author manuscript nih public access a, b, catherine nyssen

Patients’ and orthodontists’ perceptions of miniplates used fortemporary skeletal anchorage: A prospective study

Marie A. Cornelisa, Nicole R. Schefflerb, Catherine Nyssen-Behetsc, Hugo J. De Clerckd, andJ. F. Camilla TullocheaPhD student, Experimental Morphology Unit and Department of Orthodontics, Université Catholique deLouvain, Brussels, Belgium.

bPrivate practice, Boone, NC; adjunct assistant professor, Department of Orthodontics, University of NorthCarolina, Chapel Hill.

cProfessor, Experimental Morphology Unit, Université Catholique de Louvain, Brussels, Belgium.

dPrivate practice, Brussels, Belgium.

eProfessor, Department of Orthodontics, University of North Carolina, Chapel Hill.

AbstractIntroduction—Temporary skeletal anchorage is a relatively recent addition to orthodontictreatment. Surgical miniplates, modified with intraoral attachments, provide an alternative tominiscrews for skeletal anchorage. In this study, we wanted to determine patients’ and providers’perceptions of miniplate use during orthodontic treatment.

Methods—Consecutive patients having miniplates placed as part of their treatment completedquestionnaires about their experiences during surgery and orthodontic treatment. A total of 200miniplates were placed for 97 patients. The 30 orthodontists treating these patients also completedquestionnaires concerning miniplate success, handling complexity, and whether these devicessimplified treatment.

Results—The success rate was 92.5%. The devices were well tolerated by the patients. After a year,72% of the patients reported that they did not mind having the implant, and 82% said that the surgicalexperience was better than expected, with little or no pain. The most frequent problems werepostsurgical swelling, lasting 5 days on average, and cheek irritation experienced initially by morethan a third of the patients, but it lessened over time. The clinicians reported that these devices wereeasy to use and greatly simplified orthodontic treatment.

Conclusions—Miniplates are well accepted by patients and providers and are a safe and effectiveadjunct for complex orthodontic treatments.

Anchorage is a challenging aspect of orthodontic treatment. Conventional anchorage methodsgenerally rely on patient compliance, result in unwanted reciprocal tooth movements, and canbe limited in patients with compromised dentitions. In an effort to overcome some of theseproblems, skeletal anchorage has been increasingly incorporated into orthodontic treatment forover 25 years.1 The quest for absolute anchorage began with conventional dental implants,2retromolar implants,3 and palatal implants.4 However, space limitations, cost of the implants,and difficulties with connecting to the orthodontic appliances encouraged the rapid

Copyright © 2008 by the American Association of Orthodontists.Reprint requests to: Marie Cornelis, Experimental Morphology Unit, Universté catholique de Louvain, Av Mounier, 52/5251, 1200Brussels, Belgium; e-mail, E-mail: [email protected].

NIH Public AccessAuthor ManuscriptAm J Orthod Dentofacial Orthop. Author manuscript; available in PMC 2009 July 3.

Published in final edited form as:Am J Orthod Dentofacial Orthop. 2008 January ; 133(1): 18–24. doi:10.1016/j.ajodo.2006.09.049.

NIH

-PA Author Manuscript

NIH


NIH


development of smaller devices that could be placed in various locations in the dental arch.Miniscrews5 and miniplates,6 specifically designed for orthodontic anchorage, satisfy someof those requirements and are being progressively adopted into clinical practice.

Recently, the literature has tended to focus on miniscrews, perhaps because of their small sizeand apparent ease of placement.7–15 However, miniscrews have been associated with a fairlyhigh failure rate,16 including fracture during placement,17 loosening under loading,18 andimpingement on roots either during placement or tooth movement.13 Miniscrews might alsoneed to be repositioned during treatment to allow all intended tooth movements to beaccomplished. To address some of these issues, surgical miniplates with intraoral attachmentshave been modified to serve as temporary skeletal anchorage devices (TSAD). Miniplates,which are placed at a safe distance from the roots, offer the advantages of reduced risk of rootimpingement, allow the free movement of roots past the TSAD, and are associated with a lowerfailure rate than miniscrews.16 Claims have been made that miniplate anchorage simplifiespreviously complex treatments19 and permits correction of malocclusions previously thoughtbeyond the scope of orthodontic therapy alone.20–23 Although appearing to be safer and morestable, and extending treatment possibilities, there are few reports about this type of TSAD,and fewer still of clinician and patient perceptions of their use. Most available articles onminiplates are case reports6,24–32 or retrospectively assessed case series,16,19,22,33 withonly 1 prospective clinical trial34 reporting adverse events and outcomes during treatment,and only 1 report of patients’ opinions and experiences.16 Also, there is only 1 other studyreporting patient perceptions of TSAD use; it addresses palatal implants.35 Perhaps miniplateuse has been limited because of the perception that they are difficult to place, unpleasant anddifficult for the patient to tolerate, and cumbersome for the orthodontist to use, and might notprovide significant advantages for treatment.

