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Trauma as a possible etiologic factor in maxillary canine impaction
Trauma as a possible etiologic factor in maxillary canine impaction liana Brin, ~ Y v o n n e S o l o m o n , b and Yerucham Zilberman c
Jerusalem, Israel A chain of events in the development of the dentition following trauma is described. Shortening of the root of the lateral incisor or displacement of the tooth bud, both as a sequel to trauma, may affect the path of eruption of the adjacent canine after dental injury. Special attention should be paid to the further development and eruption of the directly and indirectly affected teeth. (AM J ORTHOO DENTOFACORTHOP 1993;104:132-7.)
M a x i l l a r y canine impaction is a well-documented phenomenon, particularly in the recent orthodontic literature. The mechanism causing the deviated path of eruption appears to be related to the lack of guidance normally rendered by the root of the lateral incisor. ~4 Traumatic injurY.to the region has not been mentioned in the literature'as a direct etiologic factor of impaction, although it is considered so in the cases of transposition of teeth2 The purpose of this communication is to present two cases of maxillary canine impaction that developed after trauma to the incisor region, suggesting a possible connection between the two events.
Facultyof DentalMedicine,Itebrew University-lladassahSchoolof Dental Medicine,foundedby the AlphaOmegaFraternity. "SeniorLecturer,Departmentof Orthodontics. t'GraduateStudent,Departmentof Endodontics. ~ClinicalAssociateProfessor,Departmentof Orthodontics. Copyright9 1993by the AmericanAssociationof Orthodontist~. 0589-5406/93/SI.00 + 0.10 8/1/35277
CASE HISTORY 1
A 9-ycar-old girl was referred to the Department of Orthodontics of the Hebrew University-Hadassah School of Dental Medicine 27 months after a severe traumatic injury to her maxillary incisors. The initial postinjury examination was made 2 weeks after the accident in the Department of Pedodontics. It revealed extrusion of both maxillary right incisors, which showed second degree mobility. The left central maxillary incisor was subluxated and exhibited some mobility (first degree), while the fight deciduous canine was lost at the time of the trauma. Roentgenographie examination at that time indicated more than half of the incisor root developed, an open apex, and some periodontal rarification in the periapical region of the right incisors (Fig. 1). The permanent canine buds appeared to be developing normally and in an apparently good position on both sides. The treatment rendered at that time was pulpectomy of the right central and lateral incisors, Calxyl root filling (OCO Priiparate GmbH, D-6716, Dirmstein, Germany), a composite splint of all the maxillary incisors, oral hygiene, and instructions for a soft diet. On the next visit the patient had breakage of the splint, which was subsequently removed. The Calxyl
Fig. 1. Case 1. Periapical roentgenograms of maxillary anterior teeth of a 71/z-year-old girl 2 weeks after the accident. 132
American Journal of Orthodontics and Dtntofacial Orthopedics Volume 104, No. 2
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133
Fig. 2. Periapical roentgenograms of right and left maxillary canines 27 months after the accident.
h Fig. 3. Intraoral views of patient at age of 91/zyears.
root filling was repeated several times, and the patient was referred to the Department of Endodontics for the definitive treatment. The final root canal therapy and composite fillings were performed 1 year after ihe injury. During the postoperative follow-up, the right maxillary canine seemed to become mesially misplaced, and a cystic lesion was noticed in
the region (Fig. 2). The patient was then referred to the Department of Orthodontics. The patient, now 10 years old, was described as a skeletal and dentoalveolar Class I, brachycephalie type, in the late mixed dentition stage (Fig. 3). Oral hygiene was poor, and the upper maxillary incisors were slightly mobile (first
134
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American Journal of Orthodontics and Dentofacial Orthol,,,dics August 1993
the exfoliation or extraction of the first deciduous molar, the area would be restored prosthetically. At surgical exposure, the buccal plate of bone of the lateral incisor was found to be missing, and the tooth was extracted. Traction of the impacted canine to replace the lateral incisor was then implemented (Fig. 4).
