INTRODUCTIONTransposition is defined as an interchange in theposition of two teeth within the same quadrant of thedental arch. Maxillary canine-premolar transposition(MxC.P1) is the most frequent transposition andthe incidence is reported to be 0.135 - 0.510%.1

Transposition may affect both genders equally andshows higher maxillary prevalence. Although, the exactmechanism of canine transposition is unclear, a possibleexplanation for tooth transposition would be anexchange in position of developing tooth buds. However,the current data supports this disturbance to geneticinfluences within a multifactorial inheritance model.2,3

Treatment options for transposition include earlydiagnosis and guidance of eruption and orthodonticmanagement either by non-extraction or extractionmodalities.4

The authors report this uncommon condition as abilateral occurrence in a teen-aged girl.

CASE REPORTA girl aged 13 years and 2 months reported to theDepartment of Orthodontics with the chief complaint ofgap between teeth. She presented with good facialrelationships, and a slightly prominent chin. The patienthad permanent dentition, dental Class-I malocclusion,complete bilateral transposition of MxC.P1, mild upper

and lower labial segment crowding, crossbite of upperright lateral incisor with right lower canine, overjet of3 mm and overbite of 4 mm (Figure 1 and 2).Cephalometric analysis showed a mild skeletal Class-IIIrelationship (ANB angle = -1°) with low verticalproportions (FMA = 17°).

Treatment alternatives discussed with patient werecorrecting the order of transposed teeth, maintaining theorder of transposed teeth and extraction of one of thetransposed teeth.

As the patient’s facial profile was satisfactory, correctionof crowding and management of transposition was thetreatment objective. The treatment goals were tomaintain Class-I molar relationship, achieve ideal overjetand overbite, maintain the order of transposed teeth bysimulating maxillary first premolar as canine bilaterallyand achieve good facial balance.

The treatment plan, after considering the completenature of the transposition, facial profile, lip position,smile height, crowding and the cephalometric and dentalcast analyses was to improve the facial esthetics alongwith the dental relations. Therefore, a non-extractionfixed mechanotherapy treatment was consideredkeeping the transposed order of the teeth (by simulationof MxC.P1 bilaterally), upper and lower pre-adjustededgewise appliances (0.022” x 0.028” slot) with Rothprescription.

Treatment was initiated by banding of permanent firstmolars, during the bonding procedures canine bracketwas bonded onto first premolar crown to achieve thecanine prominence and the palatal cusp of maxillary firstpremolars were grinded. Leveling and alignment wasstarted with 0.012” NiTi wire and was carried upto 0.016”NiTi archwire and then 0.018” stainless steel was placed

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CASE REPORT

Bilateral Maxillary Canine-First Premolar Transposition in Permanent Dentition

Sarwat Memon and Mubassar Fida

ABSTRACTTransposition is a dental anomaly characterized by the exchange of position between two adjacent teeth, especially inrelation to their roots, or development and eruption of a tooth in a position normally occupied by a nonadjacent tooth.Transposition of the maxillary canine and first premolar has a low prevalence in the population and it primarily affectsmaxillary canines and premolars. The aetiology of the transposition remains unclear, although it has been associated withgenetic factors. It may also be related to a combination of localised factors such as malformation of adjacent teeth, toothagenesis, retention of the deciduous canine and a history of local trauma. If uncorrected, the results are often bothfunctionally and esthetically unsatisfactory. This case report presents treatment of a female patient with complete bilateraltransposition of maxillary canine and premolar. The patient was treated orthodontically with non-extraction fixedmechanotherapy by simulation of maxillary first premolar as canine bilaterally.

Key Words: Bilateral maxillary canine-first premolar. Transposition. Permanent dentition.

Section of Dentistry, Department of Surgery, The Aga KhanUniversity Hospital, Karachi.

Correspondence: Dr. Sarwat Memon, Assistant ProfessorOrthodontics, Ziauddin College of Dentistry, Karachi.E-mail: sarwatmaqsood@yahoo.com

Received: January 21, 2013; Accepted: July 09, 2013.

Sarwat Memon and Mubassar Fida

598 Journal of the College of Physicians and Surgeons Pakistan 2014, Vol. 24 (8): 597-599

with open coil spring bilaterally between maxillary lateralincisors and canines to create space for maxillary firstpremolars. The canine was bonded with first premolarbracket and aligned into arch. Upper and lower 0.017 x0.025” stainless steel wire were inserted, buccal roottorque and mesiopalatal rotation bends were given onsimulated canines (first premolars). Finally, pre-debondOPG was evaluated for root paralleling bends andsettling elastics were given.

Posttreatment facial photographs showed a pleasantsmile. The favourable soft tissue drape facilitatedorthodontic camouflage of the Class-III skeletal pattern,without detriment to dentofacial appearance. Lips werecompetent at the end of treatment, with the upperincisors under the control of the lower lip. However, thelower lip appeared full but it is normal in patients withskeletal Class-III malocclusion The maxillary caninesand first premolars were successfully aligned into archmaintaining the order of transposed teeth. The case wasfinished in Class-I molars on both sides (Figure 3 and 4).The lower incisors were advanced marginally withtreatment to relieve the crowding, risking their antero-posterior stability. However, overbite was minimal,interproximal reduction in the lower labial segment wouldhave prevented this, and possibly increased the overbitefurther. However, fixed upper and lower bonded retainerwas given to the patient in order to enhance stability.

