Temporomandibular disorders (TMD) occur as a result of problems
with the occlusion, jaw joint (called the temporomandibular joint,
or TMJ), and surrounding facial muscles that control chewing and
moving the jaw.
What is the temporomandibular joint?
The
temporomandibular joint is the hinge joint that connects the lower
jaw (mandible) to the temporal bone of the skull, which is
immediately in front of the ear on each side of your head. The
joints move smoothly up and down and side to side and enabling you
to talk, chew, and yawn. Muscles attached to and surrounding the
jaw joint control its position and movement.
What causes TMD?
The cause of TMD is not clear, but
dentists believe that symptoms arise from problems with the muscles
of the occlusion and/or with the parts of the joint itself.
Injury to the jaw, temporomandibular joint, or muscles of the
head and neck, such as from a heavy blow, can cause TMD. Other
possible causes include:
- Grinding or clenching the teeth, which puts a lot of pressure
on the TMJ
- Dislocation of the soft cushion or disc between the ball and
socket
- Presence of osteoarthritis or rheumatoid arthritis in the
TMJ
- Stress, which can cause a person to tighten facial and jaw
muscles or clench the teeth
What are the symptoms of TMD?
People with TMD can
experience severe pain and discomfort that can be temporary or last
for many years. TMD is seen most commonly in people between the
ages of 20 and 40, and occurs more often in women than in men.
Common symptoms of TMD include:
- Pain or tenderness in the face, jaw joint area, neck and
shoulders, and in or around the ear when you chew, speak, or open
your mouth wide
- Limited ability to open the mouth very wide
- Jaws that get "stuck" or "lock" in the open- or closed-mouth
position
- Clicking, popping, or grating sounds in the jaw joint when
opening or closing the mouth (which may or may not be accompanied
by pain)
- A tired feeling in the face
- Difficulty chewing or a sudden uncomfortable bite -- as if
the upper and lower teeth are not fitting together properly
- Swelling on the side of the face
Other common symptoms include toothaches, headaches, neckaches,
dizziness, and earaches and hearing problems.
How is TMD diagnosed?
Because many other conditions
can cause similar symptoms -- including a toothache, sinus
problems, arthritis, or gum disease -- your dentist will conduct a
careful patient history and clinical examination to determine the
cause of your symptoms. He or she will examine your
temporomandibular joints for pain or tenderness; listen for
clicking, popping, or grating sounds during jaw movement; look for
limited motion or locking of the jaw while opening or closing the
mouth; and examine bite and facial muscle function.