A recent review (Dental Elf – 3third February 2021) estimated that the prevalence of temporomandibular disorders (TMD) is 29.3% (95% CI: 6.1-72.3%), although the confidence intervals are very wide. Typical TMDs are treated conservatively with interventions including physical therapy (ultrasound, ultrashort wave, laser, heat, electrostimulation, relaxation exercises, active exercises, stretching, and biofeedback); use of a splint or brace; and pharmacological therapy. Surgical approaches such as arthrocentesis or arthroscopy can be used when these approaches are ineffective, and several studies have shown that acupuncture for TMD has shown high levels of patient satisfaction.
The objective of this review was to evaluate the effectiveness and safety of acupuncture in the treatment of temporomandibular joint (TMD) disorders.
Methods
A protocol was registered in the PROSPERO database. We searched Medline, Embase, Cochrane CENTRAL, China National Knowledge Infrastructure, NII Japanese citation information, Korea Med, Korean Medical Database; Integrated Advanced Search System for Oriental Medicine; National Discovery for Scientific Leaders; and Korean Studies Information Service System. We included randomized controlled trials (RCTs) that used acupuncture as an intervention for TMD in adults. Interventions considered included acupuncture, electroacupuncture, dry needling (DN), hot needle acupuncture, traditional acupuncture (KM acupuncture points), and contemporary acupuncture (A-shi points and trigger points). No treatment acupuncture and sham acupuncture were considered inactive controls, while active controls included physical therapy, injection therapy, splinting, and drug therapy including analgesia. Studies that did not use an objective assessment tool or those whose reliability and validity had not been established were excluded. Two reviewers independently selected studies, extracted data, and assessed risk of bias using the Cochrane tool (RoB2). Continuous variables were evaluated using mean difference (MD) or standardized MD (SMD) with 95% confidence intervals (CI) and dichotomous variables as relative risk (RR) with 95% CI. The certainty of the evidence was assessed by classification of recommendations, assessment, development and evaluation (QUALIFICATION) getting closer.
Results
- 32 RCTs met the inclusion criteria.
- Nine studies were from China, five from Brazil, four from Spain, three from Turkey and the United States, two from Austria, Sweden and the United Kingdom, and one each from Japan and Poland.
- None of the included studies had a low risk of bias, two had a high risk and all other studies demonstrated some concerns.
- Sample sizes ranged from 12 to 240 patients.
- 22 studies contributed to the meta-analysis.
Acupuncture versus inactive control.
- Meta-analysis (nine RCTs, 283 patients) showed that TMD pain assessed by VAS was significantly improved with acupuncture, SMD = 0.49 (95% CI: 0.24 to 0.73).
- Meta-analysis (5 RCTs, 152 patients) indicated that acupuncture significantly improved maximum mouth opening (MMO) compared to inactive control, MD = 4.18 (95% CI 2.87 to 5.48).
- Only one small study with 30 patients evaluated the effect rate of acupuncture in the treatment of TMD, suggesting a benefit of acupuncture, RR = 7.00 (95% CI: 1.91 to 25.62) .
Acupuncture versus active control treatment
- The meta-analysis (3 RCTs, 133 patients) found no difference between acupuncture and active treatments, MD = −0.41 (95% CI −0.91 to 0.10).
- Only 1 study (40 patients) evaluated MMO and found no significant difference between the acupuncture and active control groups, MD = 1.05 (95% CI −2.36 to 4.46).
- Meta-analysis (nine RCTs, 746 patients) showed that acupuncture significantly affected the effect rate, RR = 1.19 (95% CI: 1.12 to 1.27).
- The GRADE certainty of the evidence was rated from very low to low.
Conclusions
The authors concluded: –
It was difficult to reach a definitive conclusion about the effectiveness of acupuncture in the treatment of TMD because the studies included in the analysis were determined to contain low-quality data. Therefore, large-scale, well-designed RCTs are warranted in the future.
Comments
The authors previously registered this review in the PROSPERO database, although its original title was broader and sought to consider the use of Korean medical treatments for TMD, including herbal medicine, acupuncture, chuna, pharmacopuncture, etc. The published review focuses solely on acupuncture. A broad search was conducted in 11 databases and 32 RCTs ultimately met the inclusion criteria. We have previously discussed a review of acupuncture for TMD (Dental Elf – 28th June 2011) which included seven RCTs. Analyzes of acupuncture versus inactive controls (16 RCTs) and acupuncture versus active controls (19 RCTs) were performed and some studies included active and inactive controls. The included studies were very heterogeneous due to the various types of acupuncture use and the variation in the type of control used; There were also difficulties regarding blinding. Although the findings indicated a benefit from acupuncture, the quality of the studies was limited, so the certainty of the evidence was rated from very low to low. Consequently, the findings should be interpreted with caution and future studies should be well designed, reported, and appropriately sized.
Links
Primary job
Park EY, Cho JH, Lee SH, Kim KW, Ha IH, Lee YJ. YoIs acupuncture an effective treatment for temporomandibular disorder?: A systematic review and meta-analysis of randomized controlled trials. Medicine (Baltimore). September 22, 2023; 102 (38): e34950. doi: 10.1097/MD.0000000000034950. PMID: 37746950; PMCID: PMC10519525.
other references
Dental Elf – 3third February 2021
Prevalence of temporomandibular joint disorders
Dental Elf – 28th June 2011
Limited evidence on acupuncture as a symptomatic treatment of TMD
