Unusual Orthodontic Correction of Bilateral Maxillary Canine First Premolar Transposition

Clinical Report Unusual Orthodontic Correction of Bilateral Maxillary Canine First Premolar Transposition Francisco Ajalmar Maia, DDS, MS, PhD a ; Nair Galvão Maia, DDS, MS b Abstract: Tooth transposition is a subject that intrigues orthodontists because of the associated treatment planning. Approximately 0.3 0.4% of the population has this type of tooth disharmony, and in the literature, most authors are in disagreement about the treatment approach. In this article, a case is presented of bilaterally maxillary canine first premolar transposition associated with bilaterally upper lateral incisor agenesis treated in a very unusual way. The transposed teeth were orthodontically reversed to their normal sequence and the missing lateral incisor spaces closed. We choose this approach because once the decision was made to close the upper lateral incisor agenesis spaces, it was inadequate to position the upper first premolars in contact with the central incisors. (Angle Orthod 2005;75:266 276.) Key Words: Transposition; Tooth transposition; Dental transposition; Tooth agenesis INTRODUCTION Transposition of teeth is a rare condition, with a prevalence of about 0.3 0.4% in the general population. 1 4 It is an eruption anomaly characterized by a change in position of two adjacent teeth. 1,5 Usually, transposition involves the canine and the first premolar 4,6 8 or lateral incisor, 1,2,4,9 11 but transposition of the central incisors has also been reported. 12 14 Five different types of transposition have been described in the upper arch 4,5 and only two in the lower arch. 15 Transposition can occur on both sides or only one, 6,7,16 18 with the left side more commonly affected in both sexes. Transposition is considered real or complete when the teeth have totally exchanged their position in the arch and their roots are parallel to each other. 2,3,9 It is called partial or incomplete when the tooth positions are not completely exchanged. 2,3,9 The diagnosis of transposition should not be confused with simple ectopic eruption. All transpositions are ectopic eruptions, but only a few ectopic eruptions may be considered transpositions. 1 In canine lateral incisor transposition cases, the position of the canine root apex a Professor of Orthodontics, Universidade Estadual da Paraiba, Campina Grande, PB, Brazil; Professor of Orthodontics, Universidade Potiguar and Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Chairman of Orthodontics, Centro de Ortodontia Integrado, Natal, RN, Brazil. b Professor of Orthodontics, Universidade Potiguar and Universidade Federal do Rio Grande do Norte, Natal, RN, Brazil; Practical Ortodontic, Centro de Ortodontia Integrado, Natal, RN, Brazil. Corresponding author: Francisco Ajalmar Maia, Rua Manoel Machado 683, Petropolis, Natal, RN 59012320, Brazil (e-mail: coi@digi.com.br). Accepted: April 2004. Submitted: February 2004. 2005 by The EH Angle Education and Research Foundation, Inc. should be mesial to the lateral incisor, and in canine first premolar cases, it should be distal to the first premolar. 12 Other dental abnormalities, frequently associated with the transposition phenomenon, are missing or peg-shaped upper lateral incisors, retention of deciduous canines, tooth rotation, and malposition of adjacent teeth. 2,3,8 10 Pathopaleontological findings have shown the presence of tooth transposition in prehistoric man in Southern Asia and North America, 15,19,20 so it cannot be considered a disharmony of modern times. Although the causes of transposition have not yet been completely established, many theories have been suggested to explain this process. Trauma, 2,21 retention or early loss of primary teeth, 22 transposition of the anlage of the teeth during odontogenesis, 2,23 and intraosseous migration of teeth away from their normal path of eruption 23,24 have all been considered to be causative factors. Peck and Peck 4 reported that in canine first premolar transposition, retention, trauma, and early loss of primary teeth were not considered relevant factors. Some authors 16,17,23,25 described nearly identical bilateral transpositions in siblings and have considered genetic factors responsible for tooth transposition. Recent evidence has shown a genetic influence within a multifactorial inheritance model, and the high frequency of associated dental anomalies plus family and bilateral occurrences support the case for polygenic causes. 4 The upper permanent canine develops under the orbit in a superior and palatal relation to the first premolar and lateral incisor. During its long path of eruption, the canine moves labially and mesially and can be palpated high in the labial sulcus. 26 For some reason, it can turn away from its path either mesially or distally, creating the possibility for transposition. 13 266