This survey was undertaken to obtain information on both patient and provider experienceswith miniplates for temporary skeletal anchorage when used for various clinical conditions.We documented both patients’ and orthodontists’ perceptions of the use of miniplates andevaluated the success of the system, identifying adverse events and outcomes associated withthis adjunct to orthodontic practice.

MATERIAL AND METHODSQuestionnaires were presented to consecutive patients having miniplates placed as part of theirorthodontic treatment and to the clinicians providing their treatment at 2 university-basedorthodontic centers: University of North Carolina (UNC), Chapel Hill, and Universtécatholique de Louvain (UCL), Brussels, Belgium. Patients were enrolled between August 2003and April 2005 and completed the questionnaires in their preferred language (English orFrench). Additional parental comments were solicited for children under the age of 16. Thestudy was approved by the Institutional Review Board at UNC and the Biomedical EthicsCommission at UCL.

The questionnaires were completed at approximately 1 month, 6 months, and 1 year after TSADplacement (or on removal of the anchor, if this occurred sooner). The questions related to thepatient’s discomfort and general experiences during surgery and orthodontic treatment. Inaddition, the orthodontists were asked to assess handling complexity, the purpose for whichthe anchor was used, the success rate, their overall TSAD experience, and whether they thoughtthat these devices simplified or complicated their patient’s treatment.

All subjects at UNC and all but 3 at UCL agreed to participate in the study. One patient at UCLwas later excluded because of inability to understand the questionnaires. A total of 98.6% ofquestionnaires were completed by the patients and the orthodontists at both centers. The

Cornelis et al.

Am J Orthod Dentofacial Orthop. Author manuscript; available in PMC 2009 July 3.

NIH


NIH


NIH


patients’ and providers’ perceptions were obtained with 4-point categorical scales. Medians,means, and standard deviations were calculated for perception data, and frequencies werereported for categorical data.

The patients at UNC were paid $20 on completion of the third questionnaire.

RESULTSA total of 97 patients were enrolled (30 at UNC, 67 at UCL [Table I]). The mean age of thepatients was 23.7 years (range, 9.8–48.1 years). One third of the sample were growing patients(≤15 years of age for females; ≤19 years of age for males), and almost 75% were female. Thenumber, type, location, and success of the miniplates are given in Table II. A total of 200TSADs were placed by 9 surgeons (4 at UNC, 5 at UCL). Two types of TSADs were used (Fig1): 180 Bollards (Surgitec, Bruges, Belgium; 39 at UNC, 141 at UCL) and an additional 20 C-tubes (KLS Martin, Umkirch, Germany) were used for 10 patients at UNC. Most (76.5%) ofthe TSADs were placed in the maxilla. Implants were loaded approximately one month aftersurgery; no plates were loaded immediately. Most miniplates were in place for more than the1-year study period. Fifteen bone plates were removed prematurely, and only 6 of these werereplaced. The success rate from August 2003 to September 2006 was 92.5%. Most (73.3%)failures occurred in growing patients. The percentages and locations of failures were differentat the 2 centers. Thirty orthodontists completed questionnaires (19 at UNC, 11 at UCL). Thetypes of movement (Fig 2) for which TSADs were placed included orthodontic (Fig 3, A) andorthopedic corrections (Fig 3, B). The Bollards were loaded with elastics, coil springs, elasticchains, ligature wires, or directly with an arch-wire. The C-tubes were loaded only with coilsprings or ligature wires.

