Comparison of condylar size among different anteroposterior and vertical skeletal patterns using cone-beam computed tomography.

Abstract

To compare condylar size among different anteroposterior and vertical skeletal patterns using cone-beam computed tomography (CBCT). The study included 166 subjects (61 men, mean age: 27.2 ± 7.6 years; 105 women, mean age: 27.4 ± 9.2 years). The anteroposterior skeletal patterns of the subjects were classified into Classes I (-1° ≤ A point-nasion-B point angle [ANB] < 4°), II (ANB ≥ 4°), and III (ANB < -1°). The vertical skeletal patterns were classified into hypodivergent (mandibular plane [MP] ≤ 23°), normodivergent (23° < MP < 30°), and hyperdivergent (MP ≥ 30°) groups. The condylar length, height, and width were examined using CBCT images. Analysis of covariance was used to compare three condylar size measurements among the three anteroposterior groups and the three vertical groups using sex as a covariate. Both left and right sides were examined. Nine groups were further divided according to the anteroposterior and vertical groups, and two-way analysis of covariance (ANCOVA) was applied to estimate the composite effect of skeletal patterns in both directions. Sex as a covariate showed statistical significance in most examinations. The condylar height on both sides had statistically different anteroposterior skeletal patterns ( P < .001). The condylar width on both sides also had statistically different vertical skeletal patterns ( P < .001). After adjusting for sex, the condylar height and width on both sides increased from Class II, Class I, and Class III. The condylar width on both sides increased from the hypodivergent group, the normodivergent group, and the hyperdivergent group. No composite effect of skeletal patterns in both directions was observed. Condylar height and width considerably differed among subjects with different anteroposterior or vertical skeletal patterns. The anteroposterior or vertical skeletal patterns independently affected the condylar size.