Correlation of splint therapy outcome with the electromyography of masticatory muscles in temporomandibular disorder with myofascial pain

Objectives. The aim of this study was to assess the effect of occlusal splint therapy on the electromyographic amplitude records (mu V) of masticatory muscles in temporomandibular disorder (TMD) with myofascial pain and to detect a possible existence of a relationship between this effect and the treatment outcome. Materials and methods. Forty patients (23 females and 17 males) having TMD with myofascial pain were included in this study. They were randomly divided into two equal groups (20 of each). The first group (A) was treated by occlusal splints for 6 months while the second group (B) acted as a control. A clinical assessment and surface electromyography (EMG) for the masticatory muscles were performed at the beginning of the study, then 6 months later. The collected data were statistically analyzed using paired t-test. The differences were considered significant at p < 0.05. Results. The results showed that 85% of group A either completely recovered (35%) or clinically improved (50%) while only 20% of group B had a spontaneous improvement. In group A, the means of the electromyographic amplitude records (mV) of the monitored muscles have decreased after 6 months. However, the decrease was statistically insignificant (p > 0.05) in the patients (15%) who had no clinical changes. In group B, the means of the muscles' records (mV) in the left side slightly increased while those of the right side slightly decreased. These changes were statistically insignificant (p > 0.05). Conclusions. Occlusal splint could eliminate or improve the signs and symptoms of TMD patients with myofascial pain. It reduces the electromyographic amplitude records (mV) of the masticatory muscles. The splint therapy outcome has a correlation with the electromyographic amplitude changes of the masticatory muscles.