Optimum ultrasonic therapy of the masseter muscle for temporomandibular disorders

Abstract

I investigated the optimum ultrasonic therapy of the masseter muscle for temporomandibular disorders (TMD). The deep temperatures of the bilateral masseter muscles and the forehead were measured non-invasively at rest and after ultrasonic therapy in 14 normal male subjects. The right masseter muscle of each subject was exposed to a continuous sonic wave of 3 MHz, at an intensity of 0.5, 0.75, and 1.0 W/cm² for 5 and 10 minutes. The subjects were asked about pain during and after the ultrasonic therapy. The deep temperature was calculated at rest, and at 20 and 60 minutes after ultrasonic therapy (ΔT), and the ascending rate (AR) and descending rate (DR) were calculated from the deep temperature under each condition. The ΔT and AR for 10 minutes were significantly higher than for 5 minutes. The DR for 1.0 W/cm² was significantly higher than for 0.5 W/cm^2. No subject experienced pain at the intensity of 0.5 W/cm² during or after ultrasonic therapy. These findings suggest there is an optimum ultrasonic therapy of the masseter muscle for TMD.