CASE HISTORY 2
Fig. 4. Periapical roentgenogram of right maxillary canine a shortly after surgical intervention.
degree). The uncrupted canines could be palpated palatally on the right side and buccally on the left. The upper first right premolar had erupted into the canine position, whereas the first right deciduous molar was retained and mildly infraoceluded. Rocntgenographic examination at this stage revealed a mesiopalatally positioned right canine bud and a cystic lesion whose origin was either from the impacted canine or from the adjacent root-treated lateral incisor (Fig. 2). Root resorption of this incisor was also evident. The orthodontic treatment plan included: oral hygiene instruction, splinting of the incisors by means of an orthodontic rectangular wire firmly tied into bonded brackets, surgical exploration of the region of the lateral incisor, exposure of the impacted canine, and bonding of a bracket to it. Two possible alternative treatment plans were considered as follows: I. If the periodontal support of the lateral incisor was acceptable, the first deciduous molar could be extracted, the first premolar distalizcd and the impacted canine brought to place. 2. If the periodontal support of the lateral incisor was unsatisfactory, this tooth would be extracted, and the impacted canine brought into the position of the lateral incisor. The first premolar would remain in the position of the canine, while the first deciduous molar would be left in situ as long as possible. Later, on
A 71A-year-old girl was referred to the Department of Orthodontics of the ttebrew Univcrsity-Hadassah School of Dental Medicine by her pedodontist with a complaint of an unerupted maxillary central incisor. The erupcd left central and right lateral incisors were mesially tipped, encroaching on the space for the right central incisor. Roentgenographic examination revealed a horizontally impacted right central incisor with the apex in close proximity to the anterior nasal spine and the crown pointing palatally (Fig. 5, A and B). However, the final position of the maxillary permanent canines could not be predicted from these radiographs alone." Severe mesial tipping of the adjacent incisors was confirmed roentgenographically. The parents reported a traumatic injury to the anterior maxillary region at an earlier age. As her dental development was still in its early stages, albeit well related to her chronologic age, treatment was postponed, and the patient was kept under observation. Fifteen months later, when incisor root development was more advanced, orthodontic records were collected, and the treatment plan for phase I was established. This involved aligning and paralleling the teeth in the dental arch, space opening for the impacted incisor, surgical exposure, and traction. Reevaluation was planned before embarking on phase 11, since the prognosis of the impacted cental incisor was not clear at this stage. A high-pull headgear and a 2 • 4 edgewise appliance Were placed. Horizontal tubes were soldered to the palatal aspect of the first molar bands to enable vertical positioning of the impacted central incisor according to the method developed for the treatment of impacted canines.' After alignment of the anterior segment and appropriate space opening, the right central incisor was surgically exposed, and a bracket bonded to its labial surface. Gentle traction of the impacted tooth was commenced, and a year later, the tooth erupted into the oral cavity. Roentgenographic follow-up during that period indicated loss of eruption.guidance to the right canine, although the position of the lateral incisor on the same side had improved during the first phase of treatment (Fig. 6, A). The left maxillary canine was in a better position, however, exhibiting an enlarged dental sac (Fig. 6, B). The two deciduous maxillary canines were extracted at the age of 10 years 4 months. The position of the left canine bud seemed to improve spontaneously, which was not the case regarding its right antimer (Fig. 7, A and B).
DISCUSSION Dental trauma has been presented previously as a factor affecting the further development o f the succes-
American Journal of Orthodontics and Dentofizcial Orthopedics Volume 104, No. 2
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135
B Fig. 5. Case 2. A, Panoramic view of a 71/2-year-oldgirl. B, Tangential view of the same patient. Note the close proximity of the root of the right central incisor to the anterior nasal spine and the palatally pointing crown.
sors tO injured teeth. 9 Incisor malalignment, '~ as well as tooth transposition, ~ were reported. Fractures of the jaws were also found to be associated with canine impaction." The effect of trauma to the incisors (without jaw fractures) on canine impaction may, however, be indirect as suggested in the previously mentioned case reports. In the classical description of the maxillary permanent canine eruption path, ~2 the root of the lateral permanent incisor plays a cardinal role. Howcver, when
the erupting canine fails to obtain a normal position because of unsatisfactory guidance of the lateral incisor -root, ~'2 excessive space in the maxillary bone, ~3 or for 9an), other reason, it is often impacted. In the first case presented here, the root of the right lateral incisor was shortened, probably as the result of thetraumatic ifijury, followed by root canal therapy, and arrest of root formation (Fig. 2). This, in turn, could affect the path of eruption of the adjacent canine bud. This hypothesis is further supported by the fact
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Fig. 6. A, Periapical roentgenogram demonstrating position of right central incisor I year after surgical exposure. Note the location of the right canine bud. B, Periapical roentgenogram of the left maxillary canine bud. Note the enlarged dental sac.
