Non-Cochrane · intervention · PM42795952
Effects of Botulinum Toxin Injection on Masticatory Muscle Activity in Sleep Bruxism: A Systematic Review and Meta-Analysis.
Val Matteo, Colonna Anna, Nykänen Laura, et al. · Journal of clinical medicine · 2026 · PubMed · doi:10.3390/jcm15187179
Findings
19 findings
| Population | ||||
|---|---|---|---|---|
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG-based muscle activity, frequency and amplitude Fixed-effect sensitivity analysis | Hedges g -0.84 [-1.13, -0.54] GRADE not reported 5 studies · 101 participants |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Fixed-effect sensitivity; assumed correlation r=0.3; paired Cruse and change-score Ondo | Hedges g -0.570 [-0.943, -0.198] GRADE not reported 3 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Fixed-effect sensitivity; assumed correlation r=0.9; paired Cruse and change-score Ondo | Hedges g -1.157 [-1.579, -0.735] GRADE not reported 3 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG-based muscle activity, frequency and amplitude Random-effects leave-one-out; excluding Lee et al. 2010 | Hedges g -0.92 GRADE not reported 4 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG-based muscle activity, frequency and amplitude Primary post-treatment time points, typically 2–4 weeks · Overall; random effects | Hedges g -1.09 [-1.65, -0.54] Low Downgraded: risk of bias, inconsistency 5 studies · 101 participants |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Fixed-effect sensitivity; assumed correlation r=0.7; paired Cruse and change-score Ondo | Hedges g -0.772 [-1.157, -0.386] GRADE not reported 3 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG signal amplitude Construct subgroup; fixed effect | Hedges g -1.31 [-1.95, -0.68] Low Downgraded: risk of bias, inconsistency 2 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Construct subgroup; fixed effect | Hedges g -0.70 [-1.04, -0.37] Low Downgraded: risk of bias, inconsistency 3 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | Questionnaire, clinical global impression and PSG bruxism frequency | No consistent BoNT-A-specific benefit on subjectively/frequency-assessed bruxism Very low Downgraded: risk of bias, imprecision, inconsistency 5 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Fixed-effect sensitivity; assumed correlation r=0.5; paired Cruse and change-score Ondo | Hedges g -0.642 [-1.019, -0.266] GRADE not reported 3 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | Short-term adverse events 2 weeks to 6 months | Mild, transient adverse effects reported in 3/5 RCTs; no serious adverse events in any trial Low Downgraded: imprecision, indirectness 5 studies · 101 participants |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG-based muscle activity, frequency and amplitude Random-effects leave-one-out; excluding Cruse et al. 2022 | Hedges g -1.34 GRADE not reported 4 studies |
| Adults with sleep bruxism | Botulinum toxin type A injection into masticatory muscles | Placebo injection | EMG bruxism event frequency Fixed-effect sensitivity; assumed correlation r=0.0; paired Cruse and change-score Ondo | Hedges g -0.504 [-0.874, -0.135] GRADE not reported 3 studies |
| Adults with sleep bruxism | BoNT-A injection into masseter and lateral pterygoid | BoNT-A injection into masseter only | Masseter EMG amplitude 2 weeks | no estimate extracted GRADE not reported 1 study · 30 participants |
| Adults with sleep bruxism | BoNT-A injection into masseter and lateral pterygoid | BoNT-A injection into masseter only | Lateral pterygoid EMG amplitude 2 weeks | no estimate extracted GRADE not reported 1 study · 30 participants |
| Adults with sleep bruxism | BoNT-A injection into masseter and temporalis | BoNT-A injection into masseter only | EMG peak amplitude | no estimate extracted GRADE not reported 1 study · 20 participants |
| Adults with sleep and/or awake bruxism | BoNT-A injection into masseter | Before treatment, same participants | Masseter EMG amplitude 2 months | SMD (pre-post Cohen d) -1.51 GRADE not reported 1 study · 304 participants |
| Adults with sleep bruxism | BoNT-A injection into masseter with or without lateral pterygoid | Before treatment, same participants | Masseter EMG amplitude 2 weeks | SMD (pre-post Cohen d) -2.77 GRADE not reported 1 study · 30 participants |
| Adults with sleep or awake bruxism | Botulinum toxin type A injection into masticatory muscles | No treatment or untreated control | Bruxism or masticatory muscle activity | no estimate extracted No studies found 0 studies |
Included primary studies 12
Open in Studies| Study | Year | Also included by | Outcomes it informs here | Trial data |
|---|---|---|---|---|
| Alzaeem 2025 Comparative effectiveness of injecting botulinum toxin type A in the masseter muscle with or without injection in the lateral pterygoid… DOI:10.1016/j.jormas.2025.102404 | 2025 | this review only | not stated | not extracted yet |
| Alzaeem 2025 Comparative effectiveness of injecting botulinum toxin type A in the masseter muscle with or without injection in the lateral pterygoid… PMID:40350077 | 2025 | this review only | not stated | not extracted yet |
