Botulinum Toxin for Bruxism: An Overview.

This overview aimed at assessing botulinum toxin type A (BoNT-A)'s effectiveness in managing bruxism compared to a placebo, the absence of treatment, or other interventions in adults. Only systematic reviews (SRs), with or without a meta-analysis, were included. A comprehensive literature search was conducted on 16 June 2024, encompassing seven databases and grey literature sources. Experts and reference lists of the included SRs were also consulted. Study selection was conducted in two phases by two independent authors. Methodological quality was evaluated using AMSTAR-2. Overlap was assessed using the corrected covered area. The 14 included SRs addressed several outcomes. In most studies, BoNT-A showed effectiveness in reducing pain ( = 10), the frequency of bruxism events ( = 7), and the maximum bite force ( = 5). None of the SRs effectively evaluated BoNT-A's impact on functional movements. All of the included SRs scored "critically low" and "low" confidence rates in AMSTAR-2. Only one SR attempted to assess the certainty of the evidence, although unsuccessfully. The overlap across included SRs was rated as "high", with a corrected covered area of 10.11%. The current systematic reviews on BoNT-A for bruxism lack methodological quality, limiting the reliability of their findings. Despite evidence indicating a potential reduction in pain, bruxism events, and the maximum bite force, methodological limitations prevent definitive conclusions from being drawn. High-quality research with standardized methodologies is essential to establish BoNT-A's efficacy and support evidence-based clinical practice.