Three-dimensional localization of maxillary canines with cone-beam computed tomography

Introduction: Precise 3-dimensional (3D) localization of impacted canines is central to their clinical management. Recently introduced dental 3D volumetric imaging systems make precise localization possible. The purpose of this study was to describe the spatial relationship of impacted canines by using images obtained with the NewTom QR-DVT 9000 (QR Srl, Verona, Italy). Methods: Unilaterally and bilaterally impacted canines (n = 27) from 19 consecutive patients (15 female, 4 male) were evaluated on images taken with the NewTom QR-DVT 9000. The spatial relationships of the impacted canines relative to adjacent structures and incisor resorption were assessed with 3D visualization software. Results: Most (92.6%) of the 27 impactions were palatal. Incisor resorption adjacent to the impacted canine was present in 66.7% of the lateral incisors and 11.1% of the central incisors. Follicle size did not play a major role in influencing impacted canine position. The alveolus was narrower at the impacted canine side compared with the erupted canine side; however, the width of the alveolus on the impacted canine side is independent of the deciduous canines. A correlation was found between the proximity of the impacted canine to the incisors and their resorption. There was no common location where eruption was arrested, and great variation in the inclination of the impacted canine was found. Conclusions: 3D volumetric imaging of impacted canines can show the following: presence or absence of the canine, size of the follicle, inclination of the long axis of the tooth, relative buccal and palatal positions, amount of the bone covering the tooth, 3D proximity and resorption of roots of adjacent teeth, condition of adjacent teeth, local anatomic considerations, and overall stage of dental development. In short, 3D imaging is clearly advantageous in the management of impacted canines.