TRANSPOSITION OF TEETH 267 FIGURE 1. Initial intraoral photographs in frontal view (a) right side; (b) anterior; and (c) left side showing a Class I molar and canine relationship and normal overbite and overjet. (d) The upper arch occlusal view shows the primary lateral incisor retention. (e) The lower arch occlusal view shows anterior primary crowding. The extraoral (f) frontal and (g) lateral views exhibit a convex and harmonious profile, without strain in lip closure. (h) A pleasant smile. FIGURE 2. Initial (a, b, c) periapical radiographs and (d) panoramic radiograph showing bilateral maxillary permanent lateral incisors agenesis, upper lateral deciduous retention, and complete bilateral transposition of 13 and 14 and 23 and 24 teeth, normal periodontal support, and healthy bone. The most common type of tooth transposition is that of the upper canine first premolar. Usually the canine is rotated in a mesiobuccal direction, and the first premolar is tipped distally and rotated mesiopalatally. The upper deciduous canine is often present, creating an arch length discrepancy problem. 4 The canine is usually blocked out to the buccal between the first and second premolars, but in some cases it can be seen in a palatal position, especially in cases of canine and lateral incisor transposition. 10 Although several reports on maxillary canine and first premolar transposition can be found in the literature, very few include treatment procedures. 5,10,11 Several authors showed orthodontically treated cases that maintained the transposed teeth in their original positions. 6,7,14,27,28 Only one

268 AJALMAR MAIA, GALVÃO MAIA Case presentation FIGURE 3. Initial cephalometric tracing and measurements. article presented a case of bilateral canine and first premolar transposition, with missing lateral incisors, that was treated by reversing the transposed teeth. This was done only on the right side, and the primary canine was maintained in the lateral incisor position. 18 In this article, a case of maxillary bilateral canine first premolar transposition with missing lateral incisors was treated orthodontically by reversing the transposed teeth on both sides of the arch and closing the lateral incisor spaces. This approach was justified by the undesirability of having the first premolar in contact with the central incisors. A nine-year, five-month-old female patient presented with parents who were worried about the delayed eruption of the permanent lateral incisors. The patient was in the mixed dentition and presented a Class I molar and canine malocclusion with slight lower anterior crowding. She also presented regular oral hygiene and healthy periodontal tissues. The facial profile was convex, showing no muscle strain or pressure, and lip closure was normal with a pleasant smile (Figure 1). Panoramic and periapical radiographs showed the bilateral absence of the upper lateral incisors and the transposition of both upper canines with the first premolars (Figure 2). Both canines were located between the first and second premolars. The cephalometric measurements showed a vertical growth tendency (Figure 3; Tables 1 and 2). No cephalometric or dental discrepancy was present (Table 2). Facial convexity was greater than normal, which was favorable in missing lateral incisor cases when planning to close the spaces of the missing teeth. The radiographic and clinical evaluation indicated a very early stage of development to start treatment. However, treatment planning for correction of the transposed teeth and closure of the missing lateral incisor spaces was possible (Figures 4 8). The upper deciduous second molars (55, 65) and deciduous lateral incisors (52, 62) were removed, allowing closure of the missing lateral incisor spaces and mesial movement of the permanent upper first molars to a Class II relationship (Figures 6b,c). The upper deciduous canines and deciduous first molars (53, 63, 54, 64) were removed three months later to correct the transposition (Figures 6d). TABLE 1. Initial and Final Ricketts 10 Factors Analysis Data a Factor Measurements Initial Normal Clinic Deviation Clinical Measurements Final Normal Clinic Chin 1 2 3 5 6 Facial axis () Facial depth () Mandibular plane () Lower facial height () Mandibular arch () 85.3 82.6 31.1 43.1 27.3 90 87 26 47 26 3 3 4 4 4 83.9 85.8 30.5 44.9 33.2 90 89 24 47 29 Maxilla 7 Facial convexity (mm) 4.1 2.0 2 7.4 0 Teeth 8 9 10 Profile T-APO (mm) T-APO () 6-PTV (mm) 2.2 18.6 8.4 11 Labial protrusion (mm) 0.9 2.0 2 1.7 2.5 a F.C.S.L. (COI-2814). Initial: 9 y 5 mo. Final: 14 y 11 mo. 3.0 22 12 2 4 3 2.4 20 19.3 3.0 22 18

