Temporomandibular disorders can be brought on in many ways. For instance, direct trauma might be caused by a blow to the jaw or a car accident. Jaw joints and muscles can also be overloaded by activities or habits like teeth clenching, grinding or frequent gum chewing. Stress may help bring on temporomandibular disorders. A combination of all these factors acting at the same time may also lead to TMD onset.
These disorders can be acute or chronic. Acute problems include conditions which appear rapidly but may last only a short while. Such problems usually respond well to conservative treatment. However, if the problem persists, it may become chronic and require various treatment approaches.
The mandible or lower jaw attaches to the skull through the temporomandibular joints. These joints allow normal jaw movements including chewing, mouth opening and closing. TMJs are shaped by the condyle, a rounded head in the lower jaw which goes into a fossa in the skull. Between the two, a fibrous disc acts as a buffer during the jaw movements. Several ligaments hold the disc in place on the condyle.
Most problems in the temporomandibular joints can be linked to mechanical or inflammatory causes. Mechanical problems often appear if the articular disc is displaced (moved) from its normal position in the joint. Since the disc is out of alignment, it can cause different kinds of sounds or ‘clicks’. Sometimes the disc may be so far out of position that the mouth cannot be opened. This is called a closed lock. The opposite condition, known as open lock, happens if the condyle becomes dislocated during extended mouth opening. Mechanical problems like these can cause pain when the joints are used.
Common inflammatory problems include osteoarthritis or inflammation of the TMJ ligaments. With osteoarthritis, changes to the bone or remodelling of joint surfaces can cause pain. A grating sound (crepitus) may be heard or a bone-on-bone sensation may be felt when the jaw moves. Osteoarthritis may also change the bite. Inflammation of the capsule, the ligament surrounding the joint, is an acute condition which makes jaw movement very painful.
Overloading the jaw muscles can cause different types of muscular conditions. Fatigue, tightness and pain are common symptoms. Pain may be constant, or only felt when the jaw is moved. Muscle tension and pain can also make it difficult to open the mouth.
With TMDs, affected muscles may ‘refer’ pain to another location in the head. Earaches, headaches or even toothache might be caused by a pain referral coming from an affected jaw muscle. The nerve pathways of pain transmission are organized in the head and neck area so that, in unusual circumstances, the brain can interpret pain information as if it was located elsewhere. For instance, a patient experiencing pain in the jaw muscles or TMJs might experience referred pain in the temple, which would feel like a headache.
Those who have pain or discomfort in the jaw should first see their family dentist. If there is also a toothache, the general dentist can rule out problems with the teeth and refer to a specialist if necessary. If symptoms like earache or headache are reported, they can be investigated by a family doctor or another medical specialist. Once dental and medical problems are ruled out by the dentist and the family doctor respectively, the patient can be referred to a TMD specialist for further assessment and treatment.
Once the type of TMD has been diagnosed, different treatment options can be recommended. Usually, temporomandibular disorders are treated conservatively. Simply understanding the problem can help the patient learn self-care techniques. For instance, bad habits like daytime clenching of the teeth or frequent gum chewing may add to the problem.
An intra-oral splint appliance may help reduce pain. Non-steroidal anti-inflammatory medications, analgesics and muscle relaxants may be used. Some of these drugs are available in topical formulation. If muscles are inflamed or in spasm, physical therapy may also help.
If a problem does not resolve with conventional treatment, alternatives can be explored. In some chronic cases, a team approach involving experts from different areas might be used. For instance, dental specialists, doctors, physical therapists and psychologists may all work together to solve the problem.
At times TMJ disorders may be severely painful and cause problems. The good news is that TMDs do tend to spike and usually lessen as we grow older.