Morphometric analysis of craniofacial skeletal and masticatory muscle morphology in patients with temporomandibular disorders: An observational study.

PURPOSE: This study evaluated craniofacial skeletal and masticatory muscle morphology in patients with temporomandibular disorders (TMD), compared these features between dislocation/subluxation and internal derangement subgroups, assessed muscle-bone relationships, and explored potential anatomical factors relevant to future TMD risk-assessment models. METHODS: A prospective cross-sectional observational study was conducted in 79 patients with TMD, including 27 with dislocation/subluxation (Group I) and 52 with internal derangement (Group II). Craniofacial skeletal measurements and cross-sectional areas (CSA) of the masticatory muscles were assessed on non-contrast computed tomography (NCCT) face. Measurements were compared with published reference values and between the two groups. Statistical analysis included descriptive statistics, t-tests, and Pearson correlation (α = 0.05). RESULTS: Coronoid process length and angulation were significantly reduced in both groups (P < 0.0001), with lower values in Group I than Group II (P < 0.0001). Temporalis muscle CSA was decreased, whereas lateral pterygoid muscle CSA and pterygoid plate length were increased predominantly in internal derangement. In Group I, temporalis CSA correlated strongly with coronoid length (r = 0.74) and angulation (r = 0.70). Lateral pterygoid muscle CSA demonstrated significant positive correlations with lateral pterygoid plate length in both Group I (r = 0.39) and Group II (r = 0.48). CONCLUSION: Distinct craniofacial skeletal and masticatory muscle patterns were observed across the TMD subgroups. The observed differences and muscle-bone relationships provide further insight into the anatomical variations associated with TMJ dysfunction and may support future studies investigating their relevance in assessment, risk evaluation, and individualized management.