Photobiomodulation in the Treatment of Temporomandibular Disorders: A Systematic Review

Abstract Purpose of Review Temporomandibular disorders (TMD) are common causes of orofacial pain and may substantially impair mandibular function and quality of life. Photobiomodulation (PBM), delivered using laser or light-emitting diode (LED) devices, has emerged as a non-invasive therapeutic option, but uncertainty remains regarding its specific clinical effects and optimal treatment parameters. This systematic review evaluated the efficacy, safety, methodological quality, and certainty of evidence for PBM in adults with TMD. Recent Findings This systematic review followed PRISMA 2020 guidelines and was registered in PROSPERO (CRD420251140804). PubMed, Embase, Scopus, LILACS via BVS, and MEDLINE via BVS were searched for randomized controlled trials published within the prespecified period from January 2015 to September 2025. Fourteen RCTs, comprising 1,001 randomized participants, were included. PBM protocols were highly heterogeneous, with wavelengths ranging approximately from 630 to 905 nm and treatment regimens ranging from a single session to 14 applications. Several trials demonstrated greater reductions in pain with active PBM than with sham or comparator interventions; however, treatment effects were inconsistent across TMD subtypes and protocols, and substantial improvements were also observed in placebo and active-control groups. Functional outcomes, including mandibular mobility and patient-reported function, generally showed favorable but heterogeneous findings. Evidence for oral-health-related quality of life was limited. Five of the 14 included trials (35.7%; 492 randomized participants) reported adverse-event information in some form. No serious adverse events were reported in these studies, although harm ascertainment was incomplete and nonstandardized. Risk-of-bias concerns were present in several trials. Comparison-specific GRADE certainty ranged from moderate to very low and was generally low or very low. Summary PBM may provide short-term benefits for pain and function in TMD, but the magnitude and durability of its specific therapeutic effect remain uncertain. Standardized protocols, adequately powered sham-controlled trials, consistent outcome measures, systematic adverse-event monitoring, and longer follow-up are needed to strengthen clinical recommendations.