Bruxism, or teeth grinding, is highly prevalent in our society, with perhaps 5% of society having symptoms severe enough to warrant teatment. Bruxism is highly correlated with symptoms associated with Attention Deficit Hyperactivity Disorder (ADHD) in both adults and children. Among adults we observe it most in women with “Type A” personalities and/or aggressive/driven lifestyles. However, this may also only indicate that such women are more likely to seek help for this condition.
Bruxism is also highly correlated with chronic pain in general, and with headache pain in particular. Both ADHD characteristics and chronic pain are in turn correlated with cortical underarousal (a dominance of slow moving brainwave actitivty), making it attractive to suppose that bruxism may also be regarded as an underarousal condition. The theory that bruxism is causally related to a purely dental phenomenon such as malocclusion is only sparsely supported. Certainly malocclusion can give rise to chronic bruxing. However, many cases of bruxism are manifestly not grounded in problems of malocclusion. Hence, a central nervous system hypothesis is coming to the fore:
“Noctural bruxism is a definitive example of masticatory muscle hyperactivity (mouth muscles that are hyperactive during sleep). Bruxism was long thought to result from occlusal disharmony, but a growing body of evidence suggests nocturnal bruxism to be a manifestation of an abnormally low arousal threshold during sleep.” (Parker, 1990)
An association of bruxism with underarousal is also supported by observations of bruxing during anesthesia. It is also associated with excessive doses of Prozac, an anti-depressant.
In most ADHD children, nocturnal bruxism is found to be alleviated early in the NeurobiofeedbackSM training process. In adults, the training appears to proceed in fairly predictable stages: An individual is usually much more aware of daytime clenching by around session 6 or so. Pain of nocturnal bruxing is usually alleviated by session 20. However, some severe cases may require more sessions.
NOTE: Please feel free to contact us regarding more inclusive information that you feel may be helpful in expanding this section. We would be happy to include any information that will help people become more informed about Bruxism/TMJ.
Send your comments to:
Michigan Institute for Neurobiofeedback
References Parker, M.W., A dynamic model of etiology in temporomandibular disorders, JADA 120, 283 (1990).
Rugh, J.D., and Harlan, J., Nocturnal Bruxism and Temporomandibular Disorders. Advances in Neurology 49: Facial Dyskinesias, edited by Joseph Jankovic and Eduardo Tolosa, p. 329-341. Raven Press, New York (1988).
Charles McNeill, DDS (editor), Craniomandibular Disorders, Guidelines for Evaluation, Diagnosis, and Management, Quintessence, Chicago (1990).