RESUMO
OBJECTIVE: To investigate ultrasonographic changes of masseter muscle (MM) in patients with myofascial pain disorder (MPD) and possible correlations with clinical features. METHODS: The study included 20 MPD patients and 20 healthy volunteers. Masseter muscle thickness (MMT) and the echogenic pattern were ultrasonographically evaluated. The maximum interincisal opening (MIO), duration of symptoms, and pain level were evaluated for correlations with MMT. RESULTS: At relaxation, MMT was greater in the test group (p < 0.05); however, the percentage of increase in MMT from relaxation to contraction was greater in controls (p < 0.05). In MPD patients, the echogenic pattern differed significantly from controls. In MPD patients, a strong positive correlation was found between MMT and pain level, while a moderate negative correlation was found between MMT and both the duration of symptoms and MIO. CONCLUSION: Ultrasound is an adjunctive method for complementing the assessment of the MM condition in MPD patients.
