Biomechanics and Motion Analysis

Temporomandibular Joint Kinematics

Principal Investigator: Eugene E. Keller, D.D.S.
Project Coordinator: Kristin Zhao — zhao.kristin@mayo.edu

We have developed a technique for recording the kinematics of the temporomandibular joint and incisors, using an electromagnetic tracking device and custom dental appliances. Subjects' mandibular motion during maximal opening tasks were recorded on two different days and linear distance (LD) (i.e., the linear distance between the start and end position) and curvilinear path (CP) (i.e., the curvilinear distance along the curve between the start and end position) were calculated for the lower incisor landmark and both condyles in the sagittal plane (in mm). Fourteen healthy subjects participated in this kinematic study (11 females, 3 males, mean age of 31.4 years) of mandibular motion. Subjects were asked to perform the following maximal movements: opening-closing, protrusive-retrusive, and (right and left) lateral. The mean linear distance (LD) and curvilinear path (CP) values for the mandibular incisal and condylar movements during open-closing, protrusive and lateral movements in the sagittal plane were in the normal range compared to previous literature. The mean mandibular incisal and condylar deviation in the frontal plane during the opening and protrusive movements were also comparable to previous literature values. The results of this study suggest that it will be possible to use this methodology in future studies to detect significant differences between healthy subjects and patients with TMJ implants. This technique is unique in that it is portable, unencumbering to the patient, yet sufficiently accurate and repeatable in quantifying differences between normal joint motion and that of TMJ patients.