Root Length and Anatomy of Impacted Maxillary Canines in Patients with Unilateral Maxillary Canine Impaction

Canine impaction is a common occurrence. In this study, we sought to investigate the root anatomy and length of impacted canines and lateral incisor adjacent to impacted maxillary canine.
In this retrospective study, three-dimensional tomographic imaging was performed on 26 patients with unilateral maxillary canine impaction. In this study, we evaluated root length and anatomy of impacted canines, in terms of resorption intensity and curvature, with Planmeca Romexis Viewer 4.0. Furthermore, crown shape as well as root length and anatomy of the lateral incisors adjacent to impacted canines were investigated and compared with the other side on the dental arch, where canine eruption was normal.
Root length of impacted canines was significantly lower than that of normal canines (P=0.011). There were no significant differences between root length of lateral incisors adjacent to impacted canines and root length of lateral incisors adjacent to normal canines (P=0.221). Moreover, the resorption intensity of the adjacent lateral incisors was higher than that of the impacted canines. No significant differences were noted in root resorption intensity between the lateral incisors adjacent to the imacted canines and the lateral incisors adjacent to normal canines (P=0.36). In addition, resorption intensity was significantly higher in impacted canines than in normal canines (P=0.024). Root anatomy of impacted canines was not significantly different from that of normal canines (P=0.055). The crown shape of the lateral incisors adjacent to impacted canines was not significantly different from that of the lateral incisors adjacent to normal canines (P=0.052).
Impaction can probably affect root length and canine resorption severity. However, root and crown shape of lateral incisors cannot always be associated with canine impaction.