Bruxism occasional tooth grinding. It has been shown that the majority (86%) of sleep bruxism episodes occur during periods of sleep arousal. One study reported that sleep arousals which were experimentally induced with sensory stimulation in sleeping bruxists triggered episodes of sleep bruxism. Sleep arousals are a sudden change in the depth of the sleep stage, and may also be accompanied by increased heart rate, respiratory changes and muscular activity, such as leg movements. Initial reports have suggested that episodes of sleep bruxism may be accompanied by gastroesophageal reflux, decreased esophageal pH (acidity), swallowing, and decreased salivary flow. Another report suggested
Bruxism then observed high levels of bruxism-like muscular activity in rats that were allowed to watch this treatment compared to rats that did not see it. They proposed that the rats who witnessed the electrical shocking of other rats were under emotional stress which may have caused the bruxism-like behavior. Some research suggests that there may be a degree of inherited susceptibility to develop sleep bruxism. 21–50% of people with sleep bruxism have a direct family member who had sleep bruxism during childhood, suggesting that there are genetic factors involved, although no genetic markers have yet been identified. Offspring of people