The Movement of the Chin during Mastication

Abstract

The purpose of this study was to evaluate suitability of the soft tissue on the chin as a reference point in measuring masticatory movements. The movements of the chin and a lower incisor during mastication were measured simultaneously using a real-time measuring system for three-dimensional movements of soft tissues (3-D Auto Tracking System).
The results were as follows
1. Computer-based analysis was developed to divide the whole-chewing period into single stroke and determine the beginning of the opening, closing, occluding phase.
2. The chin movements were 1/60 sec slower than lower incisor movements at the beginning of the opening phase.
3. The chin movements were 1/60 sec faster than lower incisor movements at the beginning of the occluding phase.
The results obtained in this study indicate that the soft tissue on the chin was suitable as a reference point in measuring masticatory movements.