Non-pharmacological interventions for temporomandibular disorders: A systematic review and meta-analysis

Background

A temporomandibular disorders (TMDs) is a musculoskeletal and neuromuscular condition that affects the temporomandibular joint, masticatory muscles, and associated tissues. Non-pharmacological interventions are currently considered as potential therapies for TMDs. However, high-quality systematic reviews and meta-analyses evaluating their clinical efficacy are lacking.

Objective

This study aimed to evaluate the clinical efficacy of non-pharmacological interventions for TMDs, focusing on their impact on pain relief, jaw mobility, and functional improvement. Specifically, we aimed to compare the effectiveness of four non-pharmacological interventions, including acupuncture, exercise, occlusal splinting, and laser therapy, for treating TMDs.

Methods

Comprehensive searches for randomized controlled trials (RCTs) were conducted in PubMed, Web of Science, Scopus, Embase, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure, China Biomedical Literature Database (SinoMed), VIP, and Wanfang databases. The primary outcome was visual analog scale (VAS) score. The secondary outcomes included pain-free mouth opening, maximum assisted and unassisted mouth opening, and occurrence of adverse events. We used the Cochrane Risk of Bias tool and the Grading of Recommendations Assessment, Development, and Evaluation approach to assess the risk of bias and the quality of evidence. The meta-analysis was performed using RevMan 5.4 software.

Results

A total of 22 RCTs involving 717 patients with TMDs were included. Non-pharmacological interventions significantly reduced VAS scores (n=19; mean difference [MD]= –1.86, 95 % confidence interval [CI] –2.40 to –1.31; Z=6.68; P<0.05) and improved the pain-free mouth opening (n=6; MD=6.92, 95 % CI 4.91 to 8.94; Z=6.73; P<0.05) and maximum unassisted mouth opening (n=10; MD=4.05, 95 % CI 2.08 to 6.02; Z=4.04; P<0.05) in patients with TMDs. However, non-pharmacological interventions did not show a significant effect on maximum assisted mouth opening (n=2; MD=0.33, 95 % CI –4.16 to 4.82; Z=0.15; P=0.88). Only one RCT reported the occurrence of adverse events. Subgroup analysis showed that acupuncture (n=6; MD= –1.52, 95 % CI –2.86 to –0.18; Z=2.22; P=0.03), exercise (n=4; MD= –1.12, 95 % CI –1.94 to –0.31, Z=2.70; P<0.05), occlusal splint (n=5; MD= –2.00, 95 % CI –2.67 to –1.33, Z=5.88; P<0.05), and laser therapy (n=4; MD= –2.81, 95 % CI –3.89 to –1.73, Z=5.10, P<0.05) were significantly superior to control treatments in reducing VAS scores. In addition, acupuncture (n=2; MD=6.50, 95 % CI 3.87 to 9.13; Z=4.85; P<0.05), occlusal splint (n=2; MD=8.33, 95 % CI 4.41 to 12.24; Z=4.17; P<0.05), and laser therapy (n=2; MD=6.09, 95 % CI 0.86 to 11.32; Z=2.28; P=0.02) significantly improved pain-free mouth opening, whereas exercise (n=2; MD=6.84, 95 % CI 3.16 to 10.51; Z=3.65; P<0.05) and occlusal splint (n=2; MD=4.93, 95 % CI 1.66 to 8.19; Z=2.96; P<0.05) increased maximum unassisted mouth opening.

Conclusion

Nonpharmacological interventions have significant efficacy in relieving pain and enhancing pain-free mouth opening and maximum unassisted mouth opening in patients with TMDs. Specifically, acupuncture, exercise, occlusal splinting, and laser therapy significantly alleviate pain in patients with TMDs. Occlusal splinting showed good effects in improving pain-free mouth opening and maximum unassisted mouth opening, while acupuncture and laser therapy helped improve pain-free mouth opening. Exercise significantly improved maximum unassisted mouth opening. These findings support the application of these treatments in clinical practice and provide evidence to inform future conservative management guidelines for TMDs.