TMJ is short for "temporomandibular joint". It attaches your lower jaw (mandible) to the base of your skull on each side of your head. The TMJ acts as a hinge. It allows your mouth to open and close and move from side to side when chewing. The muscles surrounding and attached to the TMJ control its position and control jaw movements during talking, chewing and yawning.
Some people suffer from disorders affecting one or both TMJs, muscles and surrounding tissues. These disorders often cause pain and restricted jaw function. For most people, symptoms are temporary and usually go away without treatment. Discomfort in the TMJ and chewing muscles is common and usually not a cause for major concern. About seven people out of every ten have had signs of a TMJ disorder at some point in their lives. About one person in four is aware of symptoms or reports them. Of the 50 people in every 1,000 who seek treatment, only two may require surgery.
Causes of TMJ Disorders
TMJ disorders can be divided into four basic problems:
- Muscular disorders (the most common usually a tension myositis), often stress-related and caused by excessive clenching or grinding of the teeth, when the jaw muscles go into spasm and cause pain and limited function with difficulty eating.
- A disk or cartilage disorder where the disk is displaced and causes pain, clicking and locking of the joint.
- Arthritis or inflammation within the joint (this is usually associated with other joint involvement).
- An atypical facial pain which fails to fall into any obvious category. These disorders differ in nature and treatment.
The cause of TMJ disorders is not always known. In some people, symptoms may arise from an injury to the jaw, resulting from a fall or a knock to the jaw. Such an injury may disrupt the smooth motion of the jaw and cause pain or locking of the jaw joint. Tension in the jaw and grinding or clenching of the teeth are often caused by stress. Sustained emotional tension or stress plays an important role in many TMJ disorders. Emotional and physical stress can cause or aggravate TMJ disorders in susceptible people through excessive loading of the jaw joints beyond their natural capacity. The pain and function often associated with TMJ disorders can be disabling and may contribute to emotional stress or depression in itself. With chronic (long-term) TMJ disorders, the person may suffer frustration, anxiety and further stress. Most often, the onset of symptoms is during early adulthood.
Symptoms may range from mild to severely debilitating. Pain can be sharp and searing or dull and constant. Sufferers may experience a range of different symptoms which are specifically caused by the TMJ including:
- A limited range of jaw movement.
- Difficulty opening the mouth.
- A locked jaw.
- Clicking, grating or popping noises from the jaw joints.
- Pain when chewing, yawning or opening the jaw widely.
- Clenching and grinding of the teeth.
The following symptoms are non-specific to a TMJ disorder but may accompany it:
- Headaches, migraines and nausea.
- Blurred vision and dizziness.
- Earaches, loss of hearing and ringing in the ears.
- Face, neck, back and shoulder pain.
- Facial swelling.
- Sensitive teeth.
The most important step in establishing the diagnosis is a careful history and examination. X-ray examinations of your jaws and jaw joints are useful. These also help to exclude possible other causes of your pain. In certain cases, a CT scan or MRI scan may be needed to assist in the correct diagnosis of the jaw problem.
As most TMJ disorders are temporary and do not usually worsen, simple and conservative treatment often is all that is required. Most people do not require surgery. More than one type of treatment may be used at the same time. The duration of treatment will depend on the type of TMJ disorder you have. For TMJ disorders which may have taken years to develop and do not usually resolve with only a few weeks of treatment, a team approach to treatment is recommended. Our team includes an oral and maxillofacial surgeon, physiotherapists, stress management counsellors, a psychologist, a specialist rheumatologist and a specialist radiologist.
Self-care is important in any treatment, and you can do a lot to relieve your pain and discomfort. Your co-operation, motivation and compliance with the treatment plan is an important part in its success. The treatment selected should aim to alleviate jaw pain, restore your jaw function, and enable you to resume your normal daily activities. A well-designed treatment plan should also address the physical and emotional factors that may contribute to your TMJ disorder. Some treatment options are often introduced early on in the treatment phase. A modified softer diet to rest the jaw certainly helps. Resting the jaw, refraining from yawning, chewing or talking too much also helps. The application of heat with heat packs or a hot water bottle usually helps. Avoid chewing gum.
Physiotherapy Gentle muscle stretching, mobilisation, ultrasound, exercises and a modified acupuncture technique called dry needling all help to reduce pain and stiffness and improve the strength and range of motion of the muscles around the joint. This form of treatment is the mainstay of treating muscle spasm associated with the muscular component of TMJ disorders.
Relaxation and Stress managementLearning how to relax and minimise stress helps to reduce clenching or grinding of the teeth. Relaxation techniques include alteration of breathing patterns and learning to breathe "correctly". This can extend to identifying sources of stress and making necessary lifestyle changes. This may include counselling.
A wide variety of medications such as anti-inflammatories, anti-anxiety agents, sedatives, muscle relaxants or anti-depressants (if pain has been present for a long time) may be used.
Occlusal Appliance Therapy
Referred to as bite plates and splints. These appliances help to relax muscles and take the pressure off the jaw joints and teeth. These devices are usually worn at night.
Sometimes a simple procedure involving flushing out the jaw joint is used to free up a displaced cartilage.
Surgery is considered necessary where there is severe displacement of the cartilage in the joint, resulting in pain and limited function, which cannot be repositioned by other means. The most common form of surgery is an eminectomy. This involves removal of that part of the jaw joint (the eminence) which is causing obstruction of the forward movement of the cartilage. A general anaesthetic is administered to ensure that no movement occurs during the procedure. A small incision is made in front of the ear (the same incision is used in face-lift procedures) and the eminence of the bone removed. This surgery is considered relatively minor and is normally day case surgery.
Several stitches are usually required and recovery is relatively quick. Although pain in the joint usually starts to subside within a few days, swelling and discomfort may continue for up to two weeks. Your bite may also feel different at first but will return to normal when the swelling goes down. The stitches need to be removed at five to seven days following the procedure. The full period of rehabilitation can be long. Physiotherapy is often helpful during this recovering phase. It is crucial that the patient comply fully with the physiotherapy programme.
Only on rare occasions is open joint surgery necessary where the cartilage is usually removed and replaced. Serious side-effects after TMJ surgery are uncommon. While we make every attempt to minimise risks, complications can occur. Wound infections and excessive scar formation are rare complications. There is a possibility of temporary altered sensation near the ear and temple region after surgery, particularly if open joint surgery is performed. A facial nerve that causes wrinkling around the forehead and eye can be affected, but permanent damage is rare. In some cases, the surgery is not effective and the symptoms of the TMJ disorder can worsen. This risk is considered to be uncommon. To minimise this risk and increase the chances of success after surgery, you must do the entire exercise and physiotherapy programme according to your instructions. However, please realise that surgery in general is usually not required, and major surgery is very rare.