Abstract
Many studies have been made on the incisal movement pattern during mastication. However, little information is available concerning the movements of molars, in which area masticatory movement is performed. The purpose of this study was to clarify the distribution of masticatory patterns at each incisal, working-side, and non-working-side molar point, focusing on the relationship among these three points. Masticatory movements were measured on 50 normal young adults using the3-D Mandibular Movement Analyzing System. Computerized analysis was performed and the averaged paths of the incisal, working-side, and non-working-side molars were calculated for each subjects. Each averaged path was divided into four patterns according to the location of opening and closing paths in frontal and sagittal planes, respectively. The frontally-viewed masticatory pattern was the same among incisal, working-side, and non-working-side molars in almost all subjects. On the other hand, the distribution of the sagittally-viewed masticatory pattern was significantly different among incisal, working-side, and non-working-side molars (x2 test, p<0.05). Only 30% of the subjects showed consistent masticatory patterns among these three points.
