The temporomandibular joint (TMJ) is one of the most unusual joints in the whole body. You have one on each side of your head; they can differ in size and shape and even in how they function. Because these joints are activated simultaneously by the lower jaw, you cannot move one joint without consequently moving the other. It is possible to have a problem in one joint and yet have the symptoms expressed in the other joint. You could also have pain that starts on one side of the head and migrates to the other.
A second reason the TMJ is unique is that another structure dictates its function. This other structure is our teeth. The problem of malocclusion—a poor fit between the upper and lower teeth, and a crowding together of teeth—occurs especially among people with developmental disabilities. Nearly 25 percent of the more than 80 cranial abnormalities that can affect oral development contribute to malocclusion. Malocclusion can potentially cause a misalignment within the joint capsule, causing muscles to spasm. These muscles are simply caught between two positions, the tooth position and the jaw position.
The last factor that makes the TMJ unique is that it has a disc within it, located between the ball (condyle) and the socket (fossa). The disc moves forward when the jaw opens and closes. Because the disc is a mobile structure, it is capable of moving independently and of being displaced—this is temporomandibular dysfunction (TMD), a cause of numerous problems.
TMD is a distressing syndrome. Its ultimate cause may be trauma, genetic predisposition or developmental complications, and it brings pain, limited jaw movement and sounds of clicking, popping or grating (crepitus).
Symptoms of TMJ dysfunction:
- Presence of joint sounds (clicking, popping, grating)
- Pain in the TMJ region
- Lock or limitation of movement in one or both joints
- Objective symptoms (via palpation of moving condyles, recording of joint sounds)
Other possible symptoms:
- Muscle pain
Treatment ranges from many non-invasive therapies to arthroscopy or invasive surgery.
I offer basic, non-invasive therapies:
- Removable splint therapy
- Hard appliances
- Soft appliances
- Physical therapy—at home exercises
- Nutritional guidelines
- Hypnosis referrals
- X-ray (radiographic changes)
I will incorporate this all-important and sometimes forgotten subject into my discussion with you at the time of your comprehensive dental examination.