The relationship between local alveolar bone housing and size of canine in maxillary canine-lateral incisor transposition: A retrospective cone-beam computed tomography-based study.

INTRODUCTION: This study aimed to use 3-dimensional data to analyze the relationship between local alveolar bone housing and canine size in maxillary canine-lateral incisor transposition. METHODS: Cone-beam computed tomography study data from 31 patients with maxillary canine-lateral incisor transposition were imported into Dolphin Imaging software (version 11.8; Dolphin Imaging and Management Solutions, Chatsworth, Calif) for measurement. The buccal and palatal alveolar thickness of lateral incisor roots at different heights, the maximal thickness of displaced canine, and canine height were measured. Alveolar height-thickness variation curves at the lateral incisor region and maximal thickness of displaced canine were plotted to calculate the appropriate theoretical minimum alveolar heights of total alveolar housing, buccal alveolar housing after concentrating the bone buccally (TMAH-B1), and original buccal alveolar housing (TMAH-B2) required for correcting the transposition of 2 teeth. RESULTS: Canines could only be moved distally above lateral incisors in 5 patients. The mean value of theoretical minimum alveolar heights of total alveolar housing was 14.57 ± 1.75 mm. It was possible to reposition canines distally by concentrating the alveolar bone buccally in the remaining 26 patients. The mean value of TMAH-B1 was 10.86 ± 3.70 mm. Canines could be repositioned distally directly over the buccal aspect of the lateral incisor in 17 patients. The mean value of TMAH-B2 was 9.30 ± 2.35 mm. Canine height was greater than TMAH-B1 in 18 patients; however, only 10 patients were greater than TMAH-B2. CONCLUSIONS: Correction of transposition was difficult in some patients because of the lack of alveolar bone housing. Repositioning was possible when the height of the canine was higher than a certain height. An accurate assessment of the relationship between alveolar housing and tooth size is recommended.