Four-dimensional analyzing system of the stomatognathic function

—Application to the patients with jaw deformities—

Abstract

We introduce a new method of four-dimensional display of mandibular movement using the 3D-CT images of the skull and mandible, the dental surface image using a non-contact 3-D laser scanner and the mandibular movement data using a six-degree-of freedom-jaw movement analyzer. This method was employed to perform dynamic and precise simulation of the mandibular function for a patient with jaw deformity.
The advantages of this system were as follows:
1. The lento-skeletal 3D image and the mandibular movement data were integrated on the same coordinates on a personal computer. The mandibular movement of multiple required points on the integrated images was displayed by the computer graphics, which make it possible clearly to grasp a relationship between the motion pattern of the mandibular movement, skeletal morphology and occlusion simultaneously.
2. This new method of analyzing the occlusal contacts and the condyle-fossa distance provides the comprehensive insight of the stomatognathic system not only at intercuspal position, but also at any mandibular positions during functional movement.
3. Our system to evaluate the intersection between morphology and function will certainly improve our understanding of the function of the temporpmandibular joint and occlusion. We believe that it is useful for diagnosing the temporomandibular disorders to patients with jaw deformities.