A Three Dimensional Displaying Method for Tooth Grinding Curved Surfaces and Pathways during Chewing Movements

Mandibular movements are coordinated ones caused by TMJ, muscles, dentitions and neuromuscles in stomatognathic system. The pathways in areas of intercuspal position (ICP) during chewing movements which are particularly influenced by dentitions were investigated. An evaluation of these movements will contribute to establising a functional diagnosis method.An objective assessment fitting the regression line to sample data on pathways in areas of ICP during chewing movements was also reported. In addition to these studies, we developed a system to measurement of mandibular movements during grinding movement utilizing visual feedback system.In this study, it became possible to establish a new displaying method for tooth grinding curved surfaces and pathways during chewing movements by applying algorithms of perspective transformation, hidden line elimination and coordinate transformation to incisal 3-dimensional data (X, Y, Z) obtained from a Sirognathograph (SGG).The results were as follows.:1. Tooth grinding curved surfaces were constructed as the wire frame model.2. Pathways in areas of ICP during chewing movements were displayed on the tooth grinding curved surfaces.3. A new method makes possible to display the relation between tooth grinding curved surfaces as anatomical information and pathways in areas of ICP chewing movements as functional information.