Efficacy of Photobiomodulation Therapy Using 980nm Versus 635nm Diode Lasers for Treatment of Myofascial Pain

This randomized controlled clinical trial investigates the effectiveness of low-level laser therapy (LLLT) using two diode laser wavelengths-980 nm and 635 nm-for the treatment of myofascial pain syndrome (MPS) in patients with temporomandibular disorders (TMD). The study is conducted at the National Institute of Laser Enhanced Sciences (NILES), Cairo University. Participants who meet the inclusion criteria are randomly assigned to two intervention groups. Group 1 receives LLLT using a 635 nm diode laser, while Group 2 receives LLLT using a 980 nm diode laser. Both groups undergo treatment twice per week for a total of five weeks, following a standardized protocol. The primary outcomes include pain intensity assessed using a visual analog scale (VAS), and evaluation of mandibular range of motion including lateral and protrusive movements. Secondary outcomes involve the assessment of masseter and temporalis muscle activity using surface electromyography (sEMG) before and after the treatment period. The study aims to provide evidence-based comparison between the two wavelengths in terms of pain reduction and neuromuscular improvement, contributing to the optimization of non-invasive laser protocols for TMD-related myofascial pain.