Bruxism: Are botulinum toxin injections effective in management?


Bruxism is a repetitive muscular activity involving the clenching or grinding of teeth that can occur during wakefulness or sleep. Bruxism may result in muscle pain, tooth wear, fractures and damage to restorations.  A range of management approaches have used alone or in combination. These include oral appliances, electrical stimulation, counselling/ behavioural strategies and centrally acting drugs, with a common target being muscle relaxation. Positive outcomes with botulinum toxin injections have been reported in patients with bruxism since the 1990s.

The aim of this review is to assess the clinical outcomes of the use of botulinum toxin type A injections in the management of primary bruxism in adults.


The review protocol was registered in the PROSPERO database and conducted in line with PRISMA. Searches were conducted in the PubMed/Medline, Cochrane CENTRAL, Scopus, LILACS, Web of Science and system for Information on Grey Literature in Europe (SIGLE) databases.  Clinical studies reporting on the effects of botulinum toxin for the management of bruxism were considered. Two reviewers independently conducted the search and selected studies. Three reviewers extracted data with two reviewers independently assessing study quality using the Fowkes and Fulton checklist. Because of study heterogeneity a narrative summary was presented.


  • 10 studies (6 randomised controlled trials [RCTs] and 4 case series) involving a total of 237 patients were included.
  • 6 studies were considered to have a low risk of bias 3 a moderate risk and one a high risk.
  • Sample sizes ranged from 8-120 patients
  • 4 different brand of botulinum toxin were used
  • Different toxin concentration, dosage schedules and follow up periods were employed between studies as were clinical evaluation methods.
  • All the included studies reported a benefit from botulinum toxin.


The authors concluded: –

Botulinum toxin type A injections are effective in the treatment of the symptoms of primary bruxism in adults. Randomized clinical trials are still needed to establish a protocol for using botulinum toxin as an alternative to traditional therapies in the management of primary bruxism.


The authors have registered their protocol and conducted a good search of a wide range of databases for this review. However, only a limited number of small studies are available to address this question.    We have previously looked at a review by De la Torre Canales et al of this topic (Dental Elf – 31st Mar 2017). That review included just 5 studies, all of which are included in this new review. Of the 5 new studies included in this new review 3 are RCTs and all are relatively small with only one having a sample size of 50 patients. The fact that only 60% of the new studies are small RCTs when there is a clear need to well conducted studies to provide evidence for the management of bruxism is disappointing.

In addition to the small sizes of the included studies there was considerable variation in the brand, concentration, dosage regime and protocols for the intervention. This heterogeneity meant that meta-analysis was not possible.  So, while there is some indication that botulinum toxin injections may have some efficacy in treating bruxism high quality, well-conducted and reported RCTs of appropriate size and duration need to be conducted to provide good quality evidence. In addition to determining effectiveness different dosage regimes need to be tested and agreement reached on reporting common outcomes including adverse events.


Primary Paper

Sendra LA, Montez C, Vianna KC, Barboza EP. Clinical outcomes of botulinum toxin type A injections in the management of primary bruxism in adults: A systematic review. J Prosthet Dent. 2020 Jul 19:S0022-3913(20)30359-0. doi: 10.1016/j.prosdent.2020.06.002. Epub ahead of print. PMID: 32698998.

Review protocol on PROSPERO

Other references

Dental Elf – 31st Mar 2017

Bruxism: Are botulinum toxin injections helpful?

Dental Elf – 21st Mar 2012

Botulinum toxin for bruxism





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