TRANSPOSITION OF TEETH 269 TABLE 2. Initial and Final Facial Descriptions (Facial Pattern Dolicho, Meso, or Brachi), Discrepancies, and SNA and SNB angles a,b Initial Final Factor Deviation Clinical Normal Clinic Dolicho Meso Brachi Measurements Measurements Normal Clinic Dolicho Meso Brachi 1 Facial axis () 2 Facial depth () 3 Mandibular plane () 4 Lower facial height () 5 Mandibular arch () Face description 3 3 4 4 4 85.3 82.6 31.1 43.1 27.3 90 87 26 47 26 86.9 85.8 30.5 44.9 33.2 Malocclusion Class I Class II Facial type Dolichofacial tendency Mesofacial Function Normal Normal SNA 76.9 Retrusion 81.4 Normal SNB 73.1 Retrusion 74.7 Retursion DD 0 CD 0 TD 0 a F.C.S.L. (COI-2814). Initial: 9 y 5 mo. Final: 14 y 11 mo. b DD, dental discrepancy; CD, cephalodiscrepancy; TD, total discrepancy. 90 89 24 47 29 FIGURE 4. Periapical maxillary (a) right and (b) left sides and (c) panoramic radiographs showing the premolars eruption and the start of treatment with orthodontic fixed appliance. A straight-wire 0.018 0.025 inch fixed appliance was placed when the patient was 10 years, two months old and the upper premolars were erupting (Figures 4 and 6e). The treatment plan consisted of reversing the transposed teeth, moving the upper first premolars palatally (Figure 6f) to allow the canines to move mesially through the alveolar bone, avoiding contact with the maxillary labial cortical bone. The upper canines were moved mesially as far as possible inside the alveolar bone toward the lateral incisor spaces (Figures 5 and 6g), whereas leveling and alignment

270 AJALMAR MAIA, GALVÃO MAIA FIGURE 5. (a, b) Intraoral view of the treatment progress showing the transposition reversal. The upper first premolars were moved palatally (Figure 6e), permitting the canines to be moved mesially through the alveolar bone preserving the labial cortical. were done with round 0.014 to 0.018 inch stainless steel archwires. Considering the limitations presented by the case, the follow-up records show a very good result because all treatment goals were fulfilled. Only a small amount of alveolar crest bone height was lost, and only a clinically insignificant amount of root resorption could be seen on the final FIGURE 7. Intraoral view (a, b, c) showing an 0.018 0.025 inch ideal arch with lingual root torque on the upper canines and labial root torque on the upper first premolars. FIGURE 6. The upper arch of the patient illustrates the mechanical sequence for reversing the transposition. (a) The original condition. Deciduous removal (b 55, 65), (c 52, 62), (d 54, 53, 63, 64). (e) Premolar eruption, and the start of the treatment with fixed appliance. (f) The left and right first premolars were moved palatally to allow the canines to be moved mesially through the alveolar bone. (g) The canines were brought mesially to the first premolars, which will be moved back to the alveolar arch. (h) Mesial movement of the molars, premolars, and canines, bilaterally, and remaining space closure.

