attempted traction of impacted and ankylosed …attempted traction of impacted and ankylosed...

CASE REPORT

Attempted traction of impacted and ankylosedmaxillary canines

Marlio Vin�ıcius de Oliveiraa and Matheus Melo Pithonb

Minas Gerais and Bahia, Brazil

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The aim of this article is to report the clinical orthodontic treatment of an adult patient with 2 impacted maxillarycanines. Traction was applied to the impacted teeth; however, after 7 months, the teeth were found to beankylosed and were extracted. The extraction spaces were closed by moving the posterior teeth mesiallywith mini-implant anchorage. The results were satisfactory, with the premolars in the functional position of thecanines. (Am J Orthod Dentofacial Orthop 2012;142:106-14)

The maxillary canines are important teeth in termsof esthetics and function. The likelihood of theirfailing to erupt or becoming impacted is between

1% and 3%.1,2 The causes of canine impaction can becorrelated with other dental anomalies and could bedue to local factors or a polygenetic, multifactorialinheritance. Local factors are tooth size-arch lengthdiscrepancies, prolonged retention or early loss of thedeciduous canine, abnormal tooth bud position, alveolarcleft, dilaceration of the root, and idiopathic conditionswith no apparent cause.3 This problem has severalsolutions.

The impacted tooth could be extracted, autotrans-plantation could be performed, or the tooth could besurgically exposed and orthodontically moved toanother position in the dental arch. The timing oforthodontic treatment, the type of surgical procedureto expose the impacted tooth, the necessary orthodonticmechanics, and potential problems with treatment vary,depending on which tooth is impacted and its position inthe jaw.4

The objective of this case report is to describe thetreatment of an adult with 2 impacted maxillary canines,

ialist in orthodontics, Alfenas Pharmacy and Dental School, Efoa/Ceufe, Al-, Minas Gerais, Brazil; Diplomate of Brazilian Board of Orthodontics andfacial Orthopedics.ssor, Southwest Bahia State University, UESB, Bahia, Brazil; doctor of or-ntics at the School of Dentistry, Federal University of Rio de Janeiro-UFRJ,; Diplomate of Brazilian Board of Orthodontics and Dentofacial Orthope-

uthors report no commercial, proprietary, or financial interest in the prod-r companies described in this article.t requests to: Matheus Melo Pithon, Av Ot�avio Santos, 395, sala 705, Cen-ontom�edico Dr, Altamirando da Costa Lima, Vit�oria da Conquista, Bahia,, CEP: 45020-750; e-mail, [email protected], May 2010; revised and accepted, September 2010.5406/$36.00ight � 2012 by the American Association of Orthodontists..1016/j.ajodo.2010.09.037

which were diagnosed as ankylosed after the attempt toerupt them failed. This required extraction of the caninesand orthodontic closure of the extraction spaces.

DIAGNOSIS AND ETIOLOGY

At the initial examination, the patient was aged 25years 5 months and in a good state of general health.She was referred to the orthodontist for orthodontictreatment by her general dentist, who found the 2impacted maxillary canines (Fig 1).

The patient had an Angle Class I malocclusion andan arch length discrepancy of –8.5 mm in the mandibu-lar arch. Both maxillary canines were impacted, and themandibular incisors were retroclined (1.NB, 16�). Therewere normal overlap and overbite, and quadrangular-shaped arches, with symmetry in the anteroposteriorand transverse directions (Figs 1 and 2).

Radiographically, the impaction of the maxillarycanines and mandibular third molars could be observed(Fig 3). The cephalometric radiograph showed a smallskeletal disharmony in the sagittal direction, with anANB angle equal to 0� (SNA, 84�; SNB, 84�). This showeda tendency for a skeletal Class III relationship. In thevertical plane of space, all cephalometric measurementsindicated a well-balanced face (Go Gn-Sn, 30�; y-axis,62�; FMA, 30�) (Figs 3 and 4).

The facial analysis showed a balanced and harmoni-ous face, with lip seal at rest, a straight profile witha slight protrusion of the bottom lip (top lip, S-line,0 mm; bottom lip, S-line, 2 mm) and an acceptablenasolabial angle (Figs 1 and 4).

TREATMENT OBJECTIVES

1. Maxilla: maintain the vertical, anteroposterior, andtransverse positions.

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Fig 1. Pretreatment photographs.

