[Mechanical response of temporomandibular joint induced by occlusal change]

The purpose of this research was to investigate the mechanical effects on the temporomandibular joint influenced by the occlusal variations: the inclination of the upper incisor and the change of occlusal contacted position on the lower occlusal surface. For this purpose a theoretical study and a model experiment were performed. In the theoretical study, the Rigid Body Spring Model was applied to the temporomandibular joint for analyzation of the stress distribution and movement of the condyle head under the various conditions of the joint. Furthermore, the model experiment could be performed to confirm three-dimensionally the findings attained by the theoretical study. The results were as follows: 1. In the phase of the decreasing upper incisor inclination excessively, the direction of the temporomandibular joint force was be rotated counterclockwise and the magnitude of the joint force was be increased. 2. The movement of the condyle head (distance and direction) and the stress distribution of the disk were influenced by the various shapes of the joint and the mechanical properties of the surrounding soft tissues.