Bruxism is a habit that affects around 8-10% of the population. It is broadly characterised by grinding of the teeth and clenching of the jaw that causes tooth wear and breakage, disorders of the jaw (pain and limited movement) and headaches. Bruxism occurs in both children and adults but is most common in 25-44 year olds. However, most people grind and/or clench their teeth occasionally to a certain degree.
Bruxism is classified into awake bruxism and sleep bruxism. Awake bruxism is characterised by involuntary clenching of the teeth and jaw bracing in reaction to certain stimuli. There is generally no tooth grinding with awake bruxism. Sleep bruxism is characterised by automatic teeth grinding with rhythmic and sustained jaw muscle contractions.
Many studies have found that there are other characteristics associated with sleep bruxism because it rarely occurs alone. Sleep bruxism occurs as a response to arousals during sleep (periods of awakening), indicating that it may also be a sign of a sleep disorder. Nearly 80% of bruxism episodes occur in clusters during sleep and are associated with these arousals. The strongest association has been found between sleep bruxism and Obstructive Sleep Apnoea (periods of stopping breathing during sleep), which is a condition that is often accompanied by daytime sleepiness and non-restorative sleep. Individuals with OSA have many arousals during the night due to their breathing difficulties. The termination of the apnoea event is often accompanied by a variety of other events such as snoring, gasping, mumbling and teeth grinding. OSA has been found to have the highest risk factor for tooth grinding during sleep than any other sleep disorder.
Significant associations with sleep bruxism have also been found with other sleep conditions such as sleep talking, hypnagogic (state of consciousness between sleep and wakefulness) hallucinations, violent or injurious behaviours during sleep and REM sleep disorders. Psychological disorders such as stress and anxiety are also known to exacerbate teeth grinding during sleep. In one study, around 70% of sleep bruxists related their nocturnal teeth grinding to stress and anxiety. Bruxism is also more prevalent in individuals who regularly use alcohol, tobacco and caffeine (6 cups or more per day).
There is no specific cure for bruxism and it is important to manage the consequences of the disorder. Various preventative measures including mandibular advancement devices, drugs, stress management and occlusal splints have been used. However, all but occlusal splints have demonstrated adverse effects which reduces their appropriateness.
The reason why bruxism occurs is not always clear and sometimes can be difficult to diagnose. However, these are some of the possible factors:
Stress and other Psychological Components
Mental disorders, anxiety, stress and adverse psychosocial factors are significantly related to tooth grinding during sleep and it has been found that nearly 70% of bruxism occurs as a result of stress or anxiety. It is well documented that job related stress is detrimental to good sleep and as a consequence can be responsible for daytime sleepiness. But, it is also the most significant factor associated with bruxism. One study found that shift workers who suffered stress due to dissatisfaction with their shift-work schedule were more susceptible to bruxism than those who were satisfied and not stressed. Interestingly, the men in this study demonstrated high levels of job stress, depressive symptoms and bruxism whereas none of these symptoms were significant for the women. These adverse symptoms were particularly evident in male workers who experienced low social support from supervisors or colleagues.
Many physical ailments have psychological components that may influence a person’s vulnerability to illness as well as their ability to recover. Stress levels and personality characteristics are often considered as initiating, predisposing and perpetuating factors for several diseases. The workplace offers a unique environment where stress and personality play a major role in performance. Personality variables include the individual’s coping style both in perception and coping techniques. Some people are less resilient to stress and therefore suffer more from the physical and psychological consequences. Previous research findings point to the possibility of a link between bruxism and the work environment, especially the coping strategies for work related stressful demands. Some people of course, may be exposed to high levels of stress unrelated to their job, but still affect bruxism.
Demographic and lifestyle factors such as young age, higher educational status, smoking, caffeine intake and heavy alcohol consumption are associated co-factors of bruxism. The use of psychoactive substances (tobacco, alcohol, caffeine, or medications for sleep, depression, and anxiety) increases arousal and leads to problems falling asleep, staying asleep and daytime sleepiness. Bruxism is significantly higher in individuals whose lifestyle includes the use of these psychoactive substances.