Fig. 7. A, Periapical roentgenogram of impacted right maxillary canine. B, Periapical roentgenogram of the left maxillary canine. Note the improved path of eruption.
that, initially, the two canine buds exhibited a similar position in relation-to the incisors (Fig. 1). However, after the injury to the right maxillary dentition, the right canine seemed to deviate from the normal eruption path, while the left canine continued to erupt into a normal position (Fig. 2). In the second case presented, the malalignment of the anterior segment after the traumatic injury may have been responsible for loss of guidance to the erupting canine. The malposed right lateral incisor seems to have lost the desirable relationship with the adjacent canine
bud at a critical stage of dental development. A similar phenomenon may explain the mesial eruption of the right first premolar in case 1. This appears to have occurred as the result of the mesial migration of the canine, which, in turn, provided space for the migration of the premolar that erupted mesial to its deciduous predecessor. CONCLUSIONS
1. Trauma to the anterior area ot me aentltlOn may lead to abnormality in the path of eruption of
American Journal of Orthodontics and Dentofacial Orthopedics Volume 104, No. 2
adjacent canines, which may result in their impaction or ectopic eruption. 2. Special attention should be paid in these cases to the development of the apparently unharmed neighboring teeth and not only to the development of the directly injured teeth. We thank Prof. A. Becker for critiquing the final manuscript. REFERENCES 1. Becket A, Zilberman Y, Tsur B. Root length of lateral incisors adjacent to palatally-displaced maxillary cuspids. Angle Orthod
1984;4:218-25. 2. Oliver RG, Mannion JE, Robinson JM. Morphology of the maxillary lateral incisor in cases of unilateral impaction of the maxillary canine. Br J Orthod 1989;19:9-16. 3. Becker A, Smith P, Behar R. The incidence of anomalous lateral incisors in relation to palatally-displaced cuspids. Angle Ortbod 1981;51:24-9. 4. Brin I, Becker A, Shalhav M. Position of the maxillary permanent canine in relation to anomalous or missing lateral incisor: a population study. Eur J Orthod 1986;8:12-6. 5. Ben-Bassat Y, Brin I, Zilberman Y. Effect of trauma to the primary incisors: multidisciplinary treatment approach. J Dent Child 1989;50:112-6.
Brin, S o l o m o n , a n d Z i l b e r m a n
137
6. Ericson S, Kurol J. Radiographic assessment of maxillary canine eruption in children with clinical signs of eruption disturbance. Eur J Orthod 1986;8:133-40. 7. Becker A, Zilberman Y. The palatally impacted canine: a new approach to its treatment. AM J ORTnOD 1978;74:422-9. "8. Andreasen JO. Traumatic injuries of the teeth. Copenhagen: Munksgaard, 1981:304-8. 9. Ben-Bassat Y, Brin I, Fuks A, Zilberman Y. Trauma to the primary incisors and its effect on the permanent successors in different developmental stages. Pediatr Dent 1985;7:37-40. 10. Brin I, Ben-Bassat Y, Zilberman Y, Fuks A. Trauma to the primary incisors and its effect on the alignment of their permanent successors. Community Dent Oral Epidemiol 1988;16:104-8. 11. Lenstrup K. On injury by fractures of the jaws to teeth in course of formation. Acta Odont Scand 1955;13:181-202. 12. Broadbent BH. The face of the nomlal child. Angle Orthod 1937;7:183-208. 13. Jacoby H. The etiology of maxillary canine impactions. A~.I J OR'roOD 1983;84:125-32.
