Orthodontic Treatment of an Impacted Dilacerated Maxillary Central Incisor Combined with Surgical Exposure and Apicoectomy

Transcription

1 Case Report Orthodontic Treatment of an Impacted Dilacerated Maxillary Central Incisor Combined with Surgical Exposure and Apicoectomy Setsuko Uematsu, DDS, PhD a ; Takashi Uematsu, DDS, PhD b ; Kiyofumi Furusawa DDS, PhD c ; Toshio Deguchi, DDS, PhD d ; Saburo Kurihara, DDS, PhD e Abstract: The impacted incisor was moved into its proper position with surgical exposure and orthodontic traction. Although apicoectomy was performed during the orthodontic treatment, the incisor showed good stability after the long retention period. (Angle Orthod 2004;74: ) Key Words: Impacted teeth; Dilacerated root; Apicoectomy INTRODUCTION Although impaction of a permanent tooth is rarely diagnosed during the mixed dentition period, an impacted central incisor is usually diagnosed accurately when there is delay in the eruption of the tooth. Many patients with impacted maxillary central incisors are referred to orthodontists by general practitioners or pediatric dentists because parents are concerned about the impaction of an incisor in the early mixed dentition, even though its occurrence is less frequent. 1 3 Tooth impaction may result from a number of local causes. In an extensive review, Bishara 4 lists the etiologic factors of tooth impaction. Although trauma was not included as a factor, he refers to the abnormal position of tooth bud, which might be caused by trauma. Careful planning is required when moving an impacted tooth by orthodontic treatment. Impacted teeth can be properly positioned with orthodontic traction. 2,3,5 7 However, orthodontists often hesitate to align an impacted incisor with severe dilaceration because there are chances of failure due to ankylosis, loss of attachment, external root resorption, and root exposure after orthodontic retraction. 2 Patients usually want to retain and align the impacted teeth into proper position even after orthodontists suggest several treatment plans. This article presents a case with a horizontally impacted and severely dilacerated maxillary right incisor that was aligned into proper position after orthodontic treatment combined with surgical exposure and apicoectomy, after which it showed good long-term periodontal stability. Case history A 11-year-old Japanese girl presented with an impacted right maxillary central incisor. The chief complaint was noneruption of the incisor (Figure 1). The child was in good health and had no history of medical or dental trauma. Diagnosis and treatment planning The patient had a skeletal Class I malocclusion and a balanced facial pattern. Intraoral examination revealed an a Assistant Professor, Department of Orthodontics, School of Dentistry, Matsumoto Dental University, Nagano, Japan. b Associate Professor, Department of Oral & Maxillofacial Surgery, School of Dentistry, Matsumoto Dental University, Nagano, Japan. c Professor, Department of Oral & Maxillofacial Surgery, School of Dentistry, Matsumoto Dental University, Nagano, Japan. d Professor, Institute for Oral Science, Matsumoto Dental University, Nagano, Japan. e Professor, Department of Orthodontics, School of Dentistry, Matsumoto Dental University, Nagano, Japan. Corresponding author: Setsuko Uematsu, DDS, PhD, Department of Orthodontics, School of Dentistry, Matsumoto Dental University, 1780 Hirooka Gohbara, Shojiri, Nagano , Japan ( setsuko@po.mdu.ac.jp). Accepted: March Submitted: January by The EH Angle Education and Research Foundation, Inc. FIGURE 1. Intraoral photograph of pretreatment condition (11 years eight months old). 132

2 IMPACTED MAXILLARY INCISOR WITH DILACERATED ROOT 133 FIGURE 3. (a) Adequate space for alignment of the impacted incisor was obtained. (b) The impacted incisor was surgically exposed with a lingual button bonded on lingual surface. FIGURE 4. The root apex of the impacted teeth was palpable under the mobile mucosa of the labial sulcus. FIGURE 2. Pretreatment (a) periapical and (b) panoramic radiograph showing impacted maxillary incisor. (c) Pretreatment cephalometric radiograph showing dilaceration of impacted maxillary incisor. Angle Class II molar relationship, with an overbite of one mm and an overjet of two mm. The arch length discrepancy was 3 mm in the maxillary arch and zero mm in the mandibular arch, as calculated from Moyers prediction tables. Hellman s dental developmental stage was III B. Analysis of the lateral cephalometric radiograph revealed normal values according to Japanese standards. 8 The panoramic and periapical radiographs demonstrated an impacted max-

