Non-pathological facial asymmetry in adult women: an approach to bite force, occlusal contact distribution and masticatory muscle thickness.

Abstract

Facial asymmetries, often subtle, can indicate imbalances that go beyond aesthetic concerns.

Aim: This cross-sectional study analyzed molar bite force, occlusal contact distribution, and masseter and temporal muscle thickness in adult women with facial symmetry and slight non-pathological facial asymmetry, which generally goes unnoticed and is often considered a variation of normality.

Materials and method: Forty-two women aged 18 to 30 were evaluated for slight non-pathological facial asymmetry using the VECTRA M3. Two groups were established: facial symmetry (n=21) and slight non-pathological facial asymmetry (n=21). Molar bite force was measured with a dynamometer. T-Scan was used to evaluate occlusal contact distribution. Masseter and temporal muscles thickness was assessed using ultrasound. Analyses used a 5% significance level (Student's t-test).

Results: No significant difference was found in maximum molar bite force between the groups, though the slight asymmetry group showed lower force in clinical observation. No significant difference was observed in masseter and temporal muscle thickness during rest and maximum voluntary contraction, but clinically, the masseter was thicker than the temporal in both groups, being thicker in the slight non-pathological facial asymmetry group than in the facial symmetry group. Occlusal contact distribution did not differ significantly between groups, but clinically, the slight non-pathological facial asymmetry group showed less distribution in the occlusal contacts of the first permanent molars and more pronounced distribution in the left hemiarch compared to facial symmetry group.

Conclusion: Although no significant difference was observed between groups in this study, the numerical analysis of the results highlights the importance of evaluating the stomatognathic system in dental procedures, particularly with regard to non-pathological facial asymmetry.