Fig 2. Pretreatment dental casts.

de Oliveira and Pithon 107

2. Mandible: maintain the maxillomandibular rela-tionship during orthodontic treatment.

3. Maxillary teeth: extract the deciduous canines andattempt traction of the impacted permanent

American Journal of Orthodontics and Dentofacial Orthoped

canines. If the canines respond well to traction, itwould be necessary to extract the first premolars.If the canines are ankylosed, they would be replacedby the first premolars.

ics July 2012 � Vol 142 � Issue 1

Fig 3. Pretreatment radiographs.

108 de Oliveira and Pithon

4. Mandibular teeth: extract the first premolars to ob-tain space for alignment and leveling of the caninesand the incisors. Maintain the retroclination of theincisors during treatment (1.NB, 16�).

5. Occlusion: establish proper canine occlusion,correct the mandibular crowding, obtain simulta-neous bilateral contacts in harmony with centricrelation, and disclude the posterior teeth in mandib-ular excursive movements.

6. Facial esthetics: in conjunctionwith the patient's de-sires, the option was for treatment with extractionsinstead of orthognathic surgery, knowing the possi-bility of flattening the facial profile.

TREATMENT ALTERNATIVES

1. Orthosurgical treatment, with extraction of themaxillary first premolars to achieve better

July 2012 � Vol 142 � Issue 1 American

positioning of the maxillary incisors in addition toeruption and proper positioning of the maxillarycanines.

2. Orthodontic treatment with extraction of the 4 firstpremolars and orthodontic repositioning of themaxillary canines.

3. Attempt traction of the maxillary left and rightcanines and maintain the maxillary left andright first premolars, without initially extractingthem. If the canines responded to treatment favor-ably, the premolars would be extracted.

4. Treatment associated with extraction of all 4 firstpremolars.

TREATMENT PROGRESS

The patient declined orthognathic surgery becauseshe had no esthetic complaints regarding her face.

Journal of Orthodontics and Dentofacial Orthopedics

Fig 4. Pretreatment cephalometric tracing.


Therefore, in conjunction with the patient, we decidedto extract the 4 first premolars. The patient wasinformed with respect to the possible ankylosis of themaxillary canines and also that attempts to movethem would lead to an increased treatment time. Inthe maxillary arch, initially only the deciduous canineswere extracted, because if traction of the permanentcanines was unsuccessful, the first premolars couldreplace them.

The plan was to place fixed orthodontic appliancesin the maxillary and mandibular dental arches byusing conventional edgewise brackets with 0.022 30.028-in slots, except for the mandibular incisors,which initially were not moved until there was spacefor aligning and leveling after partial retraction ofthe canines.

In the maxillary arch, stainless steel archwires, from0.014 to 0.020 in, were used for alignment and leveling.After this, the maxillary deciduous canines wereextracted, and surgical uncovering of the permanentcanines was performed. A stainless steel arch was madeof a rectangular section of 0.019 3 0.025-in archwire,with first- and third-order bends. Helical springs werewelded between the lateral incisors and the firstpremolars, and a force of 100 g was applied to thecanines (Fig 5). After 7 months of traction, opening ofthe bite in the incisor region was verifiedradiographically (Fig 6), and the canines were in thesame position (Fig 7). Therefore, extraction of theseteeth was requested, and the first premolars were usedto replace them.


Orthodontic mini-implants were placed distally tothe maxillary lateral incisors and were used to movethe maxillary posterior teeth mesially (Fig 8). Theseserved as added anchorage for the nickel-titaniumsprings. In the mandibular arch, partial retraction ofthe canines was performed with a segmented stainlesssteel archwire, 0.018 3 0.025 in, that was passive onthe molars and premolars, with a T-loop between thecanines and the second premolars. After partial retrac-tion of the canines, round stainless steel archwires of0.016 to 0.020 in were used, with box loops on thecanines, to correct the root positions. By tying the molarsand canines together, mesial inclination of their crownswas prevented. In the next phase, the incisors werebonded; stainless steel archwires of 0.014 to 0.020 inwere made for alignment and leveling of all teeth.

In sequence, retraction arches of 0.019 3 0.025in were used, with loops to retract the anterior teeth.In the maxillary arch, the loops were located betweenthe lateral incisors and the first premolars. In themandibular arch, they were located between the caninesand the second premolars.

