Ultrasonography as a tool for evaluating treatment of the masseter muscle in temporomandibular disorder patients with myofascial pain

Objectives This study clarified ultrasonography (US) changes after splint therapy and investigated the use of this modality for evaluating treatment of the masseter muscle in temporomandibular disorder (TMD) patients with myofascial pain. Methods Twenty-five female TMD patients with myofascial pain were examined with US before and after splint therapy. The thickness and internal appearance of the masseter muscle were evaluated. Results No differences in thickness were found before and after treatment in either “Improved” or “Not improved” patients. Twelve patients showed changes in the internal appearance. A significant difference was observed in the distributions of types of internal appearance before and after treatment. Three representative cases are presented. Conclusions US has potential for evaluating the masseter muscle in TMD patients with myofascial pain, especially muscles that appear edematous before treatment.