There is evidence that sleep bruxism is caused by mechanisms related to the central nervous system, involving sleep arousal and neurotransmitter abnormalities. Underlying these factors may be psychosocial factors including daytime stress which is disrupting peaceful sleep. Sleep bruxism is mainly characterized by "rhythmic masticatory muscle activity" (RMMA) at a frequency of about once per second, and also with 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 a link between episodes of sleep bruxism and a supine sleeping position (lying face up).
Continue reading from: