Bruxism the phrase "wailing and gnashing of teeth" is used to describe the fate of sinners in hell (). In David Lynch's 1977 film "Eraserhead", Henry Spencer's partner ("Mary X") is shown tossing and turning in her sleep, and snapping her jaws together violently and noisily, depicting sleep bruxism. In Stephen King's 1988 novel "The Tommyknockers", the sister of central character Bobbi Anderson also had bruxism. In the 2000 film "Requiem for a Dream", the character of Sara Goldfarb (Ellen Burstyn) begins taking an amphetamine-based diet pill and develops bruxism. In the 2005 film "Beowulf & Grendel", a modern reworking of
Bruxism sleep, the voluntary muscles are inactive due to physiologic motor paralysis, and the jaw is usually open. Some bruxism activity is rhythmic with bite force pulses of tenths of a second (like chewing), and some have longer bite force pulses of 1 to 30 seconds (clenching). Some individuals clench without significant lateral movements. Bruxism can also be regarded as a disorder of repetitive, unconscious contraction of muscles. This typically involves the masseter muscle and the anterior portion of the temporalis (the large outer muscles that clench), and the lateral pterygoids, relatively small bilateral muscles that act together to perform sideways