Bruxism: Symptoms, Types, Causes and Treatment

Bruxism is a surprisingly common but often misunderstood condition that involves repetitive jaw-muscle activity such as teeth grinding or clenching. Affecting both adults and children, bruxism can have a significant impact on oral health and overall well-being. Whether it occurs during sleep or while awake, the effects can range from mild discomfort to severe dental damage and jaw pain. In this comprehensive guide, we'll explore the key symptoms, types, underlying causes, and the latest evidence-based treatment options for bruxism.

Symptoms of Bruxism

Bruxism often flies under the radar, especially when it happens at night. However, its symptoms can be far-reaching, affecting the teeth, jaws, and even quality of life. Recognizing these symptoms early is essential for timely intervention and prevention of long-term damage.

Symptom	Description	Potential Impact	Source(s)
Tooth Wear	Flattened, chipped, or worn teeth	Increased sensitivity, fractures	1, 2, 6
Jaw Pain	Soreness or stiffness in jaw muscles	Difficulty chewing, fatigue	2, 6
Headaches	Frequent morning or tension headaches	Reduced quality of life	2, 6, 9
TMD	Temporomandibular joint dysfunction	Jaw clicking, pain, limited motion	2, 6

Table 1: Key Symptoms

Common Physical Signs

The most noticeable signs of bruxism are related to the teeth and jaw. Individuals may observe excessive wear on the biting surfaces of their teeth—sometimes leading to flattened, chipped, or cracked teeth. In severe cases, this can progress to tooth sensitivity, fractures, and even tooth loss 2 6. Abnormal tooth wear is so significant that it is sometimes associated with the development of oral tori, bony lumps in the mouth 1.

Muscular and Joint Symptoms

Jaw pain, muscle fatigue, and stiffness are frequent complaints among those with bruxism. These symptoms often become most apparent upon waking or after periods of concentration. In chronic cases, bruxism can lead to temporomandibular joint disorders (TMD), resulting in jaw clicking, limitations in mouth opening, or persistent discomfort 2 6.

Extraoral and Systemic Effects

Beyond the mouth and jaw, bruxism may manifest as frequent headaches—especially upon waking—or even ear pain due to the proximity of jaw muscles to the ear canal 2. Severe forms may also lead to loss of dental implants, periodontal lesions, and negatively impact quality of life 2.

Types of Bruxism

Bruxism is not a one-size-fits-all condition. It varies based on when it occurs and how it manifests. Understanding the types is crucial for appropriate diagnosis and management.

Type	Occurrence	Key Features	Source(s)
Sleep Bruxism	During sleep	Rhythmic or non-rhythmic jaw activity	3, 4, 6
Awake Bruxism	During wakefulness	Repetitive or sustained clenching	3, 4, 5
Non-Specific	Unspecified timing	General grinding/clenching behavior	7, 9

Table 2: Bruxism Types

Sleep Bruxism

Sleep bruxism (SB) refers to jaw-muscle activity that occurs during sleep, often without the individual's awareness. It is characterized by rhythmic (phasic) or non-rhythmic (tonic) episodes of teeth grinding or clenching. SB affects around 13% of adults and can only be definitively diagnosed with specialized assessments like electromyography or polysomnography 3 4 6.

Awake Bruxism

Awake bruxism (AB) happens during periods of wakefulness, typically involving conscious or semi-conscious jaw clenching or bracing, rather than grinding. Unlike SB, AB is often associated with stress or concentration and is reported more frequently in females 3 4 5 9.

Non-Specific Bruxism

Some studies refer to non-specific bruxism, where timing is not clearly defined or symptoms do not fit neatly into the sleep or awake categories. This grouping is generally used in research contexts when the distinction is unclear 7 9.

Diagnostic Grading

An international consensus suggests a grading system for bruxism:

• Possible: Based on self-report alone
• Probable: Self-report plus clinical examination
• Definite: Confirmed by instrumental measurement (e.g., EMG for SB) 3 4

Causes of Bruxism

The causes of bruxism are complex and multifactorial, involving interplay between psychological, physiological, and lifestyle factors. Understanding these risk factors is key to both prevention and management.