| Cruse 2022 Efficacy of botulinum toxin type a in the targeted treatment of sleep bruxism: a double-blind, randomised, placebo-controlled, cross-over… DOI:10.1136/bmjno-2022-000328 | 2022 | this review only | EMG-based muscle activity, frequency and amplitude | not extracted yet |
| Cruse 2022 Efficacy of botulinum toxin type a in the targeted treatment of sleep bruxism: a double-blind, randomised, placebo-controlled, cross-over… PMID:36110927 | 2022 | this review only | not stated | not extracted yet |
| Furuhata 2025 Factors Influencing the Effectiveness of Botulinum Toxin Therapy in Bruxism Management. PMID:40864060 | 2025 | this review only | not stated | not extracted yet |
| Lee 2010 Effect of Botulinum Toxin Injection on Nocturnal Bruxism DOI:10.1097/phm.0b013e3181bc0c78 | 2010 | this review only | EMG-based muscle activity, frequency and amplitude | not extracted yet |
| Lee 2010 Effect of botulinum toxin injection on nocturnal bruxism: a randomized controlled trial. PMID:19855255 | 2010 | this review only | not stated | not extracted yet |
| Ondo 2018 Onabotulinum toxin-A injections for sleep bruxism DOI:10.1212/wnl.0000000000004951 | 2018 | this review only | EMG-based muscle activity, frequency and amplitude | not extracted yet |
| Ondo 2018 Onabotulinum toxin-A injections for sleep bruxism: A double-blind, placebo-controlled study. PMID:29343468 | 2018 | this review only | not stated | not extracted yet |
| Shehri 2022 Evaluation of the Efficacy of Low-Dose Botulinum Toxin Injection Into the Masseter Muscle for the Treatment of Nocturnal Bruxism: A… PMID:36474649 | 2022 | this review only | EMG-based muscle activity, frequency and amplitude | not extracted yet |
| Shim 2014 Effects of botulinum toxin on jaw motor events during sleep in sleep bruxism patients: a polysomnographic evaluation. PMID:24634627 | 2014 | this review only | not stated | not extracted yet |
| Shim 2020 Botulinum Toxin Therapy for Managing Sleep Bruxism: A Randomized and Placebo-Controlled Trial. PMID:32182879 | 2020 | this review only | EMG-based muscle activity, frequency and amplitude | not extracted yet |
Review question
| Element | Planned (methods) | Found (results) |
|---|---|---|
| Population | Adults (18 years or older) diagnosed with sleep or awake bruxism (possible, probable or definite) | Adults with sleep bruxism (n=8 studies; 455 participants); awake bruxism only indirectly captured |
| Intervention | BoNT-A injection into masticatory muscles (masseter, temporalis, medial or lateral pterygoid) | BoNT-A into masseter, with or without temporalis, medial or lateral pterygoid (n=8) |
| Comparison | Placebo (saline) injection, no treatment/untreated arm, other conservative management, or active comparator (different BoNT-A protocol, muscle combination or dose) | Placebo (n=5 RCTs, 101 participants); alternative BoNT-A protocol (n=2 RCTs); no control (n=1 observational) |
| Outcomes | Bruxism/masticatory muscle activity (EMG amplitude, EMG-derived events or Bruxism Index, PSG-scored RMMA, validated bruxism-frequency questionnaires or clinical global impression); adverse effects as safety outcome | EMG-based muscle activity (n=8; pooled n=5); questionnaire/CGI/PSG-frequency bruxism measures (n=6, narrative); adverse events (n=8) |
| Study designs | RCTs (placebo-controlled or active-comparator) or prospective observational studies | Placebo-controlled RCTs (n=5, incl. 1 crossover); active-comparator RCTs (n=2); prospective single-arm observational study (n=1) |
| Timing | Studies published January 2005 to July 2026 | Follow-up 2 weeks to 6 months |
AMSTAR 2 items
Two independent extractors rated each item. Their ratings are shown side by side because they have not been reconciled yet. The overall rating follows Shea et al. 2017: one critical flaw gives Low, more than one gives Critically Low.
| Item | Extractor A | Extractor B | Agree |
|---|---|---|---|
| 1Research question includes PICO components | Yes | Yes | yes |
| 2Protocol established before the reviewcritical | Partial Yes | Partial Yes | yes |
| 3Choice of study designs explained | No | No | yes |
| 4Comprehensive literature searchcritical | No | Partial Yes | no |
| 5Study selection in duplicate | Yes | Yes | yes |
| 6Data extraction in duplicate | Yes | Yes | yes |
| 7List of excluded studies with reasonscritical | No | No | yes |
| 8Included studies described in detail | Partial Yes | Yes | no |
| 9Risk of bias assessed satisfactorilycritical | RCT: Yes · NRSI: Partial Yes | NRSI: No · RCT: Yes | no |
| 10Funding of included studies reported | No | No | yes |
| 11Appropriate meta-analysis methodscritical | RCT: Yes · NRSI: N/A | NRSI: N/A · RCT: Yes | no |
| 12Impact of risk of bias on the pooled results | No | No | yes |
| 13Risk of bias accounted for in interpretationcritical | Yes | Yes | yes |
| 14Heterogeneity explained | Yes | Yes | yes |
| 15Publication bias investigatedcritical | No | No | yes |
| 16Conflicts of interest reported | Yes | Yes | yes |
| Overall | Critically Low | Critically Low | yes |