Abstract
For evaluation of stomatognathic function it is of great importance to investigate the spatial relationship between the mandibular condyle and the temporal-bone articular fossa (condylar position). The purpose of this study is to analyze the condylar position quantitatively not only at intercuspation but also during jaw movements. A three-dimensional reconstruction of the temporo mandibular joint (TMJ) is made by the corrected lateral tomography, which is coupled with the jaw movement data recorded by a jaw tracking device (MM-JI): and then the condylar movements with six degrees of freedom are described on the graphic terminal.
I examined changes of the bony joint spaces in 8 subjects (16 TMJs) at intercuspation and during sagittal and lateral border moN'rements. The results are as follows:
1. An analysis of the relationship between the position of the condyle and that of the kinematic condylar point (KCP) showed that 1) in case the KCP is located anterosuperior or superior to the condyle, the posterosuperior or the posterior portion of the condyle approaches the eminentia or the fossa in the maximal opening and the hinge movement during the sagittal border movement; and 2) in case the KCP is located medial to the condyle, the posterior portion of the working-side condyle approaches the fossa during the lateral movement.
2. The condylar position at intercuspation had influences on that during jaw movements.
