Background and Aim: One of the most common causes of facial pain, is muscular pain. MPDS is one of the most important disorders of facial area that many of patients suffer from pain, tenderness of one or more masticatory muscles and limitation of movement. Psychological factors play an important role in MPDS. Anxiety and depression by increasing muscle tension, can cause myofacial pain syndrome; They can also accompany the syndrome as comorbidities or develop as sequelae of chronic pain and disability. Many approaches can be used to treat myofacial pain syndrome. The least invasive and least traumatic approach should be se.lected. Often, treatment for myofacial pain syndrome fails, because underlying problems go untreated. Progressive Muscle Relaxation (PMR) is mainly used for treating anxiety and depression. The aim of this study was to evaluate the effect of PMR in improving signs and symptoms of patients with MPDS.

Materials and Methods: In this before and after clinical trial study, 33 patients with MPDS that had anxiety and or mild depression(were assessed by Beck Inventory)were treated by PMR in a period of a month (3 visits)and were followed up until 2 months. Analysis was done using paired t-test/ wilcoxon-sign-rank test.

Results: The results of this study showed that variants like intensity of pain, tenderness of masticatory muscles, maximum opening of mouth with and without pain, anxiety (p<0.001) and depression (p=0.001) improved significant 16 after treatment in comparison with before treatment.

Conclusion: In conclusion, PMR is effective in improving signs and symptoms in patients with MPDS. Therefore psychological status should be considered in treatment plan of these patients.