Position of impacted canines and lateral incisors, and factors associated with unerupted canines

Abstract

Aim: The aim is to determine the impact of unerupted canine position on the position of adjacent teeth as well as the relationship of the severity of canine impaction and position, and associated factors of the impaction. Material and method: From CBCTs of the patients treated between 2015 and 2020 at the Department of Orthodontics of St.Anne’s University Hospital 39 scans with unilateral impacted upper canine were selected. There were 25 palatally impacted canines, 14 vestibularly impacted canines. The parameters measurements were carried out with Invivo6 software after setting of the reference planes. Results: Factors associated with canines impaction were proved, such as shift of the midline towards the affected side (by 0.56–0.68 mm), higher incidence of peg shaped lateral incisor (I2) in palatally impacted canines, narrower palate on the side of impacted canine (by 1 mm in palatally and 2 mm in vestibularly impacted canine). In vestibularly impacted canines lateral incisors (I2) were significantly more distally inclined (by 10.3°), in palatally impacted canines lateral incisors (I2) were distorotated by 14.1°and retruded by 7.2°. In vestibularly impacted canines the roots of I2 were shortened by almost 2 mm, in palatally impacted canines by 1 mm. On the side of impacted canines we found higher incidence of bent roots (51.3%) and hooks (12.8%); I2 bent roots were more frequent on the side of palatally impacted canines (32%). Conclusion: The study findings could help in early diagnostics – either clinical or radiological – of impacted upper permanent canines, and in adopting the best strategy of treatment. Disturbed development of impacted canines (shorter length, bent root) calls for early detection and timely orthodontic treatment of the impaction.