EFFECT OF ANTERIOR REPOSITIONING SPLINTS ON THE ELECTROMYOGRAPHIC ACTIVITIES OF MASSETER AND ANTERIOR TEMPORALIS MUSCLES

The effect of anterior repositioning (AR) splint therapy on masticator y muscle activity was investigated in seventeen patients with internal derangement; disk displacement with reduction in particular, Integrat ed electromyography (EMG) recordings from the masseter and anterior te mporalis muscles were analyzed quantitatively during maximal biting in intercuspal position before and after eight week treatment period. EM G recordings were taken for each subject prior to the beginning of cli nical therapy and final EMG recordings were made without AR splint to provide a standard for comparison. The results of the investigation re vealed the following: 1. AR splint therapy did not cause any significa nt modification of the EMG activity in the recorded muscles during max imal biting in intercuspal position; 2. Before and after treatment the EMG activity from the masseter muscle was less than from the temporal muscle; 3. AR splint therapy resulted in reduction of the pain (88.2% ) and jaw joint sounds (64.7%) and mean vertical opening which was 42. 17mm before treatment increased to 45.06mm.