Correlation between inclination of occlusal plane and masticatory movement

Objectives: The purpose of this study was to investigate the relationship between the inclination of the occlusal plane and masticatory movement. Methods: Masticatory movements of 41 young adults were measured using the three-dimensional Mandibular Movement Analyzing System. The inclination of the occlusal plane was measured in the sagittal plane using a three-dimensional digitizer. Results: In the sagittal plane, the masticatory closing path and the occlusal plane were consistent in maintaining a perpendicular relation with each other regardless of the inter-individual variation of the inclination of the occlusal plane. Subjects with an anteriorly inclined occlusal plane showed a vertical closing path, and subjects with a posteriorly inclined occlusal plane showed a flat closing path in the frontal plane. These characteristics were explained by the variation of the timing on the balancing-side condylar return correlated with the inclination of the occlusal plane. Conclusions: There is a significant correlation between the inclination of the occlusal plane and the direction of the closing path during mastication.