Hamid Reza Khalighi
Hamed Mortazavi
Seyed Masoud Mojahedi
Saranaz Azari Marhabi
Faranak Moradi Abbasabadi

Abstract Introduction: Temporomandibular disorders (TMD) lead to masticatory muscle pain, jaw movement disability and limitation in mouth opening. Pain is the chief complaint in ۹۰% of the TMD patients which leads to disability and severe socioeconomic costs. The purpose of this study was to evaluate the therapeutic effects of low level laser therapy (LLLT) compared to pharmacotherapy with NSAIDs (naproxen) in myofascial pain disorder syndrome (MPDS).Methods: In this randomized controlled clinical trial, ۴۰ MPDS patients were divided into two groups. One group received naproxen ۵۰۰ mg bid for ۳ weeks as treatment modality and also had placebo laser sessions. The other group received active laser (diode ۸۱۰ nm CW) as treatment and placebo drug. Pain intensity was measured by visual analogue scale (VAS) and maximum painless mouth opening was also measured as a functional index every session and at ۲ months follow up. Data was collected and analyzed with SPSS software. Independent t test was used to analyze the data. A P < ۰.۰۵ was considered significant.Results: Low level laser caused significant reduction in pain intensity (P < ۰.۰۵) and a significant increase in mouth opening. In naproxen group neither pain intensity nor maximum mouth opening had significant improvement. Pain relief, in subjective VAS was observed in third session in LLLT group, but did not occur in naproxen group. Maximum mouth opening increased significantly in laser group compared to the naproxen group from the eighth session.Conclusion: Treatment with LLLT caused a significant improvement in mouth opening and pain intensity in patients with MPDS. Similar improvement was not observed in naproxen group. Keywords: Myofascial pain disorder syndrome Laser therapy Low-level Naproxen Temporomandibular