Relationship between Amount of Incisal Point Movement and Variations of Path in Chewing

Abstract

Purpose: The purpose of this experiment was to clarify the effect of amount of masticatory movement on variation of path of mandibular incisor point.Methods: Forty healthy subjects were asked to chew softened chewing gum on their habitual side. For the 10 cycles from the fifth cycle of mastication, the opening distance (amount of vertical movement) and the masticatory width (amount of lateral movement) as the indicators representing the amount of masticatory movement, and the standard deviations of the lateral opening, lateral closing, and vertical compoments as indicators representing the variations of the masticatory path were calculated. The relationship between the indicators for the amount of movement and indicators for variations of the masticatory path were investigated.Results: The values of indicators for variations of the masticatory path were large when the opening distance was large, and there was a significant positive correlation between the two (r=0.508-0.685, P<0.01). There was no correlation between the masticatory width and the indicators for variations of the masticatory path.Conclusion: From these results it was concluded that variations of the masticatory path of the incisor point was not related to the amount of lateral movement, but was closely and proportionally related to the amount of vertical movement.