Influence of protrusive tooth contact on tapping point distribution

This study investigated the influence of protrusive tooth contacts (tooth contacts during mandibular protrusion) on the tapping point distribution. Nine healthy subjects volunteered for this study and the protrusive tooth contact pattern, as well as the retrusive tooth contact pattern, was altered on four maxillary occlusal splints. The first splint was adjusted to make the sagittal incisal path of protrusion and retrusion equivalent to that of the natural dentition. The second and third splints had partial and complete elimination of the protrusive tooth contact, respectively. The fourth splint had complete elimination of both protrusive and retrusive tooth contacts. The subjects were asked to use each splint continuously for 1 week. The tapping point distribution was measured on the 7th day after insertion of each splint. The four experimental occlusal conditions were found to have a significant effect on the tapping point distribution. The complete elimination of the protrusive tooth contact caused an anterior tapping point location and an increase in the tapping point area. The former tendency was found to be independent of the presence of the retrusive tooth contact. In conclusion, it was suggested that the protrusive tooth contact plays a significant role in maintaining the consistency and stability of the tapping point.