Influence of the inclination of the plate of an intra-oral tracing device on the condylar position registered by tapping movement

The object of this study was to determine the best inclination of the intra-oral tracing device to get optimum condylar position with the registration of tapping movement. Three appliances with different tracing plate inclinations were used in five healthy subjects. The tracing plates were set at 0 degrees to occlusal plane (horizontal); at the angle formed by drawing a line from condylar point to the stylus position at occlusal plane (inclined); then at the angle half to inclined (half-inclined). Subjects made Gothic arch and tapping movements (n = 30) at a 30 mm interincisal distance with the head Camper plane horizontal. The incisal and condylar points were tracked with a 6-degree-of-freedom jaw movement tracking system. The location of gothic arch apex, the distribution and mean position of 30 tapping points from intercuspal position were analyzed in incisal and condylar point between the appliances. Data were analyzed with repeated measures one-way anova. Results showed that mean position of tapping points were significantly different among the appliances. Half-inclined appliance recorded tapping points in a convergent area nearer to intercuspal position (IP) than other appliances. In all appliances, the contact points of the tapping movement were anterior to Gothic arch apex.