TRANSPOSITION OF TEETH 271 FIGURE 8. Intraoral photographs at the conclusion of the treatment (a, b, c) showing transposition correction, the upper canines moved to the missing lateral spaces, and all the upper teeth brought to mesial position. (d) Upper arch occlusal view showing the arch shape. (e) Lower arch occlusal view showing the good alignment and arch form. The extraoral photographs (f, g, h) disclose a nice face, harmonious orofacial musculature, and pleasant smile. FIGURE 9. Radiographs periapical (a, b, c) and panoramic (d) at the end of the treatment, exhibiting normal aspect in the periodontal structures and surrounding tissues. A small degree of root resorption on the canines and central incisors, and small height loss of alveolar crest, but without clinical significance. Observe that the spaces of the missing teeth are closed. panoramic and periapical radiographs (Figure 9). Final cephalometrics measurements (Figure 10; Tables 1 and 2) showed the same facial balance as that at the beginning of treatment, demonstrating that space closure produced no negative influence on the middle third of the face. The patient s records taken seven years and seven months after treatment show the excellent stability of the occlusion and facial balance. No spaces are present in the upper arch, the posterior occlusion presents an acceptable intercuspation (Figures 11 and 12), and there is correct root angulation of the teeth (Figure 13). Figure 5 shows the risk in reversing transposed teeth. The alveolar bone width is always too narrow to allow both teeth to move inside it. The first premolar has to be moved palatally to avoid any damage to the labial cortical bone or root interference or resorption (Figure 6f). After the canine was moved mesially, the fist premolars were brought back to the alveolar bone, and leveling and alignment were com-

272 AJALMAR MAIA, GALVÃO MAIA FIGURE 10. Final cephalometric tracing and measurements. pleted. During the leveling phase, Class III elastics or a face mask were used to bring the upper teeth forward to a Class II relationship (Figure 6g,h). Ideal 0.018 0.025 inch arches were placed with individual lingual root torque on the upper canines and with labial root torque on the first premolars (Figure 7). The fixed appliance was removed after four years and nine months of treatment (Figure 8), and the patient received an upper removable and a lower canine-to-canine fixed retainer. DISCUSSION When teeth are transposed, their natural sequence in the arch is changed, leading to functional and esthetic problems, especially if the transposed teeth are grossly out of arch alignment. If transposition is associated with a malocclusion, the case becomes even more difficult to treat and the prognosis worsens. It is surprising that publications on this matter are sporadic and limited to case reports with no treatment. 1,3 5,12 The case presented here is difficult to treat because of bilateral teeth transposition and lateral incisor agenesis. The common procedure has been to maintain the teeth in their original positions, with the first premolars coming in contact with the lateral incisor. 6,7,29 In a similar case, Laptook and Silling 18 reversed only the right side and kept both upper lateral incisor spaces for implants or prostheses. During treatment planning, one has to define if it is possible to correct the tooth order in the arch and if there is an advantage in closing the congenitally missing lateral incisor space. Aspects that have to be considered include difficulty, time, risks, esthetics, function, stability, biological sacrifice or damage, mechanic device, professional preference, and experience. I have treated many cases of transposed teeth of different types and five cases were treated orthodontically without correcting the tooth order. These showed a poor result as compared with cases treated by reversing the tooth order. Based on these experiences, my personal preference is always to reverse the tooth order when possible. The difficulties are great, but with good control of force direction, you will be successful. Some literature refers to the reversal of tooth transposition as heroic orthodontics. Surely, it is not a treatment for a novice without good orientation. The torque control and movement of the transposed teeth while preserving the vestibular cortical bone plate and the gingival level are great orthodontic difficulties. Obviously, this approach needs more treatment time, and

TRANSPOSITION OF TEETH 273 FIGURE 11. Intraoral photographs (a, b, c) of patient seven years and seven months after treatment showing transposition correction and intercuspation stability. The upper canines moved to the missing teeth spaces are stable. (d, e) Upper and lower arch occlusal view showing the arch shape and the spaces closed, and the result is agreeable. The extraoral photographs exhibit a nice face, harmonious orofacial musculature (f, g), and pleasant smile (h). treatment time is often the key in judging treatment results. However, the stability, esthetics, and function are benefited. When one has an upper canine between the upper premolars, the functional movements and stability are worse then when a canine is placed in the lateral site. Sometimes one has to make a premolar crown on the canine and give it a palatal cusp to stabilize the occlusion. In this particular case, the treatment time was four years and nine months, but the patient missed five strategic visits and failed in elastic and facial mask use, which delayed the treatment and resulted in not totally closing all the spaces. The real treatment time took four years and four months, but the result can be considered very good, despite the risks involved and the patient cooperation problems. Negligence in oral hygiene favored decalcifications and cavities that esthetically compromised the result. This probably made the maxillary canines look aged and made necessary some posttreatment fillings, a root canal, and a crown on the left lower first molar (36). This outcome is not directly related to the transposition treatment, but to patient cooperation. Maxillary canine first premolar transposition is often associated with upper lateral agenesis. The treatment solution options for this situation are implant, prosthesis, or ortho-

