Bruxism bruxism), but also possibly grinding, and is often associated with other semivoluntary oral habits such as cheek biting, nail biting, chewing on a pen or pencil absent mindedly, or tongue thrusting (where the tongue is pushed against the front teeth forcefully). 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
Bruxism grinding. The cause of bruxism is largely unknown, but it is generally accepted to have multiple possible causes. Bruxism is a parafunctional activity, but it is debated whether this represents a subconscious habit or is entirely involuntary. The relative importance of the various identified possible causative factors is also debated. Awake bruxism is thought to be usually semivoluntary, and often associated with stress caused by family responsibilities or work pressures. Some suggest that in children, bruxism may occasionally represent a response to earache or teething. Awake bruxism usually involves clenching (sometimes the term "awake clenching" is used instead of awake