Vector analysis of three-dimensional occlusal forces on mandibular premolars and molars in normal adults

Abstract

We analyzed the three-dimensional occlusal force vectors during intercuspation in normal adults. Silicone occlusal registration and pressure-sensitive sheets were recorded for ten subjects during clenching with medium force and maximum force. A non-contact, three-dimensional measuring device digitized the silicone occlusal registration and occlusal forces were measured using pressure-sensitive sheets. After the occlusal contact position had been identified, the three-dimensional occlusal force pattern was synthesized from the data. The contact points, contact areas, resultant forces and moments for the molars were significantly different from those for the premolars. The inclination of resultant forces were almost vertical to the occlusal plane in the frontal and sagittal view. There was also a significant difference in the contact points, contact areas, resultant forces and moments when clenching with medium force was compared with clenching with maximum force. However, there was no consistant tendency in the inclination of the resultant forces.