Reprint requests to: Dr. I. Brin Department of Orthodontics Hebrew University-Hadassah School of Dental Medicine POB 1172 Jerusalem, Israel
Jerusalem, Israel A chain of events in the development of the dentition following trauma is described. Shortening of the root of the lateral incisor or displacement of the tooth bud, both as a sequel to trauma, may affect the path of eruption of the adjacent canine after dental injury. Special attention should be paid to the further development and eruption of the directly and indirectly affected teeth. (AM J ORTHOO DENTOFACORTHOP 1993;104:132-7.)
M a x i l l a r y canine impaction is a well-documented phenomenon, particularly in the recent orthodontic literature. The mechanism causing the deviated path of eruption appears to be related to the lack of guidance normally rendered by the root of the lateral incisor. ~4 Traumatic injurY.to the region has not been mentioned in the literature'as a direct etiologic factor of impaction, although it is considered so in the cases of transposition of teeth2 The purpose of this communication is to present two cases of maxillary canine impaction that developed after trauma to the incisor region, suggesting a possible connection between the two events.
Facultyof DentalMedicine,Itebrew University-lladassahSchoolof Dental Medicine,foundedby the AlphaOmegaFraternity. "SeniorLecturer,Departmentof Orthodontics. t'GraduateStudent,Departmentof Endodontics. ~ClinicalAssociateProfessor,Departmentof Orthodontics. Copyright9 1993by the AmericanAssociationof Orthodontist~. 0589-5406/93/SI.00 + 0.10 8/1/35277
CASE HISTORY 1
A 9-ycar-old girl was referred to the Department of Orthodontics of the Hebrew University-Hadassah School of Dental Medicine 27 months after a severe traumatic injury to her maxillary incisors. The initial postinjury examination was made 2 weeks after the accident in the Department of Pedodontics. It revealed extrusion of both maxillary right incisors, which showed second degree mobility. The left central maxillary incisor was subluxated and exhibited some mobility (first degree), while the fight deciduous canine was lost at the time of the trauma. Roentgenographie examination at that time indicated more than half of the incisor root developed, an open apex, and some periodontal rarification in the periapical region of the right incisors (Fig. 1). The permanent canine buds appeared to be developing normally and in an apparently good position on both sides. The treatment rendered at that time was pulpectomy of the right central and lateral incisors, Calxyl root filling (OCO Priiparate GmbH, D-6716, Dirmstein, Germany), a composite splint of all the maxillary incisors, oral hygiene, and instructions for a soft diet. On the next visit the patient had breakage of the splint, which was subsequently removed. The Calxyl
Fig. 1. Case 1. Periapical roentgenograms of maxillary anterior teeth of a 71/z-year-old girl 2 weeks after the accident. 132
American Journal of Orthodontics and Dtntofacial Orthopedics Volume 104, No. 2
Brin, Solomon, and Zilberman
133
Fig. 2. Periapical roentgenograms of right and left maxillary canines 27 months after the accident.
h Fig. 3. Intraoral views of patient at age of 91/zyears.
root filling was repeated several times, and the patient was referred to the Department of Endodontics for the definitive treatment. The final root canal therapy and composite fillings were performed 1 year after ihe injury. During the postoperative follow-up, the right maxillary canine seemed to become mesially misplaced, and a cystic lesion was noticed in
the region (Fig. 2). The patient was then referred to the Department of Orthodontics. The patient, now 10 years old, was described as a skeletal and dentoalveolar Class I, brachycephalie type, in the late mixed dentition stage (Fig. 3). Oral hygiene was poor, and the upper maxillary incisors were slightly mobile (first
134
Brhz, Solomon, and Zilberman
American Journal of Orthodontics and Dentofacial Orthol,,,dics August 1993
the exfoliation or extraction of the first deciduous molar, the area would be restored prosthetically. At surgical exposure, the buccal plate of bone of the lateral incisor was found to be missing, and the tooth was extracted. Traction of the impacted canine to replace the lateral incisor was then implemented (Fig. 4).
