A new method for recording temporomandibular joint sounds and electrical jaw muscle activity in relation to jaw opening degree

Abstract

A system for continuously quantifying of jaw movements in terms of jaw angle was tested in combination with a previously tried method for simultaneous recording of temporomandibular joint (TMJ) sounds and electromyographic (EMG) activity. The system was used to measure the degree of rotation of the lower jaw in the sagittal plane in relation to the upper jaw. It was tested on a group of healthy subjects and patients with TMJ clicking and found useful to record EMG activity and TMJ clicking in relation to opening degree and velocity of jaw movement in open-close cycles.