<unk>  is excessive teeth grinding or jaw clenching. It is an oral parafunctional activity; i.e., it is unrelated to normal function such as eating or talking.<unk>  is a common behavior; reports of prevalence range from 8% to 31% in the general population. Several symptoms are commonly associated with<unk> , including hypersensitive teeth, aching jaw muscles, headaches, tooth wear, and damage to dental restorations (e.g. crowns and fillings). Symptoms may be minimal, without patient awareness of the condition. If nothing is done, after a while many teeth start wearing down until the whole tooth is gone. There are two main types of<unk> : one occurs during sleep (nocturnal<unk>  and one during wakefulness (awake<unk> . Dental damage may be similar in both types, but the symptoms of sleep<unk>  tend to be worse on waking and improve during the course of the day, and the symptoms of awake<unk>  may not be present at all on waking, and then worsen over the day. The causes of<unk>  are not completely understood, but probably involve multiple factors. Awake<unk>  is more common in women, whereas men and women are affected in equal proportions by sleep<unk> . Awake<unk>  is thought to have different causes from sleep<unk> . Several treatments are in use, although there is little evidence of robust efficacy for any particular treatment.
Bruxism
Vitalism
Rape trauma syndrome
Manganism
Cherubism
Stiff skin syndrome
Oral galvanism
Mirror syndrome