Teeth clenching at night typically occurs as part of a condition known as sleep bruxism. Sleep bruxism involves teeth grinding and teeth clenching while sleeping. The condition can be primary, when it arises on its own, or secondary, where it results from an existing medical problem. Although the precise cause of bruxism and teeth clenching at night is not known, the disorder is thought to be associated with increased stress and is more frequently found in aggressive, competitive personality types. The use of certain drugs, such as antidepressants, may be a cause, as may sleep disorders, Parkinson's disease, and misaligned teeth.
As well as being associated with the use of legal drugs, such as antidepressants, teeth clenching in sleep is also related to the use of illegal drugs, such as ecstasy and cocaine. Heavy use of caffeine, alcohol or tobacco may also make bruxism and tooth clenching more likely. In cases where the degree of teeth grinding and teeth clenching at night is relatively mild, using any of these substances could make the problem more serious.
A number of sleep disorders are connected with clenching teeth and bruxism. Research has shown that most episodes of bruxism occur clustered together and seem to occur in response to what are known as arousals, where a person wakes briefly. In the disorder called obstructive sleep apnea, or OSA, arousals result from long pauses in breathing. These periods when breathing stops tend to be followed by teeth grinding and clenching, along with snorting or mumbling. Out of all the sleep disorders, OSA is the one which is most frequently associated with grinding and teeth clenching at night.
Depression and anxiety are often connected with bruxism. Many sufferers notice that episodes of teeth grinding and teeth clenching at night coincide with periods of increased worry and stress. A tendency to repress feelings of anger is another possible cause, and people with forceful, perfectionist, or compulsive personality traits may be more at risk.
The consequences of bruxism depend on the severity of the condition. Generally, the teeth become worn and damaged over time. Both fillings and teeth may break, and jaw pain and headaches may occur. Loss of the protective enamel from the teeth can lead to them becoming sensitive and painful. The movement of the jaw may be affected and the jaw muscles may become enlarged.
Bruxism treatment involves finding ways to minimize teeth grinding and clenching. Possible therapies include reducing stress and learning relaxation techniques. Biofeedback and hypnosis can be beneficial. Misaligned teeth may need to be corrected, and a splint or night guard may be worn over the teeth during sleep.