Is acupuncture an effective treatment for temporomandibular disorder? A systematic review and meta-analysis of randomized controlled trials

Background: Acupuncture is used for treating various disorders, but its effects on temporomandibular disorder (TMD) remain unclear. This study aimed to assess the effectiveness and safety of acupuncture for TMD via a systematic review of randomized clinical trials. Methods: A total of 11 Korean and worldwide databases were searched to identify acupuncture studies in adults with TMD. A Cochrane risk of bias assessment was performed on all articles; a meta-analysis, which involved the categorization according to the type of control used (inactive control, active control, or add-on), was subsequently performed. The quality of evidence was assessed using the Grading of Recommendations, Assessment, Development and Evaluation methodology. Results: The qualitative analysis of randomized clinical trials with acupuncture as the intervention included 32 articles, 22 of which were included in the quantitative analysis (471 participants). Acupuncture significantly improved outcomes (effect rate, relative risk [RR]: 7.00, 95% confidence interval [CI]: 1.91, 25, 62; visual analog scale, standardized mean difference: 0.49, 95% CI: 0.24, 0.73) versus active controls (effect rate, RR: 1.19; 95% CI: 1.12, 1.27). In the analysis of add-ons, acupuncture significantly improved the effect rate and pain intensity (effect rate, RR: 1.36; 95% CI: 1.04, 1.77; visual analog scale, mean difference: -1.23; 95% CI -1.79, -0.67). However, the quality of evidence was determined to range from low to very low. Conclusion: Acupuncture in TMD significantly improved outcomes versus active controls and when add-on treatments were applied. However, as the quality of evidence was determined to be low, well-designed clinical trials should be conducted in the future.