Impact of different malocclusion types on the vertical mandibular asymmetry in young adult sample

The aim of this study was to investigate the vertical mandibular asymmetry in a group of adult patients with different types of malocclusions, based on Angle's dental classification.

A sample of 102 patients (age range 19-28) who went for routine orthodontic treatment in the institution were divided into four groups: Class I, 26 patients; Class II/1, 30 patients; Class III, 23 patients; and control group (CG) with normal occlusion, 23 patients. Condylar asymmetry index (CAI), ramal asymmetry index (RAI), condylar-plus-ramal asymmetry index values were measured for all patients on panoramic radiographs. Data were analyzed using Kruskal-Wallis and Mann-Whitney U-test at the 95% confidence level (P < 0.05).

The results of the analysis showed that different occlusal types significantly affected the vertical symmetry of the mandible at the condylar level. Class I and Class II/1 malocclusion groups showed a significant difference in CAI values relative to the CG (P < 0.05, P < 0.001). No statistically significant difference was found between the CG and Class III malocclusion group (P > 0.05). Comparisons between Class II/1 and Class I malocclusions revealed a significant difference in CAI values (P < 0.01).

Both Class II/1 and Class I malocclusions patients had significantly higher CAI values compared to CG and Class III group. CAI value was significantly higher in Class II/1 malocclusion compared to Class I malocclusion. Both these malocclusions could act as a predisposing factor for having asymmetric condyles if left untreated.