Maxillary and mandibular rectangular arches of0.019 3 0.025 in were used to finalize the toothpositions, with first- and third-order bends accordingto the requirements of the teeth. After the activetreatment phase, a removable maxillary circumferentialretainer and a mandibular lingual bonded retainerwere used to maintain the tooth positions.

TREATMENT RESULTS

The posttreatment records show a satisfactory treat-ment result (Figs 9-13).

1. Maxilla: there was a reduction of 1� in the SNAangle, probably due to alveolar remodeling, duringretraction of the incisors. Its vertical and transversepositioning was maintained.

2. Mandible: the vertical, anteroposterior, and trans-verse positions were maintained.

3. Maxillary teeth: extraction of the permanentcanines was necessary because they were ankylosed.The first premolars were used to replace the canines.

4. Mandibular teeth: space was obtained for aligningand leveling the incisors and canines by extractionof the first premolars. Incisor retroclination wasmaintained to enable adequate overlap andoverbite, since the patient had a slight skeletal ClassIII (final ANB, –1�).

5. Occlusion: in the maxillary arch, the first premolarswere positioned in the place of the canines. Idealfunctional occlusion was obtained.


Fig 5. Intraoral photographs during the traction.

Fig 6. Intraoral photographs demonstrating intrusion of the maxillary teeth during the unsuccessfulattempt to erupt the 2 maxillary canines.

Fig 7. Progress panoramic radiograph. The bite had opened, and the canines remained impacted.


6. Facial esthetics: in spite of the slight deepening ofthe facial profile (top lip, S-line was reduced by2 mm; bottom lip, S-line was reduced by 3 mm),facial esthetics were not compromised.

DISCUSSION

The maxillary canines are the most frequentlyimpacted teeth (except for the third molars). Accordingto Dewel,5 the maxillary canines have the longestdevelopment period, as well as the longest and mosttortuous route from the point of formation to their final


destination in full occlusion. Most clinicians agree thatthe permanent canines are essential for a functionalocclusion, and that they play a major role in an attractivesmile. For this reason, an orthodontist's main task is toalign impacted canines.6

The prognosis of treatment in these patients dependson the position of the canine in relation to the adjacentteeth and their height in the alveolar process.4 Oneshould also consider the possibility that the impactedcanine will not move orthodontically. Then its extractionwill be necessary, and the space could be occupied by thepremolar or an implant or a pontic. The objective of this


Fig 8. Progress intraoral photographs. Mini-implants were placed distally to the maxillary lateral inci-sors and used to move the maxillary posterior teeth mesially.

Fig 9. Posttreatment photographs.


article is to describe the orthodontic treatment of a pa-tient with 2 impacted maxillary canines that wereankylosed when an attempt was made to move them.

Before starting treatment to orthodontically moveimpacted teeth, it is always important for patients or


their parents to be aware of the advantages and risksof treatment: ankylosis, loss of tooth vitality, resorp-tion of the roots of the canine and adjacent teeth,loss of periodontal support, and a long treatmenttime. According to Cappellette et al,7 a canine in


Fig 10. Posttreatment dental casts.

Fig 11. Posttreatment radiographs.


a patient between the ages of 13 and 19 years canfrequently be brought into the arch by orthodontictraction after surgical exposure. In older patients, thereis an increased risk that the impacted tooth could beankylosed.


There are 3 techniques for accessing labiallyimpacted maxillary canines: simply excising the gingiva,apical positioning of a gingival flap, and theclosed-eruption technique.8 In our patient, the closed-eruption technique was chosen, because the crown of


Fig 12. Posttreatment cephalometric tracing.

Fig 13. Superimposed cephalometric tracings.


the canine was well above the mucogingival line. Theapically positioned flap technique was not selected,because it could result in reintrusion of the canine afterorthodontic treatment and could also increase thepossibility of gingival recession.

When extraction of a first premolar is indicated toobtain space for an impacted canine, it is advanta-geous to avoid extraction until the possibility of


ankylosis or other problems—dilaceration or rootresorption of the canine—have been assessed. In ourpatient, all of these precautions were taken. About 7months after the attempt to move the impactedcanines, we observed an opening of the bite causedby intrusion of the incisors. Radiographically, a falseimpression was gained that the canines had descended.However, in reality, the incisors had intruded. Whenthis was identified, canine traction was suspended,and the patient was referred for extraction of thecanines. During the surgery, the surgeon confirmedankylosis of the canines because of the difficulty ofextracting them; it was necessary to section these teethto remove them.

