[Relation between dentofacial skeletal patterns and the deflection of the roots of mandibular canine and premolars].

Abstract

We conducted an investigation of the relation between dentofacial skeletal patterns and the deflection of the roots of mandibular canines and premolars. Data on root deflection, rated as mesial, distal, or undeflected, were obtained from orthopantomographs taken of 130 patients who were judged to meet certain criteria on their initial orthodontic examinations. The significance of the relation between these data and the dentofacial patterns, determined by radiographic cephalometric analysis, was then examined statistically. This determined that in cases of severe mandibular prognathism (ANB less than -2 degrees), the roots of 1st and 2nd premolars exhibited significantly more mesial deflection. This result suggests that the mesial deflection of these roots is caused by the differential growth rates of basal and alveolar bone in cases of severe mandibular prognathism.