Background and Objective: Myofascial pain syndrome (MPS) is characterized by trigger points affecting more than one muscle group and pain associated with muscle spasm and tenderness caused by touching these points. The etiology of myofascial pain syndrome is still not fully identified. Factors such as genetic factors, bruxism, stress, occupational factors, lassitude and especially chronic injuries caused by recurrent micro traumas can cause myofascial pain syndrome. The first choice of MPS treatment is conservative treatment. The purpose of this study was to evaluate of effect of low level laser therapy treatments (LLLT) clinically and thermographically in patients with myofascial pain syndrome.

Methods: Ten female patients with myofascial pain syndrome were involved into this study. Patients were examined by clinically and Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) was used for the diagnosis of TMS. 970 nm diode laser were used for low level laser therapy. Laser application areas were extraorally temporal muscle, masseter muscle, sternocleidomastoid muscle and retromandibular region and intraorally the point where inferior lateral pterygoid muscles attached with fovea pterygoidea selected.  0.5 Watt laser energy was applied with a biostimulation probe as a total of 5 joules for 10 seconds as each zone separately. A total of 10 sessions of DDLT procedure were performed on every other day.

Results: After low level laser therapy treatments, a significant decrease were found in superficial skin temperature on both sides of masseter muscle.

Conclusion: The present findings show that low level laser therapy reduce the superficial skin temperature over masseter muscle and thermography can be a useful imaging device to diagnose on myofascial pain syndrome.