The Role of Injection of Botulinum Toxin in Lateral Pterygoid Muscle for Management of Temporomandibular Joint Disorders: A Systematic Review and Meta Analysis

This systematic review and meta analysis rigorously examines the effectiveness of botulinum toxin type A (BTX-A) injections into the lateral pterygoid (LP) muscle for treating temporomandibular disorders (TMDs).

Adhering to PRISMA guidelines, the review analyzes studies from 2000 to 2022, identified through various databases and manual searches. Following the PICO framework, the inclusion criteria focus on clinical trials investigating BTX-A injections in the LP muscle to manage TMDs symptoms. The Cochrane risk of bias tool assessed study quality.

Out of 124 reports, five studies with 117 participants met the criteria. Most trials reported symptom improvements, particularly in reducing pain and clicking sounds. However, discrepancies in study design, assessment methods, and participant characteristics led to moderate to high bias, resulting in an overall assessment of moderate to poor quality evidence. While results are promising, consensus on the therapeutic efficacy of BTX-A for TMDs is lacking due to inconsistencies among studies. The proposed mechanisms include chemical denervation and analgesic effects, but further research is necessary to determine optimal dosages and injection sites. Adverse effects were typically temporary and manageable, though considerations about the cost-effectiveness of BTX-A therapy compared to alternatives are needed.

BTX-A injections in the LP muscle show potential for alleviating TMDs symptoms, but rigorous randomized controlled trials with larger sample sizes and extended follow-up periods are necessary for definitive evidence. Patients should be aware of possible transient effects and the need for repeated injections, which may complement other treatments for improved outcomes.