It was important that the premolars were not prema-turely extracted, so that they could be moved mesiallywith mini-implants that served as anchors. With theadvent of orthodontic mini-implants, many situationsthat were previously difficult to resolve have becomereal possibilities. With these mechanics, mesialmovement of the posterior teeth was achieved withoutretroclination of the incisors, which would have beenunfavorable in this patient, because of her facial profile.

When the canines are replaced, the working excur-sion of the mandible must be in group function, sincethe premolar buccal cusp is often too short. In thispatient, lateral disclusion was established with themaxillary first and second premolars contacting themandibular canines and first premolars (Fig 14). Whencanines are replaced by premolars, previous researchdoes not show evidence of periodontal problems in thelong term.9

When we examined the radiographs at the end oftreatment, there appeared to be proximity of the rootsof the incisors. Some authors have suggested thatadequate space between the roots of teeth at thebone-crest level is necessary for maintaining gingivalhealth. Therefore, when roots are in close proximity, itresults in thin interproximal bone, which could predis-pose the teeth to lose periodontal attachment morerapidly if the patient develops periodontal disease.10 Astudy that evaluated the incidence and distribution ofroot proximity after orthodontic treatment and alsotested the hypothesis that areas with thin interdentalbone septum are less resistant to periodontal diseasethan areas with normal bone dimensions between theroots of teeth concluded that there was no statisticaldifference in the quantity of gingival inflammation,attachment level, and bone level between the areaswith close roots and the control areas. The resultsalso showed that anterior teeth with close roots werenot more subject to gingival recession than were teethwith adequate interradicular space.


Fig 14. A, Anterior guidance; B and C, lateral disclusion through group function.


CONCLUSIONS

With the procedures performed for this patient, thefollowing can be concluded.

1. When the treatment plan involves orthodonticalignment of impacted canines, and it is necessaryto extract premolars to obtain space, extractionshould be delayed until after the impacted teethhave been successfully moved into the oral cavity.

2. Orthodontic mini-implants greatly facilitate mesialmovement of posterior teeth.

3. The replacement of canines by premolars is a feasiblealternative when there is ankylosis of the impactedcanines.

REFERENCES

1. Bishara SE. Clinical management of impacted maxillary canines.Semin Orthod 1998;4:87-98.

2. Tausche E, Harzer W. Treatment of a patient with Class II maloc-clusion, impacted maxillary canine with a dilacerated root, and


peg-shaped lateral incisors. Am J Orthod Dentofacial Orthop2008;133:762-70.

3. BedoyaMM, Park JH. A review of the diagnosis andmanagement ofimpacted maxillary canines. J Am Dent Assoc 2009;140:1485-93.

4. Peerlings RH. Treatment of a horizontally impacted mandibularcanine in a girl with a Class II Division 1 malocclusion. Am J OrthodDentofacial Orthop 2010;137(Suppl):S154-62.

5. Dewel BT. The upper cuspid: its development and impaction.Angle Orthod 1949;19:79-90.

6. van der Zwan J, van Beek H. The impacted upper cuspid. NedTijdschr Tandheelkd 1991;98:431-3.

7. Cappellette M, Cappellette M Jr, Fernandes LCM, Oliveira AP,Yamamoto LH, Shido FT, et al. Palatine impacted permanentmaxillary canines: diagnose and therapeutics. R Dent PressOrtodon Ortop Facial 2008;13:60-73.

8. Kokich VG. Surgical and orthodontic management of impactedmaxillary canines. Am J Orthod Dentofacial Orthop 2004;126:278-83.

9. Nordquist GG, McNeill RW. Orthodontic vs restorative treatment ofthe congenitally absent lateral incisor—long-term periodontal andocclusal evaluation. J Periodontol 1975;46:139-43.

10. �Artun J, Kokich VG, Osterberg SK. Long-term effect of rootproximity on periodontal health after orthodontic treatment. AmJ Orthod Dentofacial Orthop 1987;91:125-30.


attempted traction of impacted and ankylosed …attempted traction of impacted and ankylosed...

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