Onabotulinum toxin-A injections for sleep bruxism: A double-blind, placebo-controlled study

OBJECTIVESTo test the safety and efficacy of onabotulinum toxin-A (BoNT-A) injections into the masseter and temporalis muscles in patients with symptomatic sleep bruxism. METHODSParticipants 18 to 85 years old with clinically diagnosed sleep bruxism confirmed by polysomnography were enrolled in this randomized, placebo-controlled, 1:1, parallel-design trial with open-label extension. Participants were injected with BoNT-A 200 units (60 into each masseter and 40 into each temporalis) or placebo and were evaluated at 4 to 8 weeks after the initial treatment visit. The primary efficacy endpoint was clinical global impression (CGI), and the secondary efficacy endpoint was a visual analog scale (VAS) of change in bruxism and in pain at 4 to 8 weeks after injection. Exploratory endpoints included modified Montreal Bruxism Questionnaire, Headache Impact Test-6, total Pittsburgh Sleep Quality Index, Epworth Sleepiness Scale, Self-Rated Anxiety Scale, and polysomnography data, including EMG recordings of the masseter and temporalis muscle bruxing events. Adverse events were recorded. RESULTSThirty-one participants were recruited and 23 were randomized (19 female, age 47.4 ± 16.9 years). All 13 randomized to BoNT-A and 9 of 10 randomized to placebo completed the study. CGI (p < 0.05) and VAS of change (p < 0.05) favored the BoNT-A group. None of the exploratory endpoints changed significantly, but total sleep time and number/duration of bruxing episodes favored the BoNT-A group. Two participants randomized to BoNT-A reported a cosmetic change in their smile. No dysphagia or masticatory adverse events were reported. CONCLUSIONSBoNT-A effectively and safely improved sleep bruxism in this placebo-controlled pilot trial. A large multicenter trial is needed to confirm these encouraging data. CLINICALTRIALS.GOV IDENTIFIERNTC00908050. CLASS OF EVIDENCEThis study provides Class II evidence that botulinum injections into the masseter and temporalis muscles improve subjective bruxism and painful symptoms associated with sleep bruxism.