274 AJALMAR MAIA, GALVÃO MAIA FIGURE 12. Cephalometric radiography (a) tracing and measurements (b) seven years and seven months after treatment. dontic space closure. The decision is based on advantages and disadvantages. In this case, the facial profile, the facial mild third convexity, the smile height, the cephalometric jaw relationship associated with the patient, and parent s opinion favored the decision to close the lateral agenesis space. The option whether to close the spaces or not in the cases of maxillary lateral agenesis is always a matter of great controversy mainly because the treatment becomes longer and more difficult, compared with an implant placement. Some authors prefer an implant or prosthetic solution because they believe some aspects of the space closure to be disadvantageous. When the option is to close the space of the upper lateral agenesis, one relies on some important variables such as the different color, shape, and size of the canine in the lateral site, the different root prominence, and the different height of the gingival scallops. Would not this be the price to pay? The root resorption level and the gingival contour are a little higher but are at acceptable levels without significant biological damage. The patient s opinion was reported as happy with her smile and appearance and happy because she is not using a prosthetic device. Considering the patient s esthetics and age, it is difficult to understand the treatment approach that requires a 14- year-old to use a removable prosthesis until she is 18 and can receive a fixed prosthesis or implant. This is the only case report treated by reversing the bilateral transposition and orthodontically closing the upper lateral incisor spaces. This approach is a realistic treatment plan. It is easy to tell the patient that he will need to use prosthesis or implant when he is older and can pay for it. On the other hand, we have to consider that the use of a removable retainer with anterior teeth on it during adolescence is not a very easy situation for the patient. We choose this orthodontic approach because once it was decided to close the congenitally missing upper lateral incisor spaces, it was inappropriate to position the upper first premolars in contact with the central incisors. In 20 years of treating various types of teeth transpositions in both jaws, I am convinced that orthodontically reversing transposed teeth is a viable possibility in the majority of cases. All treatment risks should be considered, and special attention should be given to esthetics, occlusion, canine apex position, root resorption, periodontal structures, and the patient s age. Although in some situations function and esthetics demand correction, the key to success is to develop well-controlled orthodontic procedures to decrease the potential risks and lessen the possibilities for unsuccessful treatment. The treatment time in this case was 57 months, but the results reinforced by the long-term records make this treatment very good despite the risks involved. CONCLUSIONS Many case reports of uncorrected dental transpositions have been published, but most of them report orthodontic