Patients’ perceptionsThe patients’ perceptions of their surgical experiences are given in Figure 4. Pain duringsurgery and orthodontic treatment was reported on a 4-point scale from no pain to severelypainful. The patients estimated their swelling after surgery as 1.8 on a scale (0, no swelling, to3, lots of swelling), lasting for 5 days on average (4.8 ± 2.3 at UNC; 5.5 ± 3.0 at UCL). Aftersurgery, either anti-inflammatory agents or painkillers (or both) were recommended but takenby only 77.1% of the patients.

In general, the TSADs were well tolerated by the patients. No patient requested to have animplant removed. After 1 year, 72% of the sample (83.3% at UNC, 66.7% at UCL) reportedthat they did not mind having the implant in place, but some expressed mildly negativecomments that included “having a foreign body in the mouth,” irritation of cheek or lip, andfood trapping around the device. Implant placement was reported to be better than expectedby 82% of the patients (93.1% at UNC; 76.4% at UCL), most frequently because they hadexpected more pain. Of the patients who reported that the implants were worse than expected,postsurgical swelling and cheek irritation were the principal reasons.

Some patients had previously had other dental procedures, including extractions, headgear,braces, and cavity restorations. They were asked to make comparisons with procedures withwhich they were familiar. The results are given in Figure 5 as the percentages of patients ateach center rating TSADs better than other dental procedures.

The patients were asked about their side effects at each time (Fig 6). The principal problemwas cheek irritation, which was most frequent soon after surgery, but decreased over time.Restricted mouth opening concerned 17% of the patients initially, but became and remainedminimal after 6 months and 1 year. Cleaning the anchors was a problem for 15% of the patients,and this continued over time. Patients were specifically instructed not to touch the TSAD with

Cornelis et al.


NIH


NIH


NIH


their tongue to prevent loosening the miniplate. However, one-third of the patients admitteddoing this, and this habit frequently persisted throughout the year that they were followed.

Orthodontists’ perceptionsThe orthodontists’ perceptions of TSAD experience is illustrated in Figure 7, A. In their firstquestionnaire, the orthodontists were asked how difficult they expected the treatment of eachpatient to be without TSADs. In general, the cases were initially expected to be somewhat tovery difficult. However, after 1 year of using the miniplates, the same patients were thenconsidered by their orthodontist to be very to moderately easy. The orthodontists judged theoverall handling complexity of the miniplates and their attachments on a 4-point scale andreported them to be very to moderately easy over the different time points. The mobility ofTSADs and soft-tissue irritation evaluated by the orthodontists at several times over a yearstayed under the level of “mild” (Fig 7, B). All orthodontists said they would use miniplatesagain and evaluated their average satisfaction at 3.8 (3.6 at UNC; 3.9 at UCL) on the scale (3,moderately satisfied, to 4, very satisfied) (Fig 7, B). If the orthodontists reported that an initialorthodontic objective could not be obtained, the reasons given were implant failure or lack ofpatient compliance.

DISCUSSIONIn general, patients, parents, and providers were enthusiastic about their experiences withminiplates as a simplifying adjunct to orthodontic treatment. Miniplates were well toleratedby the patients and were associated with few adverse events. To place miniplates in the contextof other dental procedures, it would seem that they are always perceived as better than headgear,nearly always better than braces, better (UNC) or equivalent (UCL) to extractions, and aboutequal to or worse than cavity restorations. Although the placement of miniplates requiressurgery to raise a mucoperiosteal flap and retract the tissues, these procedures appeared to beassociated with minimal perioperative pain and inconvenience, and no major recurringproblems during treatment.

This study was carried out at 2 university centers with both experienced and inexperiencedorthodontists and surgeons, and few problems occurred. The side effects reported were quitedifferent from those reported by Gunduz et al35 (difficulty in speaking, difficulty in eating,and injury to tongue) for palatal implants. Although some negative comments were recordedfrom some patients, it was not possible from this sample to determine whether there was aconsistent pattern suggesting an association between negative comments and age, placementsite, or type of treatment. The principal adverse outcome was swelling, which persisted onaverage for 5 days after surgery. Even though anti-inflammatory agents were prescribedpostoperatively, not all patients complied with this recommendation. It is probable that moreaggressive management of postoperative edema, including the use of ice packs 1 to 2 hourspostoperatively, and the addition of preoperative anti-inflammatory agents or corticosteroidsdelivered intravenously, could have prevented or at least reduced this postoperativecomplication.

