A system for the study of jaw movements.

This paper describes a system to record incisal and condylar movements. It consists of two Charge Coupled Device (CCD) cameras that detect the position of markers fixed to the face, real-time hardware to recognize the markers and software for three-dimensional reconstruction of condylar and mandibular movements. The subject sat upright in front of the cameras and was asked to perform jaw movements. The position of the markers was recorded and the coordinates were fed into the computer and converted to three-dimensional kinematic data by a mathematical algorithm implemented on an AT IBM personal computer. Dedicated software calculated the head movements and the mandibular movements separately and performed a three-dimensional mathematical reconstruction of the movements of the condylar points and the interincisive point, using the geometrical rules of a rigid body. This pilot study describes the pattern from opening, closing, protrusive, and lateral movements as obtained from healthy subjects with good dentition.