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Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Botulinum toxin for nocturnal bruxism.
Scientific title
Efficacy of Botulinum Toxin Type A in the Targeted Treatment of Nocturnal Bruxism: A Double-Blind, Randomised, Placebo-Controlled Cross-over Study
Secondary ID [1] 293593 0
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Bruxism 305847 0
Condition category
Condition code
Neurological 305056 305056 0 0
Other neurological disorders
Oral and Gastrointestinal 305057 305057 0 0
Other diseases of the mouth, teeth, oesophagus, digestive system including liver and colon

Study type
Description of intervention(s) / exposure
The intervention is a set of injections at 2 time points, at least 20 weeks apart, performed by a trained neurologist at Royal Melbourne Hospital. The treatment consists of intramuscular injections of Botox (onabotulinumtoxinA) (dose range of 90-120units as detailed below) and 0.9% normal saline (dose range 1.8ml-2.4ml), in a randomised, double blind, cross-over study.

The doses detailed are based on the minimally clinically effective doses within the range of those used in published studies.

Patients will be randomised to receive injections into:
A. Masseter muscles bilaterally (30 units or 0.6ml normal saline each side);
B. Masseter and temporalis muscles bilaterally (30 units/15 units each muscle respectively, or 0.6ml/0.3ml respectively); or
C. Masseter, temporalis and medial pterygoid muscles bilaterally (30units/15units/15 units each muscle respectively, or 0.6ml/0.3ml/0.3ml normal saline respectively).

The duration of treatment effect for botulinum toxin injected into the face, head and neck area has been observed to be approximately 3-4 months. Therefore a 20-week (5month) washout period was chosen to ensure that there is no remaining active treatment effect before the cross-over set of injections.

At 20 weeks, there will therefore be a single set of injections, of either active treatment or placebo, in the same sites as the first injection, again performed by a trained Neurologist at Royal Melbourne Hospital.

Study investigators will contact the participants to arrange followup within 7 days of the specified timepoint, for clinical assessment and outcome measures. Participants will also be given dates for followup in advance of the scheduled timepoints to ensure fidelity to the intervention followup schedule.
Intervention code [1] 299847 0
Treatment: Drugs
Comparator / control treatment
Placebo (0.9% normal saline, 1.8-2.4ml)
Control group

Primary outcome [1] 304222 0
Composite primary outcome: change in bruxism severity (objectively measured by overnight surface EMG, validated questionaires addressing bruxism (Bruxism symptom questionnaire), headache (headache impact test (HIT-6) questionnaire, pain (modified Short-Form McGill pain scale) and sleepiness severity (using the Epworth sleepiness scale), following injection of onabotulinum toxin and placebo.
Timepoint [1] 304222 0
4 weeks following injection of onabotulinum toxin or placebo.
Primary outcome [2] 304223 0
Safety of botulinum toxin in the treatment of nocturnal bruxism as measured by clinical review. A neurologist will be clinically assessing the participant, discussing any change in health or possible side-effects of the treatment and documenting details.

The possible expected side effects are bruising/discomfort and rarely excessive muscle weakness (manifest as weakness with chewing).
Timepoint [2] 304223 0
4 weeks following injection of onabotulinum toxin or placebo
Secondary outcome [1] 351141 0
Duration of benefit following Botulinum toxin injection on symptoms of Bruxism.
Timepoint [1] 351141 0
Weeks 4, 12, 20 following injection of either placebo or Botulinum toxin

Key inclusion criteria
Symptoms of nocturnal bruxism of adequate severity as measured by overnight monitoring.
Minimum age
18 Years
Maximum age
No limit
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Contraindication to botulinum toxin administration, concurrent use of medications affecting muscle relaxation, prior history of severe jaw trauma, orofacial pain of an alternate aetiology, neuromuscular disease, major respiratory disease(s) that may preclude overnight EMG recordings, administration of botulinum toxin for other indication (including cosmetic) within 16weeks of study commencement.

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?
The people receiving the treatment/s
The people administering the treatment/s
The people assessing the outcomes
The people analysing the results/data
Intervention assignment
Other design features
Phase 2
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment in Australia
Recruitment state(s)
Recruitment hospital [1] 9542 0
Royal Melbourne Hospital - City campus - Parkville
Recruitment postcode(s) [1] 18296 0
3050 - Parkville

Funding & Sponsors
Funding source category [1] 298210 0
Name [1] 298210 0
Melbourne Health
Address [1] 298210 0
Royal Melbourne Hospital
Grattan Street,
Parkville, VIC 3050
Country [1] 298210 0
Primary sponsor type
Melbourne Health
Royal Melbourne Hospital
Grattan Street,
Parkville, VIC 3050
Secondary sponsor category [1] 297313 0
Name [1] 297313 0
Address [1] 297313 0
Country [1] 297313 0

Ethics approval
Ethics application status
Ethics committee name [1] 299217 0
Melbourne Health Human Research Ethics Committee
Ethics committee address [1] 299217 0
Grattan St,
VIC 3050
Ethics committee country [1] 299217 0
Date submitted for ethics approval [1] 299217 0
Approval date [1] 299217 0
Ethics approval number [1] 299217 0

Brief summary
Bruxism is a diurnal or nocturnal involuntary repetitive oral activity consisting of a non-functional rhythmic (or spasmodic) grinding, clenching or gnashing movement of the teeth. The diagnosis of bruxism is made by reports of tooth grinding/clenching during sleep, and one of either: abnormal tooth wear, sounds associated with bruxism, and/or jaw muscle discomfort. In adults, the prevalence of sleep bruxism is reported to be around 6% for the grinding type and 20% for the clenching type. Sleep bruxism has been linked to a variety of headache syndromes including temporomandibular disorders and chronic migraine.

The ultimate goal of this research is to develop a more effective therapeutic intervention for bruxism sufferers with the use of BTA injection. Patients will mainly be recruited via the Botulinum Toxin Clinic at Royal Melbourne Hospital, as well as via referrals from dental orofacial pain specialists and neurologists. The study is a randomized, double blind, placebo-controlled trial with a crossover design; the study duration is 40weeks from the time of randomisation. All participants meeting eligibility criteria will be required to consent to approved study protocols.
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 79694 0
A/Prof Lynette Kiers
Address 79694 0
4N Neurophysiology
Royal Melbourne Hospital
Grattan Street
VIC 3050
Country 79694 0
Phone 79694 0
+61 03 93427693
Fax 79694 0
+61 03 93424085
Email 79694 0
Contact person for public queries
Name 79695 0
Dr Belinda Cruse
Address 79695 0
4N Neurophysiology
Royal Melbourne Hospital
Grattan Street
VIC 3050
Country 79695 0
Phone 79695 0
+61 03 93427693
Fax 79695 0
+61 03 93424085
Email 79695 0
Contact person for scientific queries
Name 79696 0
Dr Belinda Cruse
Address 79696 0
4N Neurophysiology
Royal Melbourne Hospital
Grattan Street
VIC 3050
Country 79696 0
Phone 79696 0
+61 03 93427693
Fax 79696 0
+61 03 93424085
Email 79696 0

No data has been provided for results reporting
Summary results
Not applicable