CASE HISTORY 2
Fig. 4. Periapical roentgenogram of right maxillary canine a shortly after surgical intervention.
degree). The uncrupted canines could be palpated palatally on the right side and buccally on the left. The upper first right premolar had erupted into the canine position, whereas the first right deciduous molar was retained and mildly infraoceluded. Rocntgenographic examination at this stage revealed a mesiopalatally positioned right canine bud and a cystic lesion whose origin was either from the impacted canine or from the adjacent root-treated lateral incisor (Fig. 2). Root resorption of this incisor was also evident. The orthodontic treatment plan included: oral hygiene instruction, splinting of the incisors by means of an orthodontic rectangular wire firmly tied into bonded brackets, surgical exploration of the region of the lateral incisor, exposure of the impacted canine, and bonding of a bracket to it. Two possible alternative treatment plans were considered as follows: I. If the periodontal support of the lateral incisor was acceptable, the first deciduous molar could be extracted, the first premolar distalizcd and the impacted canine brought to place. 2. If the periodontal support of the lateral incisor was unsatisfactory, this tooth would be extracted, and the impacted canine brought into the position of the lateral incisor. The first premolar would remain in the position of the canine, while the first deciduous molar would be left in situ as long as possible. Later, on
A 71A-year-old girl was referred to the Department of Orthodontics of the ttebrew Univcrsity-Hadassah School of Dental Medicine by her pedodontist with a complaint of an unerupted maxillary central incisor. The erupcd left central and right lateral incisors were mesially tipped, encroaching on the space for the right central incisor. Roentgenographic examination revealed a horizontally impacted right central incisor with the apex in close proximity to the anterior nasal spine and the crown pointing palatally (Fig. 5, A and B). However, the final position of the maxillary permanent canines could not be predicted from these radiographs alone." Severe mesial tipping of the adjacent incisors was confirmed roentgenographically. The parents reported a traumatic injury to the anterior maxillary region at an earlier age. As her dental development was still in its early stages, albeit well related to her chronologic age, treatment was postponed, and the patient was kept under observation. Fifteen months later, when incisor root development was more advanced, orthodontic records were collected, and the treatment plan for phase I was established. This involved aligning and paralleling the teeth in the dental arch, space opening for the impacted incisor, surgical exposure, and traction. Reevaluation was planned before embarking on phase 11, since the prognosis of the impacted cental incisor was not clear at this stage. A high-pull headgear and a 2 • 4 edgewise appliance Were placed. Horizontal tubes were soldered to the palatal aspect of the first molar bands to enable vertical positioning of the impacted central incisor according to the method developed for the treatment of impacted canines.' After alignment of the anterior segment and appropriate space opening, the right central incisor was surgically exposed, and a bracket bonded to its labial surface. Gentle traction of the impacted tooth was commenced, and a year later, the tooth erupted into the oral cavity. Roentgenographic follow-up during that period indicated loss of eruption.guidance to the right canine, although the position of the lateral incisor on the same side had improved during the first phase of treatment (Fig. 6, A). The left maxillary canine was in a better position, however, exhibiting an enlarged dental sac (Fig. 6, B). The two deciduous maxillary canines were extracted at the age of 10 years 4 months. The position of the left canine bud seemed to improve spontaneously, which was not the case regarding its right antimer (Fig. 7, A and B).
DISCUSSION Dental trauma has been presented previously as a factor affecting the further development o f the succes-
American Journal of Orthodontics and Dentofizcial Orthopedics Volume 104, No. 2
Brin, Solomon, and Zilberman
135
B Fig. 5. Case 2. A, Panoramic view of a 71/2-year-oldgirl. B, Tangential view of the same patient. Note the close proximity of the root of the right central incisor to the anterior nasal spine and the palatally pointing crown.
sors tO injured teeth. 9 Incisor malalignment, '~ as well as tooth transposition, ~ were reported. Fractures of the jaws were also found to be associated with canine impaction." The effect of trauma to the incisors (without jaw fractures) on canine impaction may, however, be indirect as suggested in the previously mentioned case reports. In the classical description of the maxillary permanent canine eruption path, ~2 the root of the lateral permanent incisor plays a cardinal role. Howcver, when
the erupting canine fails to obtain a normal position because of unsatisfactory guidance of the lateral incisor -root, ~'2 excessive space in the maxillary bone, ~3 or for 9an), other reason, it is often impacted. In the first case presented here, the root of the right lateral incisor was shortened, probably as the result of thetraumatic ifijury, followed by root canal therapy, and arrest of root formation (Fig. 2). This, in turn, could affect the path of eruption of the adjacent canine bud. This hypothesis is further supported by the fact
136
Brin, Solomon, and Zilberman
American Journal of Orthodontics and Dentofacia/ Orthopedics August 1993
Fig. 6. A, Periapical roentgenogram demonstrating position of right central incisor I year after surgical exposure. Note the location of the right canine bud. B, Periapical roentgenogram of the left maxillary canine bud. Note the enlarged dental sac.
