Temporomandibular disorders

What are TMJ or TMD?
Causes of TMD
Symptoms
How we diagnose TMD
Treatment
Ways to minimise problems with TMD
Splints

What are TMJ or TMD?
Temporomandibular disorders (TMD) is a term used to include a number of disorders characterised by pain in or around the jaws joints. The problems are thought to be quite common, although only a small proportion of patients seek treatment. Adolescents and young adults are most commonly affected, though the symptoms can occur at any age.

Causes include

• injury, such as a blow to the face or car accident,
• biting on hard food
• prolonged mouth opening such as during a long dental appointment or a general anaesthetic.

Tooth clenching or grinding, especially at night, can also lead to its development. Some patients, however, are unable to identify any particular cause. Anxiety, stress and depression can also be significant factors in the development and progression of TMD.

Symptoms
The main complaint is usually jaw pain or difficulty with jaw movement, including jaw locking. Some patients have clicking of the joint, although many people with clicking jaw joints do not have pain. Other symptoms include earache, a ringing in the ears, a blocked sensation in the ears or dizziness. There may also be headaches and neck and shoulder pain. The pain is usually constant and not particularly severe though it may vary in severity over a period of time. It does not usually prevent sleep or interfere with daily activities, The pain may be episodic, can last from days to years and may recur.

How we diagnose the problem
Sometimes the way you bring the problem to us makes the diagnosis quite straight forward. However there may be cases where it is important to have a thorough examination, which should include assessment of the muscles of the head and neck and jaw, measurement of jaw movements and evaluation of any joint noises. A dental cause needs to be excluded. The teeth should be examined to identify any wear caused by grinding or any tooth interferences which might be affecting the bite. X-rays are useful in case of degenerative conditions of the joints and any other pathology in the jaws.

Treatment
Physiotherapy and jaw exercises can be helpful. Counselling and/or medication are indicated if anxiety, stress or depression are involved. Life-style changes which include relaxation, regular exercise and yoga are helpful for some patients. Other less commonly used treatments include acupuncture and biofeedback. Changes to the teeth and bite are not generally helpful unless an obvious bite interference or poor bite relationship are present. If back teeth are missing and causing a loss of jaw support, this is an indication for their replacement. Rarely, if pain and jaw limitation are persistent and there is clear evidence of degenerative changes on X-rays, joint surgery

Ways to minimise problems with TMJ and promote healing
Injuries to jaw joints and muscles are quite common and usually resolve with rest. Often the condition resolves spontaneously. It is very difficult to voluntarily rest jaw joints and muscles, especially as jaw movements often occur during sleep. During waking hours, however, it is possible to minimise activity and the simple guide-lines below allow you to avoid those jaw movements which might re-injure your joints, muscles or ligaments. Just as you would rest and support a twisted ankle, so it is necessary to reduce the load placed on your chewing muscles and joints.

1. For the next few months, cut all foods into small, bite-sized pieces and chew the food on your back teeth. Do not bite any food with your front teeth.
2. Do not eat hard crusts of bread, tough meat, hard raw vegetables or nuts or any food that requires prolonged chewing.
3. Do not use chewing gum.
4. Try to avoid opening your mouth wider than the thickness of your thumb. Support your lower jaw whilst yawning.
5. Always try to open your jaw in a hinge or arc motion.
6. Avoid protruding your jaw as, for example, when biting off a piece of bread, during conversation or when applying lipstick.
7. Should you find yourself clenching or grinding your teeth together, try to remember to keep your lips together and your teeth apart.
8. Try to breath through your nose at all times and to hold your head upright and keep your shoulders back.
9. Try to sleep on your back. If you must sleep on your side, ensure that you have adequate pillow support between your shoulder and head. Do not sleep on your jaw. Restful sleep is essential - discuss sleep problems with your doctor.
10. Realise that jaw/muscle problems are psycho-physiological in nature, related to injury and stress. Reduction of stress in your life will be of great benefit. Counselling for stress-management, and occasionally medications, may be of benefit.
11. It may be necessary for you to wear a plastic splint on your teeth during sleep, which is equivalent to using a walking stick or a crutch for a twisted ankle. The injured joint(s) and associated muscles can then be given some rest and healing can occur.

Splints
An occlusal splint is a custom-made mouthguard-like device which is worn over the upper or lower teeth at night. It is particularly helpful when a clenching or grinding habit is present. The splint may need to be worn for several months and may be helpful indefinitely if a long-term grinding habit is present.