What are the causes, diagnosis, and treatment options for sleep-related bruxism?

Sleep-Related Bruxism: Causes, Diagnosis, and Treatment

Sleep bruxism is primarily managed through protective oral appliances, behavioral strategies, and in some cases, pharmacological interventions, with treatment decisions based on the presence of symptoms and complications rather than the bruxism itself.

Causes of Sleep Bruxism

Sleep bruxism is now understood as a centrally controlled condition with multiple contributing factors rather than simply a dysfunctional movement or pathological condition:

• Sleep bruxism is characterized by repetitive jaw muscle activity involving teeth grinding or clenching during sleep 1
• The etiology is likely multifactorial and regulated centrally through pathophysiological and psychosocial factors rather than peripheral morphological factors 2
• Potential causes include:
  • Genetic predisposition 3
  • Stress and psychological factors 3
  • Central nervous system changes 3
  • It may serve a protective role during sleep, such as maintaining airway patency or stimulating saliva flow 1
• Sleep bruxism occurs in approximately 13% of adults 2

Diagnosis of Sleep Bruxism

Diagnosis involves a combination of approaches:

• Clinical evaluation is necessary to differentiate between awake bruxism and sleep bruxism 4
• Diagnostic methods include:
  • Patient reports and clinical interviews 1
  • Clinical examination for signs such as:
    • Masticatory muscle hypertrophy
    • Tooth surface loss
    • Fracture of restorations or teeth
    • Hypersensitive or painful teeth 1
  • Intraoral appliances to detect grinding patterns 1
  • Recording of muscle activity 1
• Polysomnography is generally only required when sleep comorbidities are present 4
• Ruling out secondary bruxism caused by medical disorders or medications is important 4

Treatment Approaches

General Principles

• Bruxism itself does not always require treatment; management is indicated only when problems arise as a result of bruxism 1
• No current treatment permanently "cures" or "stops" sleep bruxism 2
• Treatment goals include:
  • Protection of teeth and restorations
  • Reduction of bruxism activity
  • Pain relief 2

Oral Appliances

• Custom-made oral appliances are the most common intervention:
  • Primarily protect dentition from damage caused by clenching/grinding 1
  • May provide transient reduction in muscle activity 4
  • Effective for preventing dental damage and reducing grinding sounds 4
  • Occlusal splints should be fitted by qualified dental personnel trained in sleep medicine and/or sleep-related breathing disorders 5
  • Candidates for mandibular repositioning appliances require:
    • Adequate healthy teeth
    • No significant temporomandibular joint disorder
    • Adequate jaw range of motion
    • Manual dexterity to insert/remove the appliance 5

Behavioral Approaches

• First-line interventions include:
  • Sleep hygiene counseling 4
  • Sleep habit modification 4
  • Relaxation techniques 4
  • Biofeedback 1
• These approaches have low evidence of efficacy but are generally considered safe 4

Pharmacological Interventions

• Limited evidence supports pharmacological management:
  • Clonazepam has been reported to improve sleep bruxism in patients with psychiatric and sleep comorbidities, but insufficient evidence exists to recommend its general use 4
  • Botulinum toxin injections in masticatory muscles may be considered for severe cases:
    • Can decrease bruxism for 1-5 months
    • May improve pain and mandibular function
    • Particularly useful in severe secondary bruxism associated with neurological disorders 4

Contraindicated Approaches

• Irreversible occlusal adjustments have no evidence basis in the management of bruxism 1

Complications and Side Effects

• Potential complications of untreated bruxism include:

  • Temporomandibular disorders and pain 2
  • Headaches 2
  • Tooth wear, fracture, and hypersensitivity 1
  • Implant and restoration failure 2
  • Loss of periodontal support 1

• Side effects of oral appliance therapy may include:

  • Temporomandibular joint discomfort 5
  • Dental misalignment with long-term use 5
  • Hypersalivation or dry mouth 5
  • Dental pain and gingival irritation 5

Follow-up and Monitoring

• Regular dental follow-up is recommended to:
  • Assess effectiveness of interventions
  • Monitor for dental complications
  • Adjust treatment as needed 5
• For patients using oral appliances, follow-up should occur at 6 months for the first year and at least annually thereafter 5

Research Gaps

Current knowledge gaps include:

• Long-term studies comparing different therapeutic modalities 4
• Effects of treatments on bruxism EMG activity 4
• Progression of dental wear with different interventions 4
• Standardized outcomes for treatment of sleep bruxism 6