Temporo-mandibular joint disorder (TMD)
Temporo-mandibular joint disorder (TMD) is an umbrella term given to pain and dysfunction associated with the teeth, jaw muscles and jaw joint, as well as facial, back of the head, neck and shoulder pain. Dental names include temporo-mandibular joint pain dysfunction syndrome, and myofacial pain.
These problems are not unique to the head and neck and fit into a broader classification of musculo-skeletal disorders. There are many types of health care practitioners that assist patients with these problems: eg physiotherapists, chiropractors, osteopaths, masseurs, as well as Alexander technique, Bowen and Feldenkrais practitioners. Pain and dysfunction associated with the jaw muscles often affects the teeth and is of particular interest to dentists.
The teeth, muscles and jaw joint are generally organised to work in a harmonious, coordinated fashion, so that we can eat, communicate and engage in the range of normal human activities. Many patients work their jaw muscles (grind their teeth) to improve their concentration, esp those engaged in sports. This is very common among students at exam times, during marriage and divorce, buying a house etc.
However if the system becomes overworked or overloaded, this can result in pain and dysfunction and permanent damage to the teeth and joint.
Symptoms associated with TMJ disorders may be:
- Biting or chewing difficulty or discomfort
- Clicking, popping, or grating sound upon jaw movement
- Dull, aching pain in the face
- Earache/headache (particularly in the morning)
- Pain or tenderness of the jaw
- Restricted jaw opening
- Neck and shoulder pain
With use (age) it is common to see wear to both bone and cartilage in the joint. Joint clicking and minor deviations in joint movements are common. Pain is the conventional signifier of TMD
- Bruxism (repetitive unconscious clenching/grind, often at night)
- Excessive jaw movements/thrusting beyond the normal range (parafunction)
- Excessive gum chewing, nail biting, large food bites, hard chewing foods
- Mal-alignment and anomalies of tooth surfaces and the bite
- Degenerative joint disease
Diagnosis is generally based on:
- location of the pain, stiffness and soreness
- range of jaw movement
- the presence of joint noises
- your bite, tooth wear and tooth movement
To assist diagnosis, your dentist may recommend:
- Plaster dental casts
- X-ray examination
- Completion of a questionnaire and pain diagram
Clenching and grinding may occur during the day, where it may be brought to the patient’s conscious awareness; or at night, where a patient may wake with a sore jaw area and/or break a tooth at breakfast.
Treatment generally aims to
- Change the patient’s behaviours
- Reduce activity in the jaw muscles.
- Pain relief
- Repair the damage that often causes alterations in the teeth and joints.
This may include:
- Counseling, stress management or general relaxation methods
- Jaw specific relaxation exercises designed to reduce muscle activity
- Jaw specific rest strategies including a soft diet and limitation of jaw opening; and isometric exercise to re-program muscle activity
- Application of warmth to some jaw muscles via a heat pack
- Anti-inflammatory painkillers for muscular facial pain, headaches and jaw joint pain
- Muscle relaxant medication to help relax the jaw muscles
- Repairing anomalies and damage to the teeth and bite may be required. This may be as simple as minor reshaping of some teeth to remove occlusal interferences; or major reshaping using the full range of restorative methods available today.
- An occlusal spilnt (night guard), worn at night, is made of moulded hard plastic that fits over the upper or lower teeth; this modifies muscle activity and prevents further teeth surface wear.
- Surgery is reserved where other therapeutic methods have failed.
In the majority of cases symptoms reduce after a single consultation providing information, strategies for rest, relaxation and muscle activity modification; the judicial use of painkillers and heat-packs. Symptoms tend to recur periodically.
In a minority of cases an occlusal splint and/or assistance from a practitioner providing various forms of physical therapy are required. Behaviour modification therapy from a psychologist may be beneficial.
Surgery is very uncommon
Broad information on TMD, bruxism and myofacial pain syndrome is available on Wikipedia via the Internet.
DR. MALCOLM J. GRENNESS
B.D.Sc., L.D.S., M.Med.Sc., PhD, F.R.A.C.D.S
Call: (03) 6224 3575
158 Collins Street, Hobart
Monday – Friday 8.45am-5.15pm
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