Bruxism (pronounced bruk'sihz'em) is a behavioral disorder, either brought on by or as an expression of stress. It involves repeated clenching or grinding of the teeth, usually unconsciously, and most often at night while the subject is asleep (sometimes called nocturnal bruxism). While not immediately harmful, it can lead over the medium and long term to a number of deleterious physical effects as well as causing short term discomfort.

In the short term, someone who suffers from bruxism is most likely, if they suffer ill effects, to experience headaches from the stress on their jaw and neck muscles as well as on the bones and teeth. Tooth or jaw-ache may result as well. These ailments are most often felt in the morning after extended periods of grinding during sleep, when the sufferer cannot 'catch' him or herself at it.

Longer term, damage to the teeth themselves may result. Gross physical damage to the teeth themselves such as cracking or wear on the tooth enamel can occur. In addition, teeth can be forced out of position or into odd angles from the pressure over time, requiring orthodentistry to correct. Such misaligned teeth can themselves cause disruptions to the gums, cheek and tongue.

Bruxism also contributes to TMJ, or tempomandibular joint, disorder. In these cases, the constant pressure on the jaw causes either an overbite or underbite, which in turn causes the TMJ (the jaws' 'pivot point') to dislocate slightly to allow the affected jaw to slide forward.

The problem can be corrected in a number of ways. First of all, the source can and should be treated! Stress management is highly recommended. Stress, of course, isn't always the cause; bruxism and sleep apnea are often found together, and sometimes the stress of attempting to breathe is what triggers the bruxism. In any case, a polysomnogram (sleep study) is strongly recommended by various medical studies in cases where bruxism is suspected, since often bruxism will only appear at night and can thus only be properly diagnosed during a sleep study.

The symptoms can be eased mechanically by the use of an orthodontic brace - essentially a formed shell which fits over the lower teeth and prevents the wearer from grinding his or her teeth together during the night without interfering with breathing or swallowing. These are often the least intrusive and most convenient option, since they require no external support or modification to the wearer's teeth and just pop on and off, requiring no maintenance other than a daily cleaning easily accomplished while brushing one's teeth.