THE TEMPORAL MASSETER COCONTRACTION - AN ELECTROMYOGRAPHIC AND CLINICAL-EVALUATION OF SHORT-TERM STABILIZATION SPLINT THERAPY IN MYOGENOUS CMD PATIENTS/

The short-term effect (3-6 weeks) of the use of a stabilization splint was investigated in a group of 35 myogenous craniomandibular disorder patients. The patients were clinically examined and surface EMG recor dings of the temporal and masseter muscles were made during clenching in the intercuspal position (ICP), immediately after the insertion of the splint (SSP), and after at least 3 weeks of splint treatment (SSP 3). With the use of the error variance of the activity index changes i n EMG activity were investigated. Three groups of patients were then r ecognized. One group showed a decrease in temporal muscle activity dur ing splint treatment. Another group did not show any significant chang e during splint treatment. The third group showed an increase of tempo ral muscle activity. In general, significant reductions in the amount of static pain were found. In the group with a significant reduction o f temporal muscle activity (n = 15) there was a greater decrease in th e amount of static pain (P < 0.05) than in the group (n = 4) with a si gnificant increase of temporal muscle activity. The results may indica te that the temporal muscle plays an important role in the perception of static pain in the masticatory system.