Abstract
The relationship between the function of whole body and static occlusion has been reported in many articles; however, it still remains unknown whether clenching —which is one of the dynamic occlusal functions— exerts an influence on the whole body.
In this study, the shifting of the gravity center with mandible at resting position, in occlusion and in clenching with voluntary occlusal force was measured to investigate whether or not the mechanism of physical adjustment of equilibrium was affected by the alteration of mandibular position. The following results were obtained:
1. In the testing with eyes closed, the-distance and velocity of the shifting of the gravity center tended to be relatively smaller with the mandible in occlusion and when clenching in the intercuspal position with 10% and 50% of occlusal force than when the mandible was kept at resting position or clenched with 100% occlusal force.
2. The extent of shifting tended to be smaller —except in one subject— when the mandible was occluded, clenched with 10% occlusal force and cle nched with 50% occlusal force.
3. The center of gravity tended to be displaced on the whole towards the posterior direction.
4. Slight alteration of mandibular position at rest and in occlusion did not produce significant differences in the shifting of the gravity center.