3 134 UEMATSU, UEMATSU, FURUSAWA, DEGUCHI, KURIHARA FIGURE 5. (a) Periapical radiographs after root canal filling. (b) Panoramic radiograph after apicoectomy. illary right central incisor (Figure 2a,b). The incisor was positioned horizontally and appeared dilacerated with an angle of approximately 90 between the root and crown on the lateral cephalometric radiograph (Figure 2c). Several possible treatment options were explained to the patient and her parents, including (1) extraction of the impacted central incisor, closure of the space, and alignment of the lateral incisor in place of the central incisor; (2) extraction of the impacted central incisor and restoration with a bridge or an implant; and (3) orthodontic space opening for the impacted central incisor and traction of the impacted tooth. Although it is generally considered that a severely dilacerated impacted incisor has a poor prognosis, we decided to expose the tooth and bring it into the arch orthodontically because the patient and her parents requested nonextraction treatment. The treatment plan consisted of orthodontic space opening, surgical exposure, and traction of the impacted dilacerated central incisor into proper position. Treatment progress Bands were placed on the maxillary first permanent molars, and headgear was used for correction of the molar relationship and space maintenance. After distal movement of the first molars was achieved, a palatal arch was placed on the maxillary first molars. When the patient was 12 years old, slot straight wire appliances were placed on the three maxillary permanent incisors, canines, and premolars. The initial leveling was performed FIGURE 6. (a) Posttreatment photograph. (b) Panoramic radiograph. (c) Periapical radiograph. with a inch Ni-Ti wire, followed by a inch stainless steel wire with an open coil spring in the position of the right central incisor. By activating the open coil spring, adequate space for aligning the impacted incisor was obtained (Figure 3a,b). The patient was transferred to the oral surgeon for exposure of the impacted incisor. The surgeon did not raise a wide mucoperiosteal flap similar to that described in the closed-eruption technique by Vermette et al. 9 Instead, the overlying mucoperiosteum and follicle of the lingual surface were elevated to a minimum extent necessary to permit hemostasis and to bond a small button. The alveolar bone layer and follicle of the labial surface were kept intact. An attachment was bonded to the lingual surface of the impacted tooth during surgical exposure. Two

4 IMPACTED MAXILLARY INCISOR WITH DILACERATED ROOT 135 FIGURE 7. (a) Intraoral photographs at six years after treatment. (b) Panoramic radiograph. (c) Periapical radiograph. weeks later, orthodontic traction of the impacted incisor was initiated. A force of approximately 90 g was applied by an elastic chain. The lingual button was removed, and a bracket was bonded when the incisor reached the occlusal plane. The root apex of the impacted tooth could be palpated just beneath the mobile mucosa of the labial sulcus (Figure 4), and the patient complained of spontaneous pain at the area. The cephalometric radiograph revealed root apex exposure. The patient was transferred to the endodontist and the oral surgeon for root canal filling and apicoectomy (Figure 5a,b). Four months later, orthodontic treatment was restarted. The total duration of orthodontic treatment, including final alignment, was 26 months. The bands and brackets were removed, and a bonding wire was attached to the upper incisors with a wraparound retainer. After 16 months of retention, the bonded wire was removed. RESULTS The impacted right maxillary central incisor was successfully aligned in proper position. The repositioned incisor had an acceptable gingival contour and width of attached gingiva (Figure 6a). The posttreatment radiograph showed no root resorption or periodontal bone loss (Figure 6b,c). At follow-up, two years after removal of the bonded wire, the repositioned incisor did not exhibit any relapse or gingival recession at its labial margin, and it maintained the same clinical crown height as the left central incisor. After six years of retention, the patient was examined (Figure 7a through c). The periodontal status of the previously impacted central incisor and the contralateral central incisor was assessed as reported by Becker et al. 10 No differences in oral hygiene or inflammation levels were observed. Probing depth was examined with a standard periodontal probe at the mesiolabial, midlabial, distolabial, mesiopalatal, midpalatal, and distopalatal surfaces of each tooth. Both the width of the attached gingiva and the clinical crown length were measured according to the methods described by Becker et al. 10 Although the attached gingiva of the impacted incisor was slightly shorter than the contralateral central incisor, there were no significant differences in the probing depth and clinical crown length. DISCUSSION Several reports have indicated that an impacted tooth can be brought to proper alignment in the dental arch. 2,3,5 7 The following factors are used to determine whether successful alignment of an impacted tooth can take place: (1) the position and direction of the impacted tooth, (2) the degree of root completion, (3) the degree of dilacerations, and (4) the presence of space for the impacted tooth. Holland 11 has recommended that the movement axis of the impacted tooth must be within 90. Few cases of successful treatment of impacted maxillary incisors with severe dilaceration have been reported to date. 6,12,13 Lin 2 presented a successful case

