Magister Scientiae Dentium - MSc(Dent) / The objective of the study was to compare pain and functional limitation of temporomandibular myalgia patients, before and after low-level-laser treatment (LLLT).This was a prospective, randomized, placebo-controlled, triple-blinded clinical study. Patients diagnosed with temporomandibular myalgia according to the DC/TMD protocol were recruited from the TMD clinic of the Mitchell’s Plain Oral Health Centre. Treatment was performed using diode laser (Sirolaser, Dentsply Sirona). The 3 regions of the masseter and temporalis muscles were treated bilaterally with a dose of 8J/cm2 per region. Pain and function were assessed using pain-free opening, numeric rating scales (NRS), Characteristic Pain Intensity Scores (CPIS), Interference Score (IS), and Jaw Functional Limitation Scale (JFLS) at the first and last LLLT and at 4-week recall (intervals 1, 2, 3). Statistical analysis was done by means of explorative categorical principal and multivariate interdependent analysis.