Trajectories of condylar points during nonworking side and protrusive movements of the mandible

Statement of problem. During lateral excursive and protrusive jaw movements , condylar points are distant from any instantaneous rotational center. The refore, it is likely that different condylar paints would follow similar tr ajectories during these movements. Purpose. This study evaluated the effect of changes in condylar point locat ion on trajectories of condylar points on the nonworking side and during a protrusive jaw movement and compared these changes with the effects describ ed for open-close and working-side condylar movements in the same group of subjects. Methods. The movements of 5 clinically determined condylar paints were reco rded in 44 subjects during a contralateral excursion and during protrusion (7 radiographically determined condylar points in 2 subjects). Results. During any single jaw movement, the trajectory of each condylar po int was similar in form and dimension to the other condylar points within t hat subject. Conclusion. Changes in condylar point location had little effect on the tra jectories of condylar points on the nonworking side and during protrusive j aw movement.