TRANSPOSITION OF TEETH 275 FIGURE 13. Panoramic radiography seven years and seven months after treatment. treatment restricted to alignment and leveling of the transposed teeth in their original reversed positions. This case report is a new approach in orthodontics for the treatment of tooth transposition. We believe that it is possible to orthodontically treat this challenging anomaly in an efficient way. 8,10,11,30 32 Although this treatment approach can and should be done, one must always consider the physiological limits and avoid procedures which could damage periodontal structures or cause root resorption. ACKNOWLEDGMENT We thank Dr. Dione Vale of the UFPE (Universidade Federal de Pernambuco) for her help in the preparation of the English version of the manuscript. REFERENCES 1. Peck L, Peck S, Attia Y. Maxillary canine first premolar transposition, associated to dental anomalies and genetic basis. Angle Orthod. 1993;63:99 109. 2. Josh MR, Bhatt NA. Canine transposition. Oral Surg. 1971;31: 49 54. 3. Chattopadhyay A, Sriniyas K. Transposition of teeth and genetic etiology. Angle Orthod. 1966;36:147 152. 4. Peck S, Peck L. Classification of maxillary tooth transposition. Am J Orthod Dentofacial Orthop. 1995;107:505 517. 5. Mader C, Konzelman JL. Transposition of teeth. J Am Dent Assoc. 1979;98:412 413. 6. Nestel E, Walsh JS. Substitution of a transposed premolar for a congenitally absent lateral incisor. Am J Orthod Dentofacial Orthop. 1988;93:395 399. 7. Parker WS. Transposed premolars, canines, and lateral incisors. Am J Orthod Dentofacial Orthop. 1990;97:431 448. 8. Maia FA. Transposições dentárias um dilema no tratamento ortodôntico. Rev Dental Press Ortod Ortop Facial. 1999;4:21 35. 9. Shapira Y, Kuftinec MM. Maxillary canine Lateral incisor transposition orthodontic management. Am J Orthod Dentofacial Orthop. 1989;95:439 444. 10. Maia FA. Transposition of maxillary canine and lateral incisor orthodontic reversion. Angle Orthod. 2000;70:339 348. 11. Maia FA. Transmigração de canino mandibular. Ortodontia. 2000; 33:55 60. 12. Jackson M. Upper canine in position of upper central incisor. Br Dent J. 1951;90:243. 13. Göyenç Y, Karaman I, Gökalp A. Unusual ectopic eruption of maxillary canines. J Clin Orthod. 1995;29:580 582. 14. Wasserstein A, Tzur B, Brezniak N. Incomplete canine transposition and maxillary central incisor impaction a case report. Am J Orthod Dentofacial Orthop. 1997;111:635 639. 15. Peck S, Peck L, Kataja M. Mandibular lateral incisor canine transposition, concomitant dental anomalies and genetic control. Angle Orthod. 1998;68:455 466. 16. Payne GS. Bilateral transposition of maxillary canines and premolars: report of two cases. Am J Orthod. 1969;56:45 52. 17. Allen WA. Bilateral transposition of teeth in two brothers. Br Dent J. 1967;123:439 440. 18. Laptook T, Silling G. Canine transposition approaches to treatment. J Am Dent Assoc. 1983;107:746 748. 19. Lukacs JR. Canine transposition in prehistoric Pakistan: bronze age and iron age case report. Angle Orthod. 1998;68:475 480. 20. Nelson GC. Maxillary canine third premolar transposition in a prehistoric population from Santa Cruz Island, California. Am J Phys Anthropol. 1992;88:134 144. 21. Dayal PK, Shodhan KH, Dave CJ. Transposition of canine with traumatic etiology. J Indian Dent Assoc. 1983;55:283 285. 22. Platzer KM. Mandibular incisor canine transposition. Am Dent Assoc. 1968;76:778 784. 23. Stafne EC. Oral Roentgenography Diagnosis. 3rd ed. Philadelphia, Pa: WB Saunders; 1969:27. 24. Peck S. On the phenomenon of intraosseous migration of nonerupting teeth. Am J Orthod Dentofacial Orthop. 1998;113:515 517. 25. Feichtinger CH, Rossiwall B, Wuanderrer H. Canine transposition as autosomal recessive trait in an imberg kindered. J Dent Res. 1997;56:1449 1452. 26. Van der Linden FPGM. Ortodontia Desenvolvimento da dentição. Sao Paulo, Brazil: Quintessence; 1986:47 55.

276 AJALMAR MAIA, GALVÃO MAIA 27. Farrar JN. Irregularities of the Teeth and Their Correction. London, UK: International News Company; 1888:962 967. 28. Shapira Y, Kuftinel MM. Tooth transposition review of literature and treatment considerations. Angle Orthod. 1989;59:271 276. 29. Ranta R. Tooth germ transposition: report of cases. J Den Child. 1989;56:366 370. 30. Maia FA. Transposição de canino com o incisivo lateral inferior uma visão ortodôntica. Rev Dental Press Ortod Ortop Facial. 2000;5:79 88. 31. Maia FA, Cardoso RSC. Transposição de canino superior e tracionamento para o lugar do incisivo central caso clínico. Rev Dental Clín Ortod Dental Press. 2003;2:45 55. 32. Maia FA. As transposições dentárias uma abordagem ortodôntica. Uma nova visão em ortodontia e ortopedia facial, cap.23-431-437. Sao Paulo, Brazil: Santos Livraria e Editoral.