Bruxism into three groups, namely central or pathophysiological factors, psychosocial factors and peripheral factors. The World Health Organization's International Classification of Diseases 10th revision does not have an entry called bruxism, instead listing "tooth grinding" under somatoform disorders. To describe bruxism as a purely somatoform disorder does not reflect the mainstream, modern view of this condition (see causes). The ICSD-R described three different severities of sleep bruxism, defining mild as occurring less than nightly, with no damage to teeth or psychosocial impairment; moderate as occurring nightly, with mild impairment of psychosocial functioning; and severe as occurring nightly, and with damage to
Habitual aspect The habitual aspect is a type of imperfective aspect, which does not depict an event as a single entity viewed only as a whole but instead specifies something about its internal temporal structure. Östen Dahl found that the habitual past, the most common tense context for the habitual, occurred in only seven of 60 languages sampled, including English. Especially in Turkic languages such as Azerbaijani and Turkish, he found that the habitual can occur in combination with the predictive mood. Standard English has two habitual aspectual forms in the past tense. One is illustrated by the sentence "I used to