抄録
A computerized analysis system for the masticatory muscles has been developed. Silent period (SP), which observed in masticatory muscles shortly after the tooth contact during tapping movements or after chin tap during clenching, has been determined of its diagnostic value for TMJ dysfunction.
This system has the following characteristics; 1) applicable for a dental clinic, 2) automated objective measurements of the SP parameters, and 3) easy data processing for statistical analyses.
In order to measure the SP parameters, threshold level technique and peak to peak technique are common. However, since these techniques have some disadvantages, a new technique, “activity changing curve” has been developed. This parameter is independent of the amplitude of the EMG and shows marked increase at the onset or the termination of the SP. Thus it indicates the SP parameters more clearly and more objectively than the other methods.
We are proposing a four muscles and four divisions coordination pattern analysis, which shows a status of the masticatory function by means of durations and integrated values of the masticatory muscles and a stochastic analysis, which shows constitution of the SP by means and standard deviations of the EMG signal at each time.
As the results of this systematic analyses for clinical examination of many subjects, the patients with TMJ dysfunction showed significantly variation of SP duration etc. This clinical application has proved the efficiency of this system.
