Correlation analysis between occlusal plane and maxillofacial alterations in Chinese patients with an anterior disc displacement

Objective To study the changes in the vertical and sagittal craniomaxillofacial morphology in Chinese adult patients with bilateral anterior temporomandibular joint(TMJ)disc displacement and to explore their correlation. This may provide valuable insights for clinical diagnosis and treatment planning. Methods Ninety-eight Chinese adult patients were divided into 3 groups: 29 patients in bilateral disc Normal Position group (BN), 33 patients in bilateral Anterior Disc Displacement With Reduction group (ADDWR) and 36 patients in bilateral Anterior Disc Displacement Without Reduction group (ADDWoR). Uceph software was used to measure 6 items of occlusal plane and 13 items of craniomaxillofacial morphology for comparison and correlation analysis between groups. Results Compared to the BN group, subjects with anterior TMJ disc displacement (ADD) were more likely to exhibit a steeper posterior occlusal plane and an extended craniofacial posture with a Class II hyperdivergent pattern characteristics. Nevertheless, there were no statistically significant differences between the ADDWR and ADDWoR groups. The results of Pearson correlation analysis revealed a significant association between a steep occlusal plane in ADD patients and both skeletal mandibular retraction and vertical overgrowth. Conclusion Chinese patients with anterior disc displacement of the TMJ have a steeper posterior occlusal plane and hyperdivergent skeletal Class II malocclusions tendency, which may be associated with occlusal function or condylar remodeling.