The hierarchy of different treatments for myogenous temporomandibular disorders: a systematic review and network meta-analysis of randomized clinical trials

The best treatment modality for the management of painful temporomandibular disorders of muscular origin (M-TMD) with predictable outcomes based on solid evidence is still not well defined. Thus, the aim of this network meta-analysis (NMA) was to identify the best treatment for adult patients with M-TMD. An electronic search was undertaken from the inception of each database to August 2018, to identify randomized clinical trials (RCTs), which are comparing two or more of the following treatment modalities in patients with M-TMD: counseling therapy; occlusal appliances; manual therapy; laser therapy; dry needling; intramuscular injection of local anesthesia (LA) or botulinum toxin-A (BTX-A); muscle relaxants; hypnosis/relaxation therapy; oxidative ozone therapy; and placebo or no treatment. Primary outcome variables were the reduction of pain and mechanical sensitivity. The secondary outcome was the maximal mouth opening (MMO). The quality of evidence was rated according to Cochrane's tool for assessing risk of bias. Standardized mean difference was used to analyze via frequentist network meta-analysis (NMA), using STATA software. 52 RCTs were included in this NMA. At the most follow up moments, manual therapy, counseling therapy, occlusal splints therapy, and needling using BTX-A or LA as well as dry needling significantly decreased post-treatment pain intensity in M-TMDs, when compared to placebo.  At short term (≤5 months), the four highest-ranked treatments for post-treatment pain reduction were manual therapy (83.5%, low quality evidence), ozone therapy (75.7%, very low quality evidence),counseling  therapy (71.2%, moderate quality), and occlusal appliances  (71.7%,moderate quality evidence). When intermediate term (≥6 months)was considered, BTX-A (85.8%, very low quality evidence) , counseling therapy(80%, low quality evidence), occlusal appliances  (62.8%, low quality evidence) and hypnosis (50.6%, very low quality evidence) were the four highest-ranked treatments.  This NMA reveals that manual therapy can be considered the most effective treatment for M-TMD, followed by counseling treatment, intramuscular injection of LA, and occlusal appliances  . However, considering the limitations of the studies included, and the scarce of strong evidence, the present findings should be interpreted cautiously.