Incisor Inclination – Risk Factor for Palatally-impacted Canines

Abstract

The purpose of this study was to evaluate the torque of upper incisors and the maxillary size in sagittal direction in patients with impacted canines. Panoramic radiographs, cephalograms and pretreatment study models were evaluated in 199 patients (12.7 +/- 3.6 years) with impacted canines. The prevalence of malocclusions, inclination of the canine to the occlusal plane, incisors' inclination and maxillary size were determined. 45% of the patients showed symptoms of Class II, Division 2 malocclusion: at 18.5 degrees, the inclination of upper incisors (angle U1/NA) was lower and at 81.3 degrees the SNA angle higher than in patients with neutral conditions. There is no guidance for the erupting canine through the labial root torque of the upper incisors like in patients with missing lateral incisors. Patients with symptoms of Class II, Division 2 malocclusion should be regarded as a risk group for canine impaction.