Fig. 7. A, Periapical roentgenogram of impacted right maxillary canine. B, Periapical roentgenogram of the left maxillary canine. Note the improved path of eruption.
that, initially, the two canine buds exhibited a similar position in relation-to the incisors (Fig. 1). However, after the injury to the right maxillary dentition, the right canine seemed to deviate from the normal eruption path, while the left canine continued to erupt into a normal position (Fig. 2). In the second case presented, the malalignment of the anterior segment after the traumatic injury may have been responsible for loss of guidance to the erupting canine. The malposed right lateral incisor seems to have lost the desirable relationship with the adjacent canine
bud at a critical stage of dental development. A similar phenomenon may explain the mesial eruption of the right first premolar in case 1. This appears to have occurred as the result of the mesial migration of the canine, which, in turn, provided space for the migration of the premolar that erupted mesial to its deciduous predecessor. CONCLUSIONS
1. Trauma to the anterior area ot me aentltlOn may lead to abnormality in the path of eruption of
American Journal of Orthodontics and Dentofacial Orthopedics Volume 104, No. 2
adjacent canines, which may result in their impaction or ectopic eruption. 2. Special attention should be paid in these cases to the development of the apparently unharmed neighboring teeth and not only to the development of the directly injured teeth. We thank Prof. A. Becker for critiquing the final manuscript. REFERENCES 1. Becket A, Zilberman Y, Tsur B. Root length of lateral incisors adjacent to palatally-displaced maxillary cuspids. Angle Orthod
1984;4:218-25. 2. Oliver RG, Mannion JE, Robinson JM. Morphology of the maxillary lateral incisor in cases of unilateral impaction of the maxillary canine. Br J Orthod 1989;19:9-16. 3. Becker A, Smith P, Behar R. The incidence of anomalous lateral incisors in relation to palatally-displaced cuspids. Angle Ortbod 1981;51:24-9. 4. Brin I, Becker A, Shalhav M. Position of the maxillary permanent canine in relation to anomalous or missing lateral incisor: a population study. Eur J Orthod 1986;8:12-6. 5. Ben-Bassat Y, Brin I, Zilberman Y. Effect of trauma to the primary incisors: multidisciplinary treatment approach. J Dent Child 1989;50:112-6.
Brin, S o l o m o n , a n d Z i l b e r m a n
137
6. Ericson S, Kurol J. Radiographic assessment of maxillary canine eruption in children with clinical signs of eruption disturbance. Eur J Orthod 1986;8:133-40. 7. Becker A, Zilberman Y. The palatally impacted canine: a new approach to its treatment. AM J ORTnOD 1978;74:422-9. "8. Andreasen JO. Traumatic injuries of the teeth. Copenhagen: Munksgaard, 1981:304-8. 9. Ben-Bassat Y, Brin I, Fuks A, Zilberman Y. Trauma to the primary incisors and its effect on the permanent successors in different developmental stages. Pediatr Dent 1985;7:37-40. 10. Brin I, Ben-Bassat Y, Zilberman Y, Fuks A. Trauma to the primary incisors and its effect on the alignment of their permanent successors. Community Dent Oral Epidemiol 1988;16:104-8. 11. Lenstrup K. On injury by fractures of the jaws to teeth in course of formation. Acta Odont Scand 1955;13:181-202. 12. Broadbent BH. The face of the nomlal child. Angle Orthod 1937;7:183-208. 13. Jacoby H. The etiology of maxillary canine impactions. A~.I J OR'roOD 1983;84:125-32.
Reprint requests to: Dr. I. Brin Department of Orthodontics Hebrew University-Hadassah School of Dental Medicine POB 1172 Jerusalem, Israel