抄録
To understand the relationship between disc displacement status and condylar movement, the mandibular movement together with articular disc position of 80 outpatients with temporomandibular disorders were examined. Articular disc position was detected with a 1.5 T MR scanner. Mandibular movement was analyzed with a six-degree-of-freedom jaw tracking device.
Evaluation of nonworking condylar movement during lateral excursion jaw movement made it possible to reduce the effect of contralateral condylar movement.
The results were as follows:
1. Out of 160 mandibular joints, 80 joints were found to be disc displaced. Thirty-nine cases involved reduction and 41 nonreduction.
2. No joint having disc displacement with reduction was classified as grade 3, implying the most prominent displacement in terms of condylar head and disc positional relationship.
3. It showed a high correlation between the range of condylar movement and that of incisal movement regardless of the disc situation.
4. Range of lateral movement at the nonworking condylar point was influenced by the degree of displacement rather than by the instance or lack of reduction.
