Sleep Bruxism (Nocturnal Teeth Grinding)

What Is It?

• More than 85% of people may brux at some point; clinically significant in ~5%
• Occurs in any sleep stage but most common at the N1/N2 transition, stage 2 NREM, and REM sleep
• Grinding during REM sleep is more commonly associated with dental wear and damage
• Patients are usually unaware of the problem - often diagnosed during a dental visit

Causes and Risk Factors

Psychological / Behavioral

• Stress and anxiety - the most common precipitating factor; bruxism worsens during high-stress periods
• Heightened emotional arousal or distress
• Type A personality traits

Sleep-Related Causes

• Obstructive sleep apnea (OSA) - one of the strongest associated conditions; treating OSA alone may reduce bruxism episodes
• Restless leg syndrome and periodic limb movements during sleep
• REM sleep behavior disorder
• Sleep-related epilepsy
• Sleep-related gastroesophageal reflux (acid stimulation can trigger bruxing)

Substances and Medications

• SSRIs (antidepressants) - a well-recognized cause of both sleep and awake bruxism
• Psychostimulants - amphetamines, cocaine, ecstasy (MDMA)
• Heavy alcohol use
• Excessive caffeine consumption
• Tobacco use
• Dopaminergic medications and anxiolytics

Neurological and Psychiatric Disorders

• Parkinson's disease, Huntington's disease, multiple system atrophy
• Alzheimer's disease, traumatic brain injury
• Cerebral palsy, intellectual disability, Down syndrome, Rett syndrome, ADHD (and stimulants used to treat ADHD may partly drive the association)
• Oromandibular dystonia

Genetic Predisposition

• Occasional familial cases have been described; genetic factors are recognized contributors

Clinical Consequences

• Tooth wear, fractures, and damage to dental restorations
• Morning jaw pain or fatigue
• Temporal headaches (tension-type)
• Temporomandibular joint (TMJ) syndrome
• Restricted TMJ motion
• Loud grinding sounds that disturb the bed partner

Diagnosis

• Primarily clinical - based on history (patient, bed partner, or dental examination)
• Polysomnography (PSG) is the gold standard but mainly used when a concurrent sleep disorder (OSA) is suspected; shows characteristic EEG-EMG pattern with rhythmic jaw muscle activity
• Severity is judged by degree of sleep disruption, pain, and dental damage
• Note: bruxism is often less frequent in the lab setting (first-night effect), so repeat studies may be needed

Management

1. Occlusal Appliances (Mouth Guards / Night Guards)

• First-line mechanical treatment - custom-fitted occlusal splints worn during sleep
• Protect teeth from wear and reduce TMJ loading
• Do not cure bruxism but prevent dental damage

2. Treat Underlying Causes

• OSA: Positive airway pressure (CPAP) therapy - treating OSA alone often reduces bruxism frequency
• Medication-induced bruxism: Withdraw or substitute the offending drug (e.g., switch SSRI, reduce stimulant dose)
• Substance use: Counseling; reduce alcohol, caffeine, tobacco
• GERD: Appropriate acid suppression therapy

3. Behavioral and Psychological Interventions

• Cognitive behavioral therapy (CBT) - effective when stress/anxiety is the driver
• Biofeedback - helps patients become aware of and reduce jaw muscle tension
• Stress management and relaxation therapy - progressive muscle relaxation, mindfulness
• Exercise and habit modification
• In a 2024 study, patients undergoing combined cognitive and physical therapy reported a ~42% reduction in headache frequency from bruxism

4. Pharmacological Therapy

• Benzodiazepines (e.g., clonazepam) - useful short-term for stress-related bruxism; risk of dependence and falls
• Clonidine and propranolol (sympatholytic agents) - studied in randomized controlled trials with some benefit
• Dopamine agonists (bromocriptine) - reported benefit in case studies
• Note: No pharmacological agent has strong long-term evidence; pharmacotherapy is generally adjunctive

5. Botulinum Toxin (Botox) Injections

• Injections into the masseter muscles reduce bite force and grinding episodes
• Particularly useful in:
  • Neurogenic bruxism (Parkinson's disease, dystonia, Huntington's)
  • Severe cases unresponsive to other treatment
  • Autism spectrum disorder
• Evidence shows improvement in sleep time and frequency/duration of bruxing episodes

6. Children and Adolescents

• Per the IAPD 2024 consensus, there is currently insufficient evidence to support pharmacological management of sleep bruxism in children; behavioral approaches and reassurance are preferred

Summary Table