Cheek irritation was another frequently reported problem, but for only 1 patient was thisconsidered severe enough to require removal of the TSADs. The initial location of theminiplates in the mandibular arch was between the canine and the first premolar; this was latermodified to between the lateral incisor and the canine. This new position decreased cheekirritation, probably because the miniplate head was less prominent. When placed at the canineeminence, lip and cheek movement, and pressure against the miniplate head, could cause soft-tissue irritation or ulceration. Moving the miniplates forward in the mandibular arch reducedthis.

Cornelis et al.


NIH


NIH


NIH


Our definition of failure was any patient whose objectives could not be achieved with the initialimplants. This included excess TSAD mobility (7), cheek ulceration (4), fractures (3), andundesirable position of the miniplate (1). Increased mobility was proportionally morefrequently reported in the mandible than the maxilla, possibly related to the flap design. Theinitial mandibular surgical protocol at UCL was modified during the study to place the releasingincision in the attached gingiva and not in the sulcus. Three failures due to mobility werereported before this change, but no further failures were observed after this change. Four mobilemaxillary miniplates, in an adult and 3 growing patients, were removed and subsequentlyreplaced: 1 because of poor plate adaptation to the bone, leaving an open pathway for infection,and the other 3 because of infection around a screw. The failure rate due to mobility in growingpatients was higher than in adults. Although the surgeons were always instructed to place theattachment arm penetrating the tissue at the mucogingival junction, this might be more difficultin younger patients, when alveolar height tends to be shallow, width of attached gingiva is less,and access is restricted. Moreover, most miniplates in growing patients were in place for longerthan 18 months. During this time, a significant amount of bone remodeling could occur; thismight also explain the higher failure rate.

In several patients, although the TSADs were described as mobile throughout treatment, theywere still sufficiently firm to provide the anchorage necessary to achieve the treatmentobjectives.

It is apparent that soft tissues play an important role in implant stability. Mucosal transfixionof the miniplate arm at the mucogingival junction or 1 mm within the attached gingiva enablestight closure of the tissues; this appears to be necessary for good soft-tissue healing.

Oral hygiene is another important factor for success. According to Miyawaki et al,16prevention of inflammation of the peri-implant tissue is a critical factor for TSAD successrates. Many patients experienced persistent difficulties in cleaning their miniplate anchors.Precise recommendations for careful brushing of the miniplate and surrounding mucosa witha soft toothbrush are important in preventing infection, which can lead to miniplate failure.

Of the 180 Bollards placed, 3 fractured, all in the intraoral connector. One fracture occurredafter the device had been subjected to repeated bending to change the force vector.

A patient with an open bite needed to have a C-tube repositioned to allow the completion ofthe intrusion of the posterior teeth. Unlike the C-tube, the Bollard anchor is designed to acceptauxiliary attachments and so provides greater flexibility in the point and direction of forceapplication.

The overall success rate of 92.5% in this study of 97 consecutive patients (with 200 TSADs)who were followed prospectively confirms the previous findings of Miyawaki et al,16 whoreported a 96.4% miniplate success rate in a retrospective study of only 17 miniplates. Aprospective study by Cheng et al,34 following 44 patients (48 miniplates, 92 miniscrews),reported an 89% success rate for both types of TSADs, but the miniplates were used in themore difficult situations.

It seems clear that both miniplates and miniscrews have the potential to augment or provideabsolute anchorage and allow orthopedic correction or orthodontic tooth movements nottraditionally thought possible with conventional anchorage methods. In addition, the unwantedreciprocal forces that almost always occur with more traditional anchorage devices were notobserved. The problem of patient compliance is simplified to the ever-present one of oralhygiene. For most clinicians participating in this study, these patients were their firstexperiences with skeletal anchorage. Yet, there was a near-unanimous report that the devicessimplified all treatments, sometimes to a remarkable extent. It may be that the use of TSADs

Cornelis et al.


NIH


NIH


NIH


really will expand the envelope of discrepancy in which orthodontic treatment can besuccessful.

