Bruxism (teeth grinding) is a habit than a reflex chewing activity. Reflex activities happen reliably in response to a stimulus, without involvement of subconscious brain activity. Chewing and clenching are complex neuromuscular activities that can be controlled either by subconscious processes or by conscious processes within the brain. During sleep, (and for some during waking hours while conscious attention is distracted) subconscious processes can run unchecked, allowing bruxism to occur. Some bruxism activity is rhythmic with bite force pulses of tenths of a second (like chewing), and some has a longer bite force pulses of 1 to 30 seconds (clenching). Researchers classify bruxism as “a habitual behavior, and a sleep disorder.”
The etiology of problematic bruxism can be quite varied, from allergic reactions or medical ailments, to trauma (such as a car crash) to a period of unusual stress, but once bruxism becomes a habit, the original stimulus can be removed without ending the habit. Certain medical conditions can trigger bruxism, including digestive ailments and anxiety.
If diagnosed early, finding and eliminating the original cause(s) may cure bruxism. Later on, habitual bruxism can be treated by habit-modification. Treating associated factors can reduce or eliminate the behavior in cases where bruxism has not become habitual. From Wikipedia
For more information on bruxism treatments check out Teeth Grinding Help Program review