Temporomandibular Disorders (TMD) are painful conditions that primarily affect the jaw and are related to the spread of pain to the head, face, ears, neck and shoulders. It has been suspected that over 10 million people in the United States suffer from TMD. Although there is rarely a single cause of TMD, bad oral habits constitute one of the major factors affecting the health of your jaws, teeth, and gums.
Bad oral habits cause parafunction, which simply means excessive or unnecessary function. In normal functioning, when a person closes his or her mouth and brings the teeth together, there should be even contact between the teeth and the temporomandibular joint (TMJ) should be at rest in the socket of the joint. Ideally, with mouth closing, there is minimal muscle activity or joint compression. Under normal circumstances during the day there is little time spent with the upper and lower teeth in contact and the amount of force to the joint is small. This is true even during chewing.
The problem arises when there is jaw joint and muscle irritation as a result of poor oral habits. Poor oral habits include:
- Clenching and grinding teeth
- Nail biting
- Cheek and/or lip biting
- Chewing hard foods (ice, candies, etc)
- Chewing and biting pens and pencils
- Thumb sucking
- Playing a wind instrument with poor mechanics
- Holding objects with teeth (glasses, toothpicks, etc)
- Smoking (cigarettes, pipes, cigars, and chewing tobacco)
Clenching and grinding of teeth, known as bruxism, are the most common. This may entail grinding during sleep or clenching while awake. Stress is a common source for clenching and grinding. Other possible causes include abnormal bite (malocclusion), poor posture, muscle imbalances, abnormal tongue position, abnormal swallowing pattern, and mouth breathing. Prolonged use of baby bottles or pacifiers beyond two years of age will perpetuate an abnormal tongue position and swallowing pattern. During this time of growth and development, both conditions could contribute to the development of malocclusions, abnormal head-neck-jaw relationships, and a forward head posture.
Parafunctional habits will result in increased muscular activity and overloading of the jaw joint. Increased activity of the jaw muscles can lead to the development of trigger points in the muscle resulting in head and facial pain. This over-activity perpetuates joint compression, abnormal joint movement and eventual degeneration of the joint. It will also contribute to wearing down of the teeth and increased muscle activity of other head, neck, and shoulder muscles.
Most people are not consciously aware that they are performing these habits. A trained physical therapist can help to decrease these influences through behavior modification, by reestablishing a normal relationship between the joints and the muscles of the head-neck-jaw using manual therapy techniques and exercise, and by providing education for normal tongue position and breathing patterns. Dentists specializing in the treatment of temporomandibular disorders use splints to normalize the bite and to decrease parafunctional activity.
Successful treatment outcomes will require the cooperation between dentists and physical therapists and the American Academy of Orofacial Pain has made strides to foster this collaboration. Be kind to your jaws and don’t stress them. They can’t handle it.