Associations between palatally displaced canines and maxillary lateral incisors.

INTRODUCTION

The purpose of this research was to investigate relationships among the location and orientation of palatally displaced canines and the dimension and orientation of the maxillary lateral incisor.

METHODS

An experimental group of 40 patients with 46 palatally displaced canines (20 from boys, 26 from girls; mean age of the subjects, 13.9 years; age range, 10.5-15.9 years) was selected from the records of patients referred to a radiology practice specializing in cone-beam volumetric tomography imaging. This group was age- and sex-matched with 30 normal subjects with 60 canines (26 from boys, 34 from girls; mean age of the subjects, 13.8 years; age range, 10.4-15.7 years). Digital cone-beam volumetric tomography images were imported into an imaging software and were reoriented and reconstructed into several radiographic images in coronal and sagittal sections; a maxillary arch occlusal view was also produced. The angular and linear variables of the canines and the maxillary lateral incisors were measured by using software measurement tools. Independent t tests or Mann-Whitney U tests were used accordingly based on normality of the data to compare the variables between the palatally displaced canine and the control groups. Multiple linear regressions were used to examine the relationships between the canine variables (dependent variables) and the maxillary lateral incisor variables together with confounding variables (independent variables).

RESULTS

The maxillary lateral incisors in the palatally displaced canine group tended to be more upright in the sagittal and coronal planes. Generally, the most significant independent variables according to backward examination of linear regression for canine variables (coronal and sagittal angulations, and distance to the occlusal plane of palatally displaced canines) were the coronal and sagittal angulations of the maxillary lateral incisors, the length and buccolingual root width of the maxillary lateral incisors, and age.

CONCLUSIONS

The orientation and location of palatally displaced canines were associated with changes in the angulations of maxillary lateral incisors and small lateral incisors.