Bruxism

Bruxism
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Synonyms	Teeth grinding, jaw clenching
Pronounce
Field	Dentistry
Symptoms	Tooth wear, jaw pain, headaches, sensitive teeth, TMJ pain, sleep disturbances
Complications	Tooth fracture, temporomandibular joint dysfunction, tooth loss, periodontal disease, myofascial pain
Onset	Can occur at any age; often starts in childhood or early adulthood
Duration	Chronic or episodic
Types	Awake bruxism, sleep bruxism
Causes	Stress, anxiety, sleep disorders, malocclusion, side effects of certain medications
Risks	Emotional stress, caffeine or alcohol use, certain drugs (e.g. SSRIs), poor sleep habits, family history
Diagnosis	Clinical evaluation, patient history, observation, sometimes polysomnography
Differential diagnosis	Temporomandibular joint dysfunction, tooth erosion, occlusal trauma, myofascial pain syndrome
Prevention	Stress management, good sleep hygiene, behavior modification, limiting stimulants
Treatment	Occlusal splints, behavioral therapy, stress reduction, medications (e.g., muscle relaxants, botulinum toxin)
Medication	Muscle relaxants, benzodiazepines, anxiolytics, botulinum toxin
Prognosis	Good with treatment, but may recur with stress or sleep disruption
Frequency	Affects 8–31% of the population; more common in children and young adults
Deaths	Rare; not typically fatal

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View from above of an anterior (front) tooth showing severe tooth wear exposing the dentin layer. The pulp chamber is visible.

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The left temporalis muscle

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The left medial pterygoid muscle and lateral pterygoid muscle

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The left masseter muscle in red

Bruxism is the excessive grinding of the teeth or clenching of the jaw, often an unconscious habit. It is classified as a parafunctional habit, meaning it serves no functional purpose such as eating or speaking. Bruxism can occur while awake (awake bruxism) or during sleep (sleep bruxism).

Types of Bruxism

Bruxism is typically divided into two categories:

• Sleep bruxism – occurs during sleep and is considered a sleep-related movement disorder.
• Awake bruxism – occurs during wakefulness, often in response to stress or anxiety.

Causes

The exact causes of bruxism are not fully understood, but several contributing factors may include:

• Stress, anxiety, and emotional disturbances
• Malocclusion (misalignment of the teeth)
• Sleep disorders such as sleep apnea
• Certain medications (e.g., some antidepressants)
• Neurodevelopmental disorders (e.g., ADHD)
• Substance use (e.g., caffeine, alcohol, tobacco, recreational drugs)

Signs and Symptoms

Common signs and symptoms of bruxism include:

• Excessive tooth wear, especially attrition on the occlusal (biting) surfaces
• Tooth sensitivity due to worn enamel and exposed dentin
• Headaches, particularly in the temporal region
• Pain or tenderness in the TMJ and Muscles of mastication
• Tooth fractures or damage to dental restorations
• Trismus (limited mouth opening)
• Audible grinding or clenching sounds during sleep (reported by a partner)
• Scalloped tongue or linea alba on the inner cheeks due to cheek biting
• Enlargement (hypertrophy) of the masseter muscle

Tooth Wear and Damage

Tooth wear from bruxism often appears as:

• Attrition – enamel loss from tooth-to-tooth contact
• Abfraction – wedge-shaped defects at the gumline
• Cracks and tooth fractures
• Compromised dental crowns, fillings, and veneers

Diagnosis

Bruxism is diagnosed based on:

• Clinical examination of tooth wear and jaw muscle tension
• Patient-reported symptoms such as jaw pain or morning headaches
• Observation by a partner (especially for sleep bruxism)
• Use of polysomnography in complex or uncertain cases

Complications

Untreated bruxism can lead to:

• Damage to teeth and dental restorations
• Temporomandibular joint dysfunction
• Periodontal disease aggravation
• Myofascial pain syndrome
• Sleep disturbances

Treatment

While there is no single cure, treatments focus on symptom management and preventing further damage.

Dental Interventions

• Occlusal splints (night guards): Custom devices that protect teeth from grinding forces.
• Occlusal adjustment: Selective reshaping of tooth surfaces to balance the bite (used cautiously).
• Restorative dentistry: Repairing damaged teeth with crowns or other restorations.

Behavioral Therapy

• Stress management techniques such as biofeedback, cognitive behavioral therapy (CBT), meditation, and relaxation therapy
• Sleep hygiene improvements to reduce nighttime grinding
• Awareness training to reduce daytime clenching

Medications

• Muscle relaxants before bedtime (short-term use)
• Anxiolytics (for stress-related bruxism)
• Adjustment of antidepressants if they contribute to bruxism
• Botulinum toxin (Botox) injections in severe cases to reduce muscle activity

Prognosis

The prognosis varies. Many individuals experience improvement with stress management and dental protection. In children, sleep bruxism often resolves without treatment.

See also

• Temporomandibular joint dysfunction
• Tooth wear
• Sleep disorders
• Occlusal trauma
• Dentistry
• Muscles of mastication