Where is the
You can locate this joint by
putting your finger on the triangular structure in front of
your ear. Then move your finger just slightly forward and
press firmly while you open your jaw all the way and close
it. You can also feel the joint motion in your ear canal.
How does the
When you bite down hard, you put
force on the object between your teeth and on the joint. In
terms of physics, the jaw is the lever and the TMJ is the
fulcrum. Actually, more force is applied (per square foot)
to the joint surface than to whatever is between your teeth
because the cartilage between the bones provides a smooth
surface, over which the joint can freely slide with minimal
Therefore, the forces of chewing
can be distributed over a wider surface in the joint space
and minimize the risk of injury. In addition, several
muscles contribute to opening and closing the jaw and aid in
the function of the TMJ
In most patients, pain associated
with the TMJ is a result of displacement of the cartilage
disc that causes pressure and stretching of the associated
sensory nerves. The popping or clicking occurs when the disk
snaps into place when the jaw moves. In addition, the
chewing muscles may spasm, not function efficiently, and
cause pain and tenderness.
What causes damage to the TMJ?
- Major and minor trauma to the jaw
- Teeth grinding
- Excessive gum chewing
- Stress and other psychological factors
- Improper bite or malpositioned jaws
The pain may be sharp and searing, occurring each time
you swallow, yawn, talk, or chew, or it may be dull and
constant. It hurts over the joint, immediately in front of
the ear, but pain can also radiate elsewhere. It often
causes spasms in the adjacent muscles that are attached to
the bones of the skull, face, and jaws. Then pain can be
felt at the side of the head (the temple), the cheek, the
lower jaw, and the teeth.
A very common focus of pain is in the ear. Many patients
come to the ear specialist quite convinced their pain is
from an ear infection. When the earache is not associated
with a hearing loss and the eardrum looks normal, the doctor
will consider the possibility that the pain comes from TMJ.
There are a few other symptoms besides pain that TMJ can
cause. It can make popping, clicking, or grinding sounds
when the jaws are opened wide. Or the jaw locks wide open
(dislocated). At the other extreme, TMJ can prevent the jaws
from opening fully. Some people get ringing in their ears
What are common TMJ
TMJ pain disorders usually occur because of unbalanced
activity, spasm, or overuse of the jaw muscles. Symptoms
tend to be chronic, and treatment is aimed at eliminating
the precipitating factors. Many symptoms may not appear
related to the TMJ itself. The following are common
Headache: Approximately 80% of patients with a TMJ
disorder complain of headache, and 40% report facial pain.
Pain is often made worse while opening and closing the jaw.
Exposure to cold weather or air-conditioned air may increase
muscle contraction and facial pain.
Ear pain: About 50% of patients with a TMJ
disorder notice ear pain and do not have signs of ear
infection. The ear pain is usually described as being in
front of or below the ear. Often, patients are treated
multiple times for a presumed ear infection, which can often
be distinguished from TMJ disorder by an associated hearing
loss or ear drainage (which would be expected if there
really was an ear infection). Because ear pain occurs so
commonly, ear specialists are frequently called on to make
the diagnosis of a TMJ disorder.
Sounds: Grinding, crunching, or popping sounds,
medically termed crepitus, are common for patients with a
TMJ disorder. These sounds may or may not be accompanied by
Dizziness: Of patients with a TMJ disorder, 40%
report a vague sense of dizziness or imbalance (usually not
a spinning type vertigo). The cause of this type of
dizziness is not well understood.
Fullness of the ear: About 33% of patients with a
TMJ disorder describe muffled, clogged, or full ears. They
may notice ear fullness and pain during airplane takeoffs
and landings. These symptoms are usually caused by
eustachian-tube dysfunction, the structure responsible for
the regulation of pressure in the middle ear. It is thought
that patients with TMJ disorders have hyperactivity (spasms)
of the muscles responsible for regulating the opening and
closing of the eustachian tube.
Ringing in the ear (tinnitus): For unknown
reasons, 33% of patients with a TMJ disorder experience
noise or ringing in the ears (tinnitus). Of those patients,
half will have resolution of their tinnitus after successful
treatment of their TMJ disorder.