5 136 UEMATSU, UEMATSU, FURUSAWA, DEGUCHI, KURIHARA of a dilacerated maxillary incisor and pointed out that the success rate of an impacted dilacerated tooth depends on the degree of dilaceration, stage of root formation, and position of the tooth. In the present case, the impacted incisor had a dilacerated root at a right angle (90 ), positioned at a higher level in the alveolar bone (Figure 2c). The angle between the crown long axis and palatal plane was 220. Orthodontists may generally opt to extract such a tooth because of difficulties in its management. Most patients probably would choose extraction and replacement by prosthesis. However, if extraction of the impacted central incisor and restoration with a bridge or an implant is planned, orthodontic traction of that tooth into the proper position should be performed initially to improve esthetics and to achieve and maintain an acceptable bone height. Lin 2 suggested that the treatment approach requires the cooperation of the orthodontist, oral surgeon, and prosthodontist. In the present case, the orthodontist, oral surgeon, and endodontist discussed the treatment plan before the orthodontic treatment was initiated. Therefore, good results were obtained after root canal filling and apicoectomy (Figure 5a,b). The present case did not use the closed-eruption surgical technique, 9 which elevates a flap and returns it to the original location after placing an attachment on the impacted tooth. The oral surgeon removed a minimum area of buccal mucosa to locate the tip of the impacted incisor but retained the connective tissue follicle of the labial surface to permit hemostasis. From our results, we suggest that the labial epithelial attachment on the impacted incisor should be retained so that the repositioned incisor would present an acceptable gingival contour and attached gingiva. CONCLUSIONS Surgical exposure and orthodontic retraction of a severely dilacerated impacted incisor is a clinical challenge. Although treatment included apicoectomy, the severely dilacerated incisor was successfully positioned, and the repositioned incisor showed good stability. REFERENCES 1. Becker A. Early treatment for impacted maxillary incisors. Am J Orthod Dentofacial Orthop. 2002;121: Lin YTJ. Treatment of an impacted dilacerated maxillary central incisor. Am J Orthod Dentofacial Orthop. 1999;115: Archer LE. Composites. Oral and Maxillofacial Surgery. 5th ed. Philadelphia, Pa: WB Saunders Company; 1975: Bishara SE. Impacted maxillary canines: a review. Am J Orthod Dentofacial Orthop. 1992;101: Wasserstein A, Tzur B, Brezniak N. Incomplete canine transposition and maxillary central incisor impaction a case report. Am J Orthod Dentofacial Orthop. 1997;111: Kolokithas G, Karakasis D. Orthodontic movement of dilacerated maxillary central incisor. Am J Orthod. 1979;76: Tanaka E, Watanabe M, Nagaoka K, Yamaguchi K, Tanne K. Orthodontic traction of an impacted maxillary central incisor. J Clin Orthod. 2001;35: Sakamoto T. A study on the development changes of dentofacial complex of Japanese with special reference to sella turcica [in Japanese]. J Jpn Orthod. 1959;18: Vermette ME, Kokich VG, Kennedy DB. Uncovering labially impacted teeth: apically positioned flap and closed-eruption technique. Angle Orthod. 1995;65: Becker A, Brin I, Ben-Bassat Y, Zilberman Y, Chaushu S. Closederuption surgical technique for impacted maxillary incisors: a postorthodontic periodontal evaluation. Am J Orthod Dentofacial Orthop. 2002;122: Holland DJ. The surgical positioning of unerupted, impacted teeth. Oral Surg Oral Med Oral Pathol. 1956;9: Stewart DJ. Dilacerated unerupted maxillary central incisors. Br Dent J. 1978;145: Smith DMH, Winter GB. Root dilacerations of maxillary incisors. Br Dent J. 1981;150: