An evaluation of condylar and ramal vertical asymmetry in adolescents with unilateral and bilateral posterior crossbite using cone beam computed tomography (CBCT).

Aims: The primary purpose was to evaluate condylar and ramal vertical asymmetry in adolescent patients displaying unilateral posterior (UCB) and bilateral posterior crossbite (BCB) malocclusions. A secondary aim was to compare the findings with a matched control group exhibiting normal occlusion (CG) using cone beam computed tomography (CBCT).

Material and methods: The study groups consisted of (1) 30 patients (Mean age: 14.49 +/- 1.91 years) with a UCB, (2) 29 patients (Mean age: 14.57 +/- 1.84 years) with a BCB, and (3) 36 patients (Mean age: 14.24 +/- 2.42 years) as a matched control group (CG). Condylar, ramal, condylar-plus-ramal height and index measurements were performed using CBCT images following the method of Habets et al. A paired t-test was performed for side comparison in each group. Oneway ANOVA (Analysis of Variance) was used to determine statistically-significant differences between the groups for asymmetry index measurements and Tukey's HSD test was employed for individual group differences.

Results: There was no statistically significant difference in condylar height (CH), ramal height (RH), and condylar plus ramal height (CH + RH) measurements between the right and left sides of the UCB group and CG, except for the RH in the BCB group (p = 0.045). Tukey's HSD test showed that the ramal asymmetry index (RAI) and the condylar plus the ramal asymmetry index (CRAI) were statistically significantly different between the UCB and BCB groups (p = 0.035 and p = 0.015, respectively).

Conclusions: Although the condylar asymmetry index (CAI) values were found to be high in the groups of UCB (13.84 +/- 11.33), BCB (9.38 +/- 8.56), and CG (10.58 +/- 9.48), the comparisons amongst the groups were not statistically significant. The asymmetry between the UCB and BCB groups was observed for RAI and CRAI values, rather than CAI values.