Use of botulinum neurotoxin Type A in the management of primary bruxism in adults: An updated systematic review.

Statement Of Problem: The psycho-emotional effects caused by the coronavirus pandemic have increased the intensity and number of cases of bruxism, for which no treatment has been considered fully effective. Botulinum neurotoxin Type A (BoNT-A) has shown positive results as an adjunct treatment of primary bruxism; however, this off-label use does not have an established protocol, and further studies are required.

Purpose: The purpose of this updated systematic review was to analyze the clinical outcomes of BoNT-A in the management of primary bruxism in adults.

Material And Methods: The review was registered under the International Prospective Register of Systematic Reviews (PROSPERO) registration number CRD42021287653, without funding. PubMed, Web of Science, Scopus, LILACS, Cochrane Library, and Open Grey Literature databases were searched by using the Mendeley Desktop software program without language restrictions up to June 6, 2021. The risk of bias of the selected randomized clinical trials was assessed by using RoB2, and the level of evidence was measured by 2 independent researchers using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) tool.

Results: A total of 741 references were obtained from the 6 databases in this systematic review. The 11 randomized clinical trials selected achieved a reduction in bruxism symptoms by injecting BoNT-A into 211 participants with different protocols. The heterogeneity of the included studies did not permit a meta-analysis.

Conclusions: All the evaluated studies supported the effectiveness of BoNT-A injections in reducing bruxism symptoms. The reduction of symptoms can be obtained with doses lower than 25U applied exclusively in the masseter muscles.