Cause Category	Examples	Contribution Level	Source(s)
Psychosocial	Stress, anxiety, behavioral issues	High	2, 5, 8, 11
Pathophysiological	Sleep arousal, neurotransmitter imbalance	Significant	5, 8, 10
Peripheral	Jaw anatomy, dental occlusion	Minimal	8, 9
Substances/Medications	Tobacco, alcohol, coffee, psychotropic drugs	Moderate	7, 10, 11

Table 3: Bruxism Causes

Psychosocial Factors

Stress and anxiety are widely recognized as major contributors to bruxism, especially the awake type. Lifestyle changes, poor sleep, and emotional distress can amplify the risk. In children, behavioral abnormalities and sleep disturbances are more prominent risk factors 2 5 11.

Pathophysiological Factors

Recent research suggests that bruxism is primarily regulated by central mechanisms in the brain, rather than by peripheral dental issues. Sleep bruxism, for example, may be part of a sleep arousal response and is influenced by neurotransmitters such as dopamine and serotonin. Movement disorders, such as those associated with Parkinson's or autism spectrum disorders, can also increase the risk 5 8 10.

Peripheral (Morphological) Factors

While dental occlusion and jaw anatomy were once considered central to bruxism's cause, current evidence suggests their role is minor, if any, in most cases 8 9.

External Substances

The consumption of tobacco, alcohol, and caffeine has been linked to increased bruxism risk. Additionally, certain medications, especially psychotropic drugs that affect neurotransmission in the brain, may trigger or exacerbate bruxism. However, the exact strength of these associations varies, and more research is needed 7 10 11.

Treatment of Bruxism

Managing bruxism is about more than just stopping teeth grinding—it's about protecting oral structures, reducing symptoms, and improving quality of life. Treatment must be tailored to each individual's needs, as there is currently no one-size-fits-all "cure."

Treatment Type	Approach/Examples	Effectiveness/Notes	Source(s)
Oral Appliances	Stabilization/Michigan splints	Most supported; reduces wear	12, 13, 15
Pharmacological	Botulinum toxin, clonazepam, clonidine	May reduce symptoms, further study needed	13, 14, 15, 16
Behavioral	CBT, relaxation, self-observation	Inconsistent evidence	12, 13, 15
Biofeedback	EMG-based feedback devices	Limited support, emerging	13, 15

Table 4: Bruxism Treatments

Oral Appliance Therapy

Custom-made oral appliances, such as stabilization splints (also known as Michigan splints), are the mainstay of bruxism management. These devices do not "cure" bruxism but protect teeth from excessive wear, distribute bite forces, and can help reduce muscle pain. Most evidence supports their use, though the specific type of splint may not significantly alter outcomes 12 13 15.

Pharmacological Management

Medications have been explored for bruxism management, especially in severe cases. Botulinum toxin type A (BoNT-A) injections into the jaw muscles have shown promise in reducing muscle activity, pain, and the intensity of bruxism episodes, though objective reductions in episode frequency are less clear. Other drugs, such as clonazepam and clonidine, also show potential benefits, but side effects and long-term safety remain concerns. Overall, pharmacological treatments are best reserved for select cases and require further research 13 14 15 16.

Behavioral and Psychological Approaches

Behavioral interventions, including cognitive-behavioral therapy (CBT), relaxation techniques, and self-monitoring (such as "SMS therapy"—self-observation, muscle relaxation, stabilization splint), aim to address the psychosocial contributors to bruxism. While intuitively appealing, evidence for their effectiveness is inconsistent 12 13 15.

Biofeedback

Biofeedback therapy, often using EMG devices to alert individuals to jaw muscle activity, is an emerging area. Some studies report reductions in bruxism episodes, but overall evidence is limited and further research is needed 13 15.

Multidisciplinary Approach

Given the multifactorial nature of bruxism, a multidisciplinary approach involving dental, medical, and psychological professionals is often recommended for optimal care, especially in complex or severe cases 2.

Conclusion

Bruxism is a multifaceted condition with wide-ranging effects on oral and overall health. While much remains to be learned, evidence-based strategies can help manage symptoms and prevent complications. In summary:

• Symptoms include tooth wear, jaw pain, headaches, and TMD, all of which can impair quality of life 1 2 6.
• Types are categorized as sleep or awake bruxism, each with distinct features and diagnostic criteria 3 4 5.
• Causes are primarily central and multifactorial, involving stress, neurological, and substance-related factors, with dental factors playing a minor role 2 5 8 9 10 11.
• Treatment focuses on oral appliances, with pharmacological and behavioral interventions as adjuncts, and emphasizes a multidisciplinary, individualized approach 12 13 14 15 16.

Early recognition and tailored management are key to minimizing the impact of bruxism and preserving oral health.