Abstract
Purpose: The present study reviewed information obtained by conventional methods for analyzing condylar movement, and investigated the merits of 4-dimensional analysis compared to conventionalmethods.
Methods: Numerous studies have already reported on conventional methods for volunteers orpatients. The aim of this study was to describe the characteristics of each method. A patient withtemporomandibular dysfunction was therefore selected as the subject of this study. Mandibularmovement was recorded using a 6-degree-of-freedom jaw-tracking device, and the incisal and condylarpoints and bilateral first molars were selected as points of analysis. The skull and mandible werereconstructed from a computed tomography (CT) dataset into 3-dimensional images, and mandibularmovement data were applied to these images (4-dimensional analysis).
Results and Discussion: Large amounts of information were obtainable by analyzing mandibularmovements using conventional methods. Stick figures comprising the occlusal plane connected tobilateral condylar points were useful for understanding mandibular movements as a whole. Inaddition, condylar movements on the working side that are actually very difficult to record wereclarified by describing the movements of anatomical condylar points. Relationships between anatomicalstructures and mandibular movements were elucidated using 4-dimensional analysis. This methodtherefore seems useful for diagnosing and treating patients with or without temporomandibulardisorders.
Conclusions: Conventional methods provide sufficient information to grasp the conditions of thetemporomandibular joint, but 4-dimensional analysis offers opportunities not available with othermethods.
