What Is Bruxism

Overview

Bruxism refers to the involuntary habit of grinding or clenching your teeth unconsciously, often throughout the day (awake bruxism) or while you are asleep (sleep bruxism). Factors like daily stress, posture, and sleeping habits can cause people to clench and grind their teeth. In the following article we will explain what bruxism is, the types of bruxism, possible causes, symptoms, and how it can be managed and treated.

What is bruxism?

Bruxism is defined as an involuntary movement disorder characterised by the excessive grinding or clenching of teeth.¹ This can occur while awake, but also during sleep. The two are considered as distinct conditions, but between them, awake bruxism is the more common one.²

In healthy individuals, bruxism can be considered as a muscle behaviour, which can either be harmless, or represent a risk factor for clinical consequences.

Bruxism can be categorized into two types:

• Primary: This type is not related to any other medical conditions.

• Secondary: This is associated with neurological disorders or as an adverse effect of certain medications.³

Sleep and awake bruxism are classified as two separate entities, although their physical motions are similar. Awake bruxism involves masticatory (chewing) muscle activity, where repetitive or sustained tooth contact occurs during wakefulness.⁴

Sleep bruxism also involves masticatory muscle activity, it happens during sleep and is characterised as either rhythmic or non-rhythmic.⁴ Clenching is usually more severe during sleep, as people can clench down with a force of up to 250 pounds since there is no active protective feedback mechanism to prevent it from happening.⁵

Possible causes

Although the exact cause of bruxism is not yet clear, several factors can contribute to its development. It is also worth noting that bruxism can be a risk factor for other health issues.

The prevalence of bruxism decreases with increasing age, and is more common in children and young adults.⁶ People may also experience bruxism and not suffer from any consequential symptoms. The factors that can influence whether or not bruxism causes pain will vary from person to person. 

These factors include:

1. Stress: higher stress levels or elevated anxiety can trigger bruxism.
2. Posture: posture can influence teeth grinding.
3. Sleeping habits: poor sleep quality and habits can impact sleep bruxism. This includes snoring, insomnia and obstructive sleep apnea.
4. Diet: certain dietary factors, including alcohol and caffeine consumption.
5. Misaligned teeth.
6. Inability to relax.
7. Psychological Factors: hyperfixations can lead to clenching.
8. Certain medications and drugs: use of antidepressants, antipsychotics, amphetamines, and cocaine, among other drugs.⁷

Symptoms of bruxism

Bruxism can manifest in various ways, and not everyone experiences the same symptoms. Common symptoms can include:

• Headache
• Jaw, joint or ear pain
• Aching teeth, especially upon waking up 
• Facial and temple stiffness or aches
• Jaw clenching during emotional or concentrated moments
• Temperature-sensitive teeth
• Cracked or chipped tooth enamel (the outer layer of teeth)
• Tongue or cheek indentations from repetitive biting
• Loose teeth
• Depression
• Earaches
• Eating disorders
• Muscle tenderness, often worse in the morning
• Insomnia
• Sore or painful jaw⁷

Your dentist may also notice signs of teeth grinding during a routine check which can include:

• Cracked tooth enamel
• Increased tooth wear
• Broken teeth or broken restorations
• Temporomandibular joint strain
• Sore jaw muscles
• Tooth loss (rare)
• Enlargement of the jaw muscles (rare)
• Tooth sensitivity to temperature changes⁷

Management and treatment for bruxism

Although there is no specific treatment for bruxism, treatment strategies often lean towards the management of bruxism to prevent any further damage and manage symptoms.

Self-care tips to prevent long-term damage caused by of bruxism:

• Apply ice or moist heat to sore jaw muscles
• Avoid hard or dense foods
• Refrain from chewing gum
• Stay well-hydrated
• Get adequate sleep
• Learn stretching exercises for head muscles
• Practice relaxation techniques to reduce stress

Treatment interventions of bruxism are required when there are negative consequences to the oral structures, or the symptoms start affecting your daily life.

Awake bruxism can be managed by interventions such as habit modification, relaxation therapy, and biofeedback. Awake bruxism has also been related to stress so psychotherapeutic approaches such as relaxation therapy or counselling can be implemented to help with anxiety and stresses. In this case, relaxation therapy trains the patient to relax the muscle group responsible for bruxism voluntarily. Patient counselling can lead to a decrease in tension/stress, and help to create awareness of the habit, and therefore increasing voluntary control.

Biofeedback utilises the implementation of positive feedback to enable the patient to learn tension reduction. It is based on the concept that the individual can unlearn certain behaviours. The patient can view in real-time an electromyography (EMG) monitor while the mandible is postured. In this manner, they will be able to visualise the muscle movements caused by themselves during bruxism, resulting to hightened awareness and potential reduction of that activity.⁸

Patients with sleep bruxism may require appliance therapy, which can include using a mouth guard or occlusal splints. These are worn at night, covering the occlusal surfaces (the surfaces used for chewing) of all the teeth. Hard acrylic splints are considered more effective in reducing bruxism activity, whereas soft resin splints are more difficult to adjust and can increase clenching behaviour in some patients. This may depend on the individual’s preferences and the severity of the clenching.⁹

It is recommended to perform proper sleep hygiene practices to help manage bruxism at night. This includes avoiding tobacco, coffee, and alcohol at night, and limiting physical activity or mental stimulation before sleep. In patients with drug-induced bruxism, medication withdrawal or substitution may also be considered.

Bruxism occurring in patients with neurogenic abnormalities such as dystonia, may be reduced by botox injections of the mastication muscles. Botox (botulin toxin) is a neurotoxin synthesised by Clostridium botulinum and can be used to treat various medical conditions, including bruxism.¹⁰ It works by temporarily inhibiting muscle contraction. This is achieved by impeding acetylcholine (a neurotransmitter) production, and simultaneously blocking calcium channels in nerve endings, therefore reducing neuronal communication that would otherwise activate the mastication muscles. Botox injections in the masseter and temporal muscles have been demonstrated to improve the quality of life of patients with bruxism. Furthermore, doses of <100 IU (international units) carry a low chance of adverse effects.¹⁰

Diagnosis

The diagnosis of bruxism is often based on the patient’s self-reports and clinical examination.⁴ Patients must then be well informed by their clinician about clenching, bracing and thrusting, and are asked to monitor their behaviour during a specific period (e.g., between 1-2 weeks). It is much more difficult to diagnose sleep bruxism, as the patient is not aware of their teeth grinding, unless raised as an issue by their partner, family or friends. EMG recordings can help determine both awake and sleep bruxism.

Summary

In summary, bruxism is an involuntary movement disorder characterised by the excessive grinding or clenching of teeth, occurring both during wakefulness and sleep. It can be either primary or secondary, with various factors such as stress, posture, sleeping habits, and certain medications contributing to its development. 

Symptoms of bruxism can vary widely and may include headaches, jaw pain, cracked tooth enamel, and muscle tenderness. Diagnosis relies on patient self-reports and clinical examination, with treatment strategies focusing on management and symptom relief. Management approaches include self-care tips, habit modification, relaxation therapy, biofeedback, appliance therapy such as mouth guards, and in some cases, botox injections for neurogenic abnormalities. Proper sleep hygiene practices are also recommended to manage bruxism at night. Overall, a mixed approach is often necessary to address the complex nature of bruxism effectively.