Temporal muscle this portion results in retrusion of the mandible. When lower dentures are fitted, they should not extend into the retromolar fossa to prevent trauma of the mucosa due to the contraction of the temporalis muscle. The temporalis is likely to be involved in jaw pain and headaches. Bruxism, the habitual grinding of teeth typically while sleeping, and clenching of the jaw while stressed can lead to overwork of the temporalis and results in pain. A myotendinous rupture of the temporalis can occur during a seizure due to extreme clenching of the jaw. During a seizure the contralateral temporalis muscle can
Bruxism a link between episodes of sleep bruxism and a supine sleeping position (lying face up). Disturbance of the dopaminergic system in the central nervous system has also been suggested to be involved in the etiology of bruxism. Evidence for this comes from observations of the modifying effect of medications which alter dopamine release on bruxing activity, such as levodopa, amphetamines or nicotine. Nicotine stimulates release of dopamine, which is postulated to explain why bruxism is twice as common in smokers compared to non-smokers. Many studies have reported significant psychosocial risk factors for bruxism, particularly a stressful lifestyle, and this evidence