Crown Size Comparisons in Patients with Unilateral Palatally Impacted Canine by Cone-Beam Computed Tomography

Objective: Impacted canine is a frequently encountered clinical problem. The goal of this study is to compare canines’ dimensions and the adjacent lateral incisors to investigate the impact of tooth size on canine impaction as it could help the orthodontists to prepare a scientific treatment plan which proportionally aligns the teeth on both sides. Methods: In this retrospective study, the cone-beam computed tomography of 40 patients with unilateral palatally impacted canines from the Kurdish population was assessed. Individual linear measurements were obtained from multiple axial slices of cone-beam computed tomography to assess mesiodistal width, gingivoincisal height, and labio-palatal thickness of the upper maxillary canines and lateral incisors crowns. The achieved data were compared between the impacted and non-impacted sides and a ratio of lateral incisor/canine for each dimension was calculated. Results: The crowns of maxillary impacted canines were significantly larger labio-palatally and mesiodistally than the canine on the normally erupted side. While lateral incisor crowns adjacent to the impacted canines were shorter gingivoincisally than those adjacent to non-impacted canines. There was a significant association between the erupted lateral incisor and higher gingivoincisal meanwhile no significant difference was observed in labio-palatal and mesiodistal dimensions. Conclusions: Palatally impacted canines were significantly larger in labio-palatal and mesiodistal dimensions than the normally erupted canines. The maxillary lateral incisors in the impacted canine side were slightly shorter than those on the non-impacted side and this difference has an effect on the orthodontic treatment planning.