DISCUSSIONThe maxillary permanent canine tooth is the mostfrequently involved in transposition. The canine showshighest incidence of transposition with first premolar.Although transpositions are associated with increasedfrequency of other dental anomalies, supporting agenetic etiology, however, there are no other dentalanomalies in the case presented here. Thus, etiology oftransposition of present case is not clear.

Figure 1: Pre-treatment photographs: (A) Extra-oral (B) Intraoral.

Figure 2: Pre-treatment: (A) Lateral cephalograph (B) Orthopantomograph.

Figure 3: Post-treatment photographs: (A) Extra-oral (B) Intraoral.

Figure 4: Post-treatment: (A) Lateral cephalograph (B) Orthopantomograph.

Transposition of MxC.P1 allows three main options to beconsidered. When the sufficient space cannot be gainedto align the transposed teeth, then only extraction oftooth should be considered. For this case, extractiontreatment was not considered as there was no archlength deficiency. It was not advised to correcttransposed teeth in the permanent dentition becauseattempts at restoring the natural tooth order usuallyleads to root resorption, labial bone dehiscence. Whilemoving the teeth across each other, vitality of the toothmay be affected if its root is moved out of bone supportwhile moving it across the transposed tooth andtreatment time may be prolonged.5

In this case, a non-extraction treatment was considered.Therefore, keeping the transposed order of the teeth orrecreating the natural tooth order was presented as thetwo treatment alternatives to the patient. In incompletetranspositions, where the crowns are transposed but theroots are in normal position, uprighting and rotating theinvolved teeth is the procedure undertaken to placethem in normal alignment provided sufficient space isavailable in the arch.5,6 Furthermore, when thetransposition is complete with tooth apices in transposedposition, repositioning the teeth to the normal position inthe arch is complex and may be damaging to the teethand supporting structures. Alignment of teeth to thetransposed order is the best option.8 Hence, in thepresent case of bilateral complete transpositions ofMxC.P1, alignment of the teeth in their transposedpositions with reshaping of their incisal surfaces gave anacceptable esthetic result. The patient and her parentswere extremely satisfied with the results.

Deepti et al. reported a case of complete transposition ofthe maxillary canines with the permanent lateral incisorarea in which they maintained the order of transposedteeth and then reshaped them for the purpose ofesthetics purpose.9 Maia and Maia10 also reported thenon-extraction management of a bilateral MxC.P1transposition with congenitally missing lateral incisors.They showed a small degree of root resorption on thecanines and central incisors, and a small loss of alveolarcrest height. Although great effort was made to prevent

root resorption, minor root contour irregularities occurredat the maxillary premolars at the end of treatment.

The prevalence of tooth transposition is low, but themanagement of transposed teeth especially MxC.P1,must be assessed on case-to-case basis. This type ofdental anomaly causes many problems in orthodonticmanagement, many factors that affect the treatmentresults must be considered, such as esthetics,occlusion, treatment period, patient comfort, patient co-operation, and periodontal support. However, it ispossible to orthodontically treat this challenginganomaly in an efficient way and achieve promisingresults. This may also provide orthodontists with the bestunderstanding of how to resolve similar malocclusions inthe future.

REFERENCES1. Kuttupa N, Nayak US, Shetty A, Murali S. Bilateral maxillary

canine: premolar transposition. J Ind Orthod Soc 2011; 45:193-7.

2. Capelozza Filho L, Cardoso Mde A, An TL, Bertoz FA.Maxillary canine: first premolar transposition. Angle Orthod2007; 77:167-75.

3. Qamara Ch, Riaz M. Transposition of teeth: a review ofliterature. POJ 2010; 2:72-5.

4. Burki S, Munawwar S. Maxillary tooth transposition: a review ofthe literature. Pak Oral Dent Jr 2004; 24:61-3.

5. Kapoor P. Transposition of bilateral maxillary canine and firstpremolar. Int J Orthod Milwaukee 2010; 21:37-41.

6. Hudson AP, Harris AM, Mohamed N. Maxillary caninemanagement in the pre-adolescent: a guideline for generalpractitioners. SADJ 2010; 65:368-70.

7. Sabri R, Zaher A, Kassem H. Tooth transposition: a review andclinical considerations for treatment. World J Orthod 2008; 9:303-18.

8. Vitale C, Militi A, Portelli M, Cordasco G, Matarese G. Maxillarycanine: first premolar transposition in the permanent dentition.J Clin Orthod 2009; 43:517-23.

9. Deepti A, Rayen R, Jeevarathan J, Muthu MS, Rathna PV.Management of an impacted and transposed maxillary canine.J Indian Soc Pedod Prev Dent 2010; 28:38-41.

10. Maia FA, Maia NG. Unusual orthodontic correction of bilateralmaxillary canine-first premolar transposition. Angle Orthod2005; 75:262-72.

Bilateral maxillary canine-first premolar transposition in permanent dentition

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