Abstract: Objective: To judge the correlation between the mesiodistal and vertical position of the maxillary impacted canines on the panoramic radiographs and the labiopalatal position of the impacted canines and root resorption of permanent incisors in cone-beam computed tomography (CBCT). Methods: Sixty-eight patients with ninety-four impacted maxillary canines were scanned by CBCT and the panoramic radiograph. We divided the mesiodistal position of the canine cusp tip on the panoramic radiographs into five sectors (Ⅰsector-Ⅴsector), and in the vertical plane the height of the crown of each impacted canine was classified three zones (apical, middle, or coronal). The labiopalatal position of the impacted canines and root resorption of permanent incisors were evaluated with CBCT. Results: There was a statistically significant association between the labiopalatal position of the canines and the panoramic sectors of the impacted canines (P＜0.001). In CBCT labially impacted canines were more frequent in panoramic sectors Ⅰ, Ⅱ, Ⅲ, mid-alveolus impacted canines were frequent in sector Ⅳ, and palatally impacted canines were most frequent in sector Ⅴ. But the panoramic vertical zones of the impacted canines and the labiopalatal position in CBCT were no statistical significance. Root resorption of permanent incisors was more frequent in panoramic sectors Ⅳ,Ⅴand apical zone, middle zone. Root resorption of permanent incisors showed a significant difference according to sector location and zone location (P＜0.05). Conclusion: The labiopalatal position of impacted canines and resorption of permanent incisors might be predicted using sector location on panoramic radiography. The vertical zone on panoramic radiography can judge the root resorption of permanent incisors, but can not predict labiopalatal position of impacted canines.

Key words: Maxillary impacted canines, Panoramic radiography, Cone-beam computed tomography