Bruxism during the day. The ICDS-R defined sleep bruxism as "a stereotyped movement disorder characterized by grinding or clenching of the teeth during sleep", classifying it as a parasomnia. The second edition (ICSD-2) however reclassified bruxism to a "sleep related movement disorder" rather than a parasomnia. Alternatively, bruxism can be divided into "primary bruxism" (also termed "idiopathic bruxism"), where the disorder is not related to any other medical condition, or "secondary bruxism", where the disorder is associated with other medical conditions. Secondary bruxism includes iatrogenic causes, such as the side effect of prescribed medications. Another source divides the causes of bruxism
Bruxism is growing, but still not conclusive. Some consider emotional stress to be the main triggering factor. It has been reported that persons with bruxism respond differently to depression, hostility and stress compared to people without bruxism. Stress has a stronger relationship to awake bruxism, but the role of stress in sleep bruxism is less clear, with some stating that there is no evidence for a relationship with sleep bruxism. However, children with sleep bruxism have been shown to have greater levels of anxiety than other children. People aged 50 with bruxism are more likely to be single and have a