The combination of ultrasound and muscular stretching may have positive effects on pain relief and on the balance of the masticatory muscles activity.

This study aimed to evaluate the therapeutic response of ultrasound (US) and ultrasound associated with stretching of the masticatory muscles on the pressure pain threshold and the electrical activity of masseter and anterior temporal muscles in Temporomandibular Disorder (TMD) patients . The study included 18 women with TMD diagnosed by the instrument Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD). The pressure pain threshold, evaluated through algometry, and the electrical activity of the masticatory muscles were evaluated, by means of surface electromyography, before and immediately after the therapeutic procedures. The volunteers underwent three different interventions: ultrasound, ultrasound associated with stretching and ultrasound placebo, with a 1-week of minimum interval between them.

Inclusion Criteria:

• diagnosis of myogenic or mixed TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC / TMD)
• women aged 20 to 35 years.

Exclusion Criteria:

• psychomotor impairment ;
• history of orthopedic trauma involving the temporomandibular region , orofacial surgery or poor training ;
• analgesics , anti-inflammatories , muscle relaxants , antidepressants ;
• presence of acute TMJ pain ( last 3 months) ;
• have perform physical therapy or speech therapy for the past 6 months;
• periods of the end of the menstrual cycle (7 days prior to menstruation ) and onset of menstruation ( first 2 days ) were excluded for conducting evaluations of volunteers who did not use oral contraception and those who used it to break.