Abstract
For clarifying the function of occlusion and obtaining better structure of articulator, I measured three-dimensional mandibular movements in lateral excursions starting from the intercuspal position, by a method which regards the mandible as a rigid body.
Firstly, I showed some characteristcs of the paths of some representative jaw points, such as incisor, first molar, and both side condyles, and Compared them with formerly reported data.
Secondly, I analyzed immediate movements which are now considered to be very important. By analyzing movements of the incisal point and the working condyle simultaneously, I found a rapid motion of the working condyle occuring in a initial phase during which the incisal point traveled a distance of merely 0.5mm.
As average moved distance of the working condyle in this phase was 0.19mm which was too small as compared with the immediate side shift, these motions seemed to occur in free way space of the condylar stable position. The influence of initial rapid motions of the working condyle on tooth's paths, however, couldn't be recognized.
