Objectives: This study assessed the difference in soft tissue deviations of the nose, lip, and chin among different mandibular asymmetry types of Class III patients.
Methods: Cone-beam computed tomography data of 90 Class III patients with moderate-to-severe facial asymmetry were investigated. The sample was divided into three groups based on the extent of mandibular rolling, yawing, and translation. Soft tissue landmarks on the nose, lip, and chin were investigated vertically, transversely, and anteroposteriorly. Paired t-test was performed to compare the variables between the deviated (Dv) and nondeviated (NDv) sides, and one-way analysis of variance with Tukey post-hoc test was performed for intergroup comparisons. Pearson’s correlation coefficient was calculated to assess the relationship between soft and hard tissue deviations.
Results: The roll-dominant group showed significantly greater differences in the vertical position of the soft tissue landmarks between the Dv and NDv than other groups (p < 0.05), whereas the yaw-dominant group exhibited larger differences in the transverse and anteroposterior directions (p < 0.05). Moreover, transverse lip cant was correlated with the menton (Me) deviation and mandibular rolling in the roll-dominant group (p < 0.001); the angulation of the nasal bridge or philtrum was correlated with the Me deviation and mandibular yawing in the yaw-dominant group (p < 0.01).
Conclusions: The three-dimensional deviations of facial soft tissue differed based on the mandibular asymmetry types in Class III patients with similar amounts of Me deviation. A precise understanding of soft tissue deviation in each asymmetry type would help achieve satisfactory facial esthetics.

Keywords: Facial asymmetry, Soft tissue deviation, Mandibular asymmetry type, Cone-beam computed tomography