MomDad

Jessica

Stacy

Annualconference

Familynetwork

Marketingavenues

Friendswith clinics

Keycompetitors

JoshJosh

JohnJohn

Dentist

Management


Dotan

individual and the type or relationship one should have with him or her. One way to decide on the type of relationship is to conduct a needs analysis, which is divided into three stages: (1) an analysis of needs to help achieve professional goals, (2) a determination of who in my professional network can satisfy these needs, and (3) an analysis of what I can provide/offer the other to motivate him or her to build the relevant relationship with me.

To succeed professionally and achieve professional goals, we have career/professional needs and psychosocial needs.3 By conducting an analysis of these needs and then thinking who can help satisfy these needs, I can begin to think of the type of relationship I should have with each person. For example, an ex-perienced orthodontist who has a very busy schedule and cannot answer all pa-tients’ requests may decide to bring in a young orthodontist to the practice to help take some of the load. A relationship with the young colleague will require the older specialist to provide guidance and teach the younger orthodontist various procedures and best practices—a typical mentor-protégé relationship. Thus, by first identifying the need for assistance and a protégé (stage 1), the

experienced orthodontist can review all the individuals in a network and de-termine who can fulfill the protégé position (stage 2). Nevertheless, although she may want to have a mentor-protégé relationship with a specific person in her network, the other person may not be available or interested in such a relationship. Therefore, an additional analysis should be conducted to try to persuade the other person to develop the required relationship. The experi-enced orthodontist will need to demonstrate to the potential protégé the pos-sible advantages that she, as a mentor, can offer the protégé and the value of entering into such a relationship (stage 3).

Thus, an analysis of who can satisfy my various needs and what I can provide the other should be conducted to help determine with whom to connect, what type of a relationship to build with him or her, and what professional needs this relationship will satisfy. Once all the needs are satisfied using various relationships with diverse individuals, a chart of the ideal network can be derived and mapped.

The above framework is a useful guide to help map one’s ideal network for achieving personal and career goals. However, mapping the network is only the starting point. The next critical step is to think about how to actually build such relationships and maintain them—for example, how to build trust with a new patient, manage conflicts with individuals in my network, and leverage my network to enhance my reputation in my industry?

Many of us should be thinking about the above questions as we reflect on our professional relationships and networks and as we attempt to reach our business objectives. The ability to manage these effectively will determine whether we will succeed and whether we will be able to maintain that success over time.

Professional schools provide the basic knowledge and certification to prac-tice our professions. Managerial and relational skills provide us the tools to take charge of our profession and bring it to where we want it to be.

REfERENCES

1. Dotan H. Workplace friendships: Origins and consequences for managerial effec-tiveness. Academy of Management Best Paper Proceedings, 2009.

2. Wasserman S, Faust K. Social Network Analysis. Cambridge: Cambridge Univer-sity Press, 1994.

3. Hill L. Beyond the myth of the perfect mentor: Building a network of develop-mental relationships (case no. 9-491-096). Boston: Harvard Business School Case Services, 1991.

I t has been said that orthodontic practice is more of an art form than a scienti� c discipline. For the sake of argument, most clinicians would agree that in any given

day of practice, it probably is a little bit of both. However, orthodontists like to think in absolutes and would prefer to see the orthodontic

microcosm as black or white rather than shades of subtle gray. This desire to separate art from science has inadvertently created a paradigm shift in

contemporary orthodontic literature. Pick up just about any orthodontic journal, and you will � nd that the evidence-based systematic review has

supplanted the clinical narrative review of yesteryear. Orthodontics is no longer a cultural mosaic replete with a vibrant dramatis personae but a drab

melting pot of homogeneity. For those who see orthodontics as a science, this is a welcome change. For those who view it as an art, it is not.

As I re� ect on this shift, I am reminded of a wonderful vignette told to me by my father, Jim Ackerman, the second of three orthodontic generations. At a conference of German anatomists nearly a half-century ago, he and the late Melvyn Baer were presenting a case report about cebocephalia.1 When they � nished presenting the paper, the moderator opened the discussion with ques-tions from the audience. A very senior German anatomist stood up and stat-ed, “Anyone familiar with the literature knows that patients with cebocephalia do not live to the age of your patient.” My father was at a complete loss for words, facing the prospect that he had misdiagnosed the patient in the case report. Without missing a beat, Mel Baer grabbed the microphone and retorted, “Our patient has obviously not read the literature!”

Orthodontics: The Art and Practice of Dentofacial Enhancement is designed to give the reader a glimpse of both the art and science sides of the orthodontic coin. In this section, Vignettes, we have reserved a place for authors to recount (in fewer than 500 words) their unique experiences in practice and to pay hom-age to those individuals who have shaped the course of our specialty.

Marc Bernard Ackerman, DMD, MBADirector, Department of Orthodontics

Children’s Hospital Boston Boston, Massachusetts, USA

Vigne� es

CORRESPONDENCEDr Marc Bernard AckermanChildren’s Hospital Boston300 Longwood AveBoston, MA 02115Email: [email protected]

“ ”Vignette: a brief evocative description, account, or episode.

—World Dictionary

ORTHODONTICS � e Art and Pra� ice of Dentofacial Enhancement82

REFERENCE

1. Ackerman JL, Takagi Y, Prof� t WR, Baer MJ. Craniofacial growth and development in cebocephalia. Oral Surg Oral Med Oral Pathol 1965;19:543–554.

To submit an interesting Vignette, please go to http://www.manuscriptmanager.com/ortho.

• Gerard J. Chiche • Vincent G. Kokich • Sonia S. Leziy/Brahm A. Miller • John D. West • Lloyd M. Tucker • John C. Kois • Andrew M. Alpert • Frank Spear/Greggory Kinzer

• Henry I. Nichols• Neil L. Starr • Ward M. Smalley • Ariel J. Raigrodski • Stephen Rimer • Ricardo Mitrani • Galip Gürel • Michael Cohen

Contributors

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