Efficacy of initial conservative treatment options for temporomandibular disorders: A network meta-analysis of randomized clinical trials

Purpose: This network meta-analysis (NMA) of randomized controlled trials (RCTs) aimed to identify effective initial conservative treatment strategies for patients with temporomandibular joint disorders (TMD). Study selection: RCTs comparing treatment options for TMD published between January 2000 and July 2021 were retrieved from the databases of PubMed and Embase via a comprehensive electronic search. Patients diagnosed with myalgia (muscle pain) or arthralgia (joint pain) according to pain-related Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) and the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) were eligible for inclusion. Twelve treatment options and a placebo were included in the mutual comparisons. The risk of bias was assessed using Risk of Bias 2.0. Forest plots of direct comparisons between individual studies were created using MetaInsight. NMA was performed using R statistical software (netmeta). Results: Twenty-four RCTs involving 1336 patients assessing pain and 12 RCTs involving 614 patients assessing maximal mouth opening were identified. Low-level laser therapy (standard mean difference [SMD]:-2.12, 95% confidence interval [CI]:-3.18, -1.06), self-exercise (SMD:-1.51, 95% CI:-2.82,-0.2), and stabilization splints (SMD:-1.16, 95% CI:-2.02,-0.29) were effective in improving pain; however, the certainty of evidence was very low. Self-exercise (SMD: 0.71, 95% CI:-0.58, 2.01), stabilization splints (SMD: 0.65, 95% CI:-0.09, 1.39), and low-level laser therapy (SMD: 0.63, 95% CI:-0.34, 1.6) were effective in improving maximal mouth opening; however, the certainty of evidence was very low. Conclusions: Stabilization splints, self-exercise, and low-level laser therapy may be effective in the initial treatment of TMD.