It is clear that placement of a miniplate is a more complex procedure than that of a miniscrew.However, is this greater complexity warranted? It would seem that the greater flexibilityprovided by the current design of miniplates is an advantage in certain circumstances. Forexample, during en-masse movement of an entire arch by more than 2 mm, placing TSADsabove the root apices would be preferable.36,37 Miniplate systems that accept archwires alsoallow changes in the point of force application or force vectors without the need to repositionthe TSAD. As currently designed, miniplates seem to be associated with a lower failure ratethan miniscrews.16 The possibility raised by Liou et al18—that miniscrews do not remainstationary under orthodontic forces—suggests that a safety zone for root or nerve proximitymight be required. This could further restrict possible placement sites or limit the amount oftooth movement. For patients who are undergoing extensive orthopedic corrections or othertreatments (maxillary protraction or intrusion) when the TSADs are expected to be in place fora long time, the force vectors need to be varied, or the roots need to slide past the anchors, thenminiplates might be preferred. However, the relative effectiveness, efficiency, andacceptability to patients of different temporary anchorage devices used for various clinicalproblems need to be evaluated systematically.

CONCLUSIONSThis study was designed to explore patient and provider perceptions of the use of modifiedminiplates as TSADs. We concluded that miniplates are well accepted by patients andproviders, and offer safe and effective anchorage possibilities with a high success rate (92.5%),with few side effects or problems during treatment. Even novice users found miniplates to bothsimplify orthodontic treatment and enhance the possibility of treatments that might have beenconsidered unfeasible without skeletal anchorage. Although the surgery to place miniplates ismore invasive than for miniscrews, the patients experienced few undesirable sequelae, wereenthusiastic about their use, and appeared to regard their placement as a relatively trivial dentalevent. Details of the surgical placement and removal will be covered in a future study.

We thank Debbie Price for data management from both sites.

AcknowledgmentsSupported in part by a grants from the Southern Association of Orthodontists, the Dental Foundation of the Universityof North Carolina, and Universté catholique de Louvain (Fonds Spéciaux de Recherche 2004).

REFERENCES1. Creekmore TD, Eklund MK. The possibility of skeletal anchorage. J Clin Orthod 1983;17:266–269.

[PubMed: 6574142]2. Higuchi KW, Slack JM. The use of titanium fixtures for intraoral anchorage to facilitate orthodontic

tooth movement. Int J Oral Maxillofac Implants 1991;6:338–344. [PubMed: 1813401]3. Roberts WE, Marshall KJ, Mozsary PG. Rigid endosseous implant utilized as anchorage to protract

molars and close an atrophic extraction site. Angle Orthod 1990;60:135–152. [PubMed: 2344070]4. Wehrbein H, Merz BR, Diedrich P, Glatzmaier J. The use of palatal implants for orthodontic anchorage.

Design and clinical application of the orthosystem. Clin Oral Implants Res 1996;7:410–416. [PubMed:9151610]

5. Kanomi R. Mini-implant for orthodontic anchorage. J Clin Orthod 1997;31:763–767. [PubMed:9511584]

6. Jenner JD, Fitzpatrick BN. Skeletal anchorage utilising bone plates. Aust Orthod J 1985;9:231–233.[PubMed: 3870084]

Cornelis et al.


NIH


NIH


NIH


7. Freudenthaler JW, Haas R, Bantleon HP. Bicortical titanium screws for critical orthodontic anchoragein the mandible: a preliminary report on clinical applications. Clin Oral Implants Res 2001;12:358–363. [PubMed: 11488865]

8. Giancotti A, Arcuri C, Barlattani A. Treatment of ectopic mandibular second molar with titaniumminiscrews. Am J Orthod Dentofacial Orthop 2004;126:113–117. [PubMed: 15224068]

9. Hong RK, Heo JM, Ha YK. Lever-arm and mini-implant system for anterior torque control duringretraction in lingual orthodontic treatment. Angle Orthod 2005;75:129–141. [PubMed: 15747828]

10. Park HS, Kwon TG. Sliding mechanics with microscrew implant anchorage. Angle Orthod2004;74:703–710. [PubMed: 15529508]

11. Park HS, Kwon TG, Sung JH. Nonextraction treatment with microscrew implants. Angle Orthod2004;74:539–549. [PubMed: 15387034]

12. Park HS, Lee SK, Kwon OW. Group distal movement of teeth using microscrew implant anchorage.Angle Orthod 2005;75:602–609. [PubMed: 16097229]

13. Park YC, Lee SY, Kim DH, Jee SH. Intrusion of posterior teeth using mini-screw implants. Am JOrthod Dentofacial Orthop 2003;123:690–694. [PubMed: 12806352]