It is known that bruxism rarely occurs alone. Research has consistently found that bruxism is found more frequently in those individuals who have an existing sleep disorder such as snoring, breathing pauses during sleep and Obstructive Sleep Apnoea (OSA). Other parasomnias such as sleep talking, violent or injurious behaviours during sleep, sleep paralysis, hypnagogic/hypnopompic hallucinations (semi-consciousness between sleep and wake) are also more frequently reported by bruxists and tooth grinding individuals. Of these, OSA appears to be the highest risk factor as it is associated with an arousal response. The termination of the apnoea event is often accompanied by a variety of mouth phenomena such as snoring, gasps, mumbling and tooth grinding.
Patients may present a variety of symptoms, including:
- Stress and tension
- Eating disorders
- Sore or painful jaw (TMJ discomfort)
- Facial myalgia (muscle pain)
- Tightness and stiffness of the shoulders
- Sleep disruption of the individual as well as the bed partner
- Abnormal tooth wear
- Fracture of the teeth
- Inflammation and recession of the gums
- Excess tooth mobility
- In extreme cases, premature loss of teeth
It’s important to stress that these symptoms may not necessarily indicate a straight forward cause-effect relationship. For example, depression can conceivably be an effect of persistent TMJ discomfort rather than its cause.
For more information and to get an accurate diagnosis, contact your dentist.
While the symptoms of bruxism in adults can be treated, the condition usually cannot be cured. Treatment focuses on relieving acute symptoms and limiting permanent sequelae. Treatment should be provided jointly by the patient’s physician and dentist.
A variety of treatments can be used depending on what is causing the bruxism. The success of treatment is determined by symptoms resolution and improved mandibular range of motion.
The goals of treatment are to reduce pain, prevent permanent damage to the teeth, and reduce clenching as much as possible.
To help relieve pain, there are many self-care steps you can take at home. For example:
- Apply ice or wet heat to sore jaw muscles. Either can have a beneficial effect.
- Avoid eating hard foods like nuts, candies, steak.
- Drink plenty of water every day.
- Get plenty of sleep.
- Learn physical therapy stretching exercises to help restore a normal balance to the action of the muscles and joints on each side of the head.
- Massage the muscles of the neck, shoulders, and face. Search carefully for small, painful nodules called trigger points that can cause pain throughout the head and face.
- Relax your face and jaw muscles throughout the day. The goal is to make facial relaxation a habit.
- Try to reduce your daily stress and learn relaxation techniques. Stress reduction can be achieved by a number of techniques such as visual imagery and autosuggestion, aversive conditioning (such as awakening the patient during episodes of teeth grinding), massed negative practice (the patient voluntarily clenches the teeth for 5 seconds and then relaxes the jaw for 5 seconds), pharmacologic therapy to suppress REM sleep, changes in sleep position (lying supine with neck and knee support allows the lower jaw to rest), and a soft food diet.
To prevent damage to the teeth, mouth guards or dental appliances (dental splints) have been used since the 1930s to treat teeth grinding, clenching, and TMJ disorders. A splint may help protect the teeth from the pressure of clenching.
A splint may also help reduce clenching, but some people find that it makes their clenching worse. In others, the symptoms go away as long as they use the splint, but pain returns when they stop or the splint loses its effectiveness over time.
There are many different types of splints. Some fit over the top teeth, some on the bottom. They may be designed to keep your jaw in a more relaxed position or provide some other function. If one type doesn’t work, another may.
As a next phase after splint therapy, orthodontic adjustment of the bite pattern may help some people. Surgery should be considered a last resort.
Finally, there have been many approaches to try to help people unlearn their clenching behaviors. These are more successful for daytime clenching, since night-time clenching cannot be consciously stopped.
In some people, just relaxing and modifying daytime behavior is enough to reduce night-time bruxism. Methods to directly modify night-time clenching have not been well studied. They include biofeedback devices, self-hypnosis, and other alternative therapies.
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