Direction-Dependent Soft Tissue Thickness in Facial Asymmetry: A Three-Dimensional Analysis Using Facial Scanning and Cone Beam Computed Tomography
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Abstract
Background: Facial asymmetry is a common craniofacial condition affecting facial aesthetics and function. Although skeletal discrepancies are the primary determinant, the role of direction-dependent soft tissue thickness in shaping facial morphology remains unclear. Objective: To investigate directiondependent patterns of soft tissue thickness in patients with facial asymmetry using integrated three-dimensional facial scanning and cone beam computed tomography. Materials and methods: This cross-sectional study included 60 adults aged 18–35 years undergoing orthodontic and orthognathic evaluation. Cone beam computed tomography and three-dimensional facial scan datasets were fused to construct composite craniofacial models. Bilateral skeletal landmarks were identified, and soft tissue thickness was measured relative to the midsagittal plane in transverse and sagittal directions. Paired statistical tests compared measurements between deviated and contralateral sides. Results: Significant skeletal asymmetry was observed at multiple craniofacial landmarks, particularly at the antegonial notch (2.09 ± 4.40 mm), orbitale (1.66 ± 3.16 mm), and anterior ramus notch (1.34 ± 1.94 mm), among others (P < 0.01). Direction-dependent patterns of soft tissue thickness was identified. In the transverse, soft tissue was generally thinner on the deviated side at the anterior ramus notch, canini, antegonial notch, and gonion (P < 0.01). In contrast, sagittal measurements showed greater soft tissue thickness on the deviated side at the condylion, antegonial notch, and gonion (P < 0.01). Conclusion: Soft tissue thickness in facial asymmetry demonstrates direction-dependent patterns and only partially reflects skeletal deviations. Integrated three-dimensional imaging may improve evaluation of skeletal–soft tissue relationships and assist orthodontic and orthognathic treatment planning.
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