The aim of this review was  to  assess the scientific evidence on the efficacy of low-level laser therapy (LLLT) in the treatment of temporomandibular disorders (TMD). The authors searched  the  PubMed, Science Direct, Cochrane Clinical Trials Register, and PEDro databases.  Papers were screened, extracted, and quality assessed  independently by two  reviewers.

A meta-analysis- was performed to quantify the pooled effect of LLLT on pain and function in patients with chronic TMD. The primary outcome of interest was the change in pain from baseline to endpoint.

From the 323 papers found  by the search strategy  they identified six randomized clinical trials (RCT) met the inclusion criteria.

The found that:-

• The pooled effect of LLLT on pain, measured through a visual analog scale with a mean difference of 7.77 mm (95% confidence interval [CI]: -2.49 to 18.02), was not statistically significant from placebo.
• Change from baseline to endpoint of secondary outcomes was
• 4.04 mm (95% CI 3.06 to 5.02) for mandibular maximum vertical opening;
• 1.64 mm (95% CI 0.10 to 3.17) for right lateral excursion and
• 1.90 mm (95% CI: -4.08 to 7.88) for left lateral excursion.

The authors concluded

Currently, there is no evidence to support the effectiveness of LLLT in the treatment of TMD.

Petrucci A, Sgolastra F, Gatto R, Mattei A, Monaco A. Effectiveness of low-level laser therapy in temporomandibular disorders: a systematic review and meta-analysis. J Orofac Pain. 2011 Fall;25(4):298-307.