Submitted by Jeffrey Bassman, Center for Headaches, Sleep & TMJ Disorders
What is the difference between grinding and clenching?
There has been a misconception and misunderstanding about the difference between grinding and clenching of the teeth. Both are forms of Bruxism. Bruxism is the involuntary gnashing, grinding, or clenching of teeth. It is usually an unconscious activity, whether the individual is awake or asleep. The actions are often associated with fatigue, anxiety, emotional stress or fear, and frequently triggered by occlusal irregularities (the way the teeth fit/come together improperly). This usually results in abnormal wear patterns on the teeth, gum tissue, bony support issues surrounding the teeth, and loose teeth. Many symptoms associated with TMJ/TMD can often be attributed to clenching and grinding, or both. The causes of both can be very similar, but by involving different activities, the consequences are slightly different.
Both clenching and grinding involve forceful contact between the upper and lower teeth.
Both involve muscles of the jaws, which keep teeth clenched or moving, as in grinding.
While grinding always involves clenching, clenching does not necessarily always involve grinding. People who grind their teeth move them repeatedly back and fourth or sideways, often creating an unpleasant sound that often wakes up sleeping partners. Clenching, on the other hand, does not include moving the jaws and teeth — just very forceful, silent pressure on the jaws and teeth. Grinding is the “moving around” of teeth during clenching (in other words, teeth grinding is teeth clenching — biting down really hard — with moving of the teeth).
Clenching puts huge pressure on the muscles and other parts of the jaws. It can cause pain in the jaws, temporomandibular joint problems (TMJ), earaches, headaches, as well as other issues. Teeth grinding also creates pressure on the jaws, so it can also cause jaw problems and similar ailments, but in addition, it can wear down teeth, cause teeth to get loose, or cause tooth enamel to chip or crack. Clenching generally results in less obvious wear to the teeth but can still result in substantial muscular soreness, pain, and damage to the jaw joint.
Clenching is especially common during periods of concentration, anger, or stress and often occurs without a person being aware of it. Clenching is a “para-functional” habit, similar to one biting their lip. A para-functional habit is the habitual exercise of a body part in a way that is other than the most common use of that body part. An issue, though, is that by pointing this habit out to a person and making them aware of it, it can actually make them do it more. Sleep grinding is not under a person’s conscious control and usually occurs throughout the night during periods of arousal as a person goes from a deeper stage of sleep to a lighter stage of sleep. This pattern may be repeated many times during the night. Extreme forces can be generated by the jaws during clenching or grinding during sleep, which can result in overuse of the jaw muscles — resulting in morning jaw pain or fatigue and jaw dysfunction. It also may be associated with a sleep disorder, such as obstructive sleep apnea.
In part two of this article, grinding and clenching will be discussed further with potential treatment.
The Center for Headaches, Sleep & TMJ Disorders is located at 141 East 46th Street Davenport, Iowa. They can be reached by telephone, 563-391-1525, or fax, 563-345-6325. Email email@example.com, or visit www.jbassmantmj.com.