Effects of different energy density low-level laser therapies for temporomandibular joint disorders patients: a systematic review and network meta-analysis of parallel randomized controlled trials

Purpose To compare the effects of different energy density LLLT on TMD patients’ pain reduction. Methods Reviewers searched RCTs published in Embase, PubMed and The Cochrane Library before 1 April 2020. Reviewers included parallelRCTs that compared the effects of LLLT with placebo or different energy density LLLT for TMD patients’ pain reduction. Reviewers did network meta-analysis and evaluated the quality of evidence using the GRADE process. Results From 352 studies, reviewers included 16 RCTs. Immediately after treatment, the d1 laser therapy (energy density ranging from 0 to 10 J/cm 2 ) ranked first. The d1 laser therapy showed more pain reduction than placebo ( MD = 2.49, 95% CI ranging from 1.28 to 3.71). The quality of “d1 vs p” comparison was assessed as “moderate” quality. A month after treatment, the d1 laser therapy also performed better than placebo (MD = 1.69, 95%CI = [-0.78, 4.16]). The quality of secondary outcome was assessed as “low” quality. Conclusions For clinical application, d1 laser therapy (energy density ranging from 0 to 10 J/cm 2 ) is recommended for short-term pain management of TMD patients (moderate quality evidence). A month after treatment, the d1 laser therapy also performed better than placebo and other laser groups but the result didn’t reach the point of statistical significance (low quality evidence). Trial registration: PROSPERO-CRD42018118313.