Dental Vertical Height, Occlusal Plane Angles And Temporomandibular Joint Morphology

This study was aimed to investigate the correlations between the dental vertical dimension, occlusal plane angles and temporomandibular joint (TMJ) morphology in adults with skeletal Class II malocclusion using cone beam computed tomography (CBCT). A total of 105 skeletal class II patients were divided into three groups according to the FH-MP angle (hypodivergent, normodivergent and hyperdivergent), with 35 skeletal Class I normodivergent patients serving as controls. The dentoalveolar height, posterior occlusal plane angle (FH-POP), mandibular occlusal plane angle (FH-MOP) and TMJ measurement items were measured. Skeletal II hyperdivergent patients exhibited the steeper FH-POP and FH-MOP, larger U1-PP, L1-MP, U6-PP and L6-MP, shorter condylar mediolateral diameters and anteroposterior diameters, smaller condylar inclination angle, smaller anterior and superior joint space. While, Skeletal II hypodivergent patients owned the opposite trend. In hypodivergent patients, FH-POP was weakly correlated with U7-PP. In skeletal Class II hyperdivergent patients, FH-POP was weakly correlated with U7-PP, and FH-MOP was weakly correlated with U1-PP, L6-MP and L7-MP. U7-PP and L6-MP had a moderate correlation with condylar morphological indicators, whereas in hyperdivergent patients, U6-PP, U7-PP, L6-MP, L7-MP and L1-MP had a moderate correlation with condylar morphological indicators. There was a significant difference in L6-MP between the skeletal Class II hyperdivergent and hypodivergent patients. And L6-MP was the most closely related to the TMJ morphology in two groups.