14. Poggio PM, Incorvati C, Velo S, Carano A. “Safe zones”: a guide for miniscrew positioning in themaxillary and mandibular arch. Angle Orthod 2006;76:191–197. [PubMed: 16539541]

15. Schnelle MA, Beck FM, Jaynes RM, Huja SS. A radiographic evaluation of the availability of bonefor placement of miniscrews. Angle Orthod 2004;74:832–837. [PubMed: 15673148]

16. Miyawaki S, Koyama I, Inoue M, Mishima K, Sugahara T, Takano-Yamamoto T. Factors associatedwith the stability of titanium screws placed in the posterior region for orthodontic anchorage. Am JOrthod Dentofacial Orthop 2003;124:373–378. [PubMed: 14560266]

17. Buchter A, Wiechmann D, Koerdt S, Wiesmann HP, Piffko J, Meyer U. Load-related implant reactionof mini-implants used for orthodontic anchorage. Clin Oral Implants Res 2005;16:473–479.[PubMed: 16117773]

18. Liou EJ, Pai BC, Lin JC. Do miniscrews remain stationary under orthodontic forces? Am J OrthodDentofacial Orthop 2004;126:42–47. [PubMed: 15224057]

19. Sugawara J, Daimaruya T, Umemori M, Nagasaka H, Takahashi I, Kawamura H, et al. Distalmovement of mandibular molars in adult patients with the skeletal anchorage system. Am J OrthodDentofacial Orthop 2004;125:130–138. [PubMed: 14765050]

20. Erverdi N, Keles A, Nanda R. The use of skeletal anchorage in open bite treatment: a cephalometricevaluation. Angle Orthod 2004;74:381–390. [PubMed: 15264651]

21. Sherwood KH, Burch JG, Thompson WJ. Closing anterior open bites by intruding molars withtitanium miniplate anchorage. Am J Orthod Dentofacial Orthop 2002;122:593–600. [PubMed:12490869]

22. Sugawara J, Baik UB, Umemori M, Takahashi I, Nagasaka H, Kawamura H, et al. Treatment andposttreatment dentoalveolar changes following intrusion of mandibular molars with application of askeletal anchorage system (SAS) for open bite correction. Int J Adult Orthod Orthognath Surg2002;17:243–253.

23. Cornelis MA, De Clerck HJ. Biomechanics of skeletal anchorage, part 1: Class II extraction treatment.J Clin Orthod 2006;40:261–269. [PubMed: 16636434]

24. Bengi AO, Karacay S, Akin E, Olmez H, Okcu KM, Mermut S. Use of zygomatic anchors duringrapid canine distalization: a preliminary case report. Angle Orthod 2006;76:137–147. [PubMed:16448284]

25. Erverdi N. A new anchorage site for the treatment of anterior open bite: zygomatic anchorage. Casereport. World J Orthod 2002;3:147–153.

26. Erverdi N, Acar A. Zygomatic anchorage for en masse retraction in the treatment of severe Class IIdivision 1. Angle Orthod 2005;75:483–490. [PubMed: 15898393]

27. Erverdi N, Usumez S, Solak A. New generation open-bite treatment with zygomatic anchorage. AngleOrthod 2006;76:519–526. [PubMed: 16637736]

28. Fukunaga T, Kuroda S, Kurosaka H, Takano-Yamamoto T. Skeletal anchorage for orthodonticcorrection of maxillary protrusion with adult periodontitis. Angle Orthod 2006;76:148–155.[PubMed: 16448285]

Cornelis et al.


NIH


NIH


NIH


29. Kircelli BH, Pektas ZO, Uckan S. Orthopedic protraction with skeletal anchorage in a patient withmaxillary hypoplasia and hypodontia. Angle Orthod 2006;76:156–163. [PubMed: 16448286]

30. Sherwood KH, Burch J, Thompson W. Intrusion of supererupted molars with titanium miniplateanchorage. Angle Orthod 2003;73:597–601. [PubMed: 14580029]

31. Umemori M, Sugawara J, Mitani H, Nagasaka H, Kawamura H. Skeletal anchorage system for open-bite correction. Am J Orthod Dentofacial Orthop 1999;115:166–174. [PubMed: 9971928]

32. Yao CC, Wu CB, Wu HY, Kok SH, Chang HF, Chen YJ. Intrusion of the overerupted upper left firstand second molars by mini-implants with partial-fixed orthodontic appliances: a case report. AngleOrthod 2004;74:550–557. [PubMed: 15387035]

33. Ari-Demirkaya A, Masry MA, Erverdi N. Apical root resorption of maxillary first molars afterintrusion with zygomatic skeletal anchorage. Angle Orthod 2005;75:761–767. [PubMed: 16283814]

34. Cheng SJ, Tseng IY, Lee JJ, Kok SH. A prospective study of the risk factors associated with failureof mini-implants used for orthodontic anchorage. Int J Oral Maxillofac Implants 2004;19:100–106.[PubMed: 14982362]

35. Gunduz E, Schneider-Del Savio TT, Kucher G, Schneider B, Bantleon HP. Acceptance rate of palatalimplants: a questionnaire study. Am J Orthod Dentofacial Orthop 2004;126:623–626. [PubMed:15520697]

36. Sugawara J, Kanzaki R, Takahashi I, Nagasaka H, Nanda R. Distal movement of maxillary molarsin nongrowing patients with the skeletal anchorage system. Am J Orthod Dentofacial Orthop2006;129:723–733. [PubMed: 16769490]

37. De Clerck HJ, Cornelis MA. Biomechanics of skeletal anchorage, part 2: Class II nonextractiontreatment. J Clin Orthod 2006;40:290–298. [PubMed: 16804241]

Cornelis et al.


NIH


NIH


NIH


Fig 1.Miniplates: A, maxillary and B, mandibular (Bollard; Surgitec, Bruges, Belgium); C, C-Tube(KLS Martin, Umkirch, Germany).

Cornelis et al.


NIH


NIH


NIH


Fig 2.Number of patients at the 2 centers receiving TSADs for various clinical conditions.

Cornelis et al.


NIH


NIH


NIH


Fig 3.A, Distalization of premolars and molars with open-coil spring placed between the anchor andthe sliding tube; B, maxillary protraction with Class III elastics placed between maxillaryposterior and mandibular anterior miniplates.

Cornelis et al.


NIH


NIH


NIH


Fig 4.Mean, median, and range of patients’ perceived pain after TSAD placement and duringorthodontic treatment and the degree of swelling reported one month after placement.

Cornelis et al.


NIH


NIH


NIH


Fig 5.Percentage of patients indicating TSAD better than other previously experienced dentalprocedures.

Cornelis et al.


NIH


NIH


NIH


Fig 6.Percentage of patients reporting side effects at various times.

Cornelis et al.


NIH


NIH


NIH


Fig 7.A, Mean, median, and range of orthodontists’ perceived difficulty of treatment with and withoutTSADs and the difficulty they experienced using TSADs; B, mean, median, and range oforthodontists’ reports of satisfaction with TSAD and side effects observed in patients.

Cornelis et al.


NIH


NIH


NIH


NIH


NIH


NIH


Cornelis et al.

Table IDemographics of patients receiving TSADs at 2 centers

UNC UCL

Patients (n) 30 67

Mean age (range) (y) 24.0 (12.2–48.1) 23.5 (9.8–46.9)

Females 73.3% 73.1%

Growing patients (females, ≤15; males, ≤19) 8 (27%) 24 (36%)

Patients with 1 implant 3 (10%) 17 (25%)

Patients with 2 implants 26 (87%) 38 (57%)

Patients with 3 implants 0 1 (2%)

Patients with 4 implants 1 (3%) 11 (16%)


NIH


NIH


NIH


Cornelis et al.

Table IIType, location, and failure of TSADs at the 2 centers

UNC UCL

Bollards 39 141

C-tubes 20 0

Maxilla posterior 49 104

Mandible anterior 6 32

Mandible posterior 4 5

Time to loading (d) 23.0 ± 19.6 34.7 ± 26.1

Total number of failures 4 11

Due to mobility 2 5

Due to soft-tissue ulceration 0 4

Due to anchor breakage 1 2

Due to poor location 1 0

In growing patients (females, ≤15; males, ≤19) 3 8

In adults 1 3

Maxilla 4 5

Mandible 0 6


author manuscript nih public access a, b, catherine nyssen

Documents