The Temporomandibular Joint (TMJ)
The temporomandibular joint (TMJ) is a small joint located in
front of the ear where the skull and lower jaw meet. It permits the
lower jaw (mandible) to move and function.
TMJ disorders are not uncommon and have a variety of symptoms.
Patients may complain of earaches, headaches and limited ability to
open their mouth. They may also complain of clicking or grating
sounds in the joint and feel pain when opening and closing their
mouth. What must be determined, of course, is the cause.
What Causes TMJ Disorders?
Determining the cause of a TMJ problem is important, because it
is the cause that guides the treatment.
Arthritis is one cause of TMJ symptoms. It can result from an
injury or from grinding the teeth at night. Another common cause
involves displacement or dislocation of the disk that is located
between the jawbone and the socket. A displaced disk may produce
clicking or popping sounds, limit jaw movement and cause pain when
opening and closing the mouth.
The disk can also develop a hole or perforation, which can
produce a grating sound with joint movement. There are also
conditions such as trauma or rheumatoid arthritis that can cause the
parts of the TMJ to fuse, preventing jaw movement altogether.
| Anatomy of the TMJ |
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The TMJ is a hinge and gliding joint and is
the most constantly used joint in the body. The round upper
end of the lower jaw, or the movable portion of the joint,
is called the condyle; the socket is called the articular
fossa. Between the condyle and the fossa is a disk made of
cartilage that acts as a cushion to absorb stress and allows
the condyle to move easily when the mouth opens and closes. |
The Joint, the Muscles or Both are the Problem
Stress may trigger pain in the jaw muscles that is very similar
to that caused by TMJ problems. Affected patients frequently clench
or grind their teeth at night causing painful spasms in the muscles
and difficulty in moving the jaw. Patients may also experience a
combination of muscle and joint problems. That is why diagnosing TMJ
disorders can be complex and may require different diagnostic
procedures.
| Function of the TMJ |
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| Temporomandibular joint — Normal closed position.
Jawbone is separated from skull by a soft disk that acts as
a cushion when you chew, speak or swallow. |
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| Temporomandibular joint — Noraml open position. Disk
stays in place when jaw is in use. |
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| Temporomandibular joint — Abnormal. Disk is pulled
forward when jaw is in use, causing the bone structures to
grind together. |
The Role of the Oral and Maxillofacial Surgeon
When symptoms of TMJ trouble appear, an oral and maxillofacial
surgeon should be consulted. A specialist in the areas of the mouth,
teeth and jaws, the oral and maxillofacial surgeon is in a good
position to correctly diagnose the problem.
Special imaging studies of the joints may be ordered and
appropriate referral to other dental or medical specialists or a
physical therapist may be made.
Range of Possible Treatment
TMJ treatment may range from conservative dental and medical care
to complex surgery. Depending on the diagnosis, treatment may
include short-term non-steroidal anti-inflammatory drugs for pain
and muscle relaxation, bite plate or splint therapy, and even stress
management counseling.
Generally, if non-surgical treatment is unsuccessful or if there
is clear joint damage, surgery may be indicated. Surgery can involve
either arthroscopy (the method identical to the orthopaedic
procedures used to inspect and treat larger joints such as the knee)
or repair of damaged tissue by a direct surgical approach.
Once TMJ disorders are correctly diagnosed, appropriate treatment
can be provided.
| Treatment Options for TMJ Disorders |
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| Bite splints or guards are commonly used to
treat TMJ disorders. |
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| Some of the TMJ surgical options your OMS may consider
include (a) Arthrocentesis — flushing fluid from the joint
and gently stretching it. (b) Arthroscopy — using a
miniature telescoping instrument to diagnose and repair the
joint. (c) Arthrotomy — open joint surgery for more
complex cases. |
ORAL AND MAXILLOFACIAL SURGEONS: AN IMPORTANT LINK
Oral and maxillofacial surgery is the specialty of dentistry that
includes the diagnosis, surgical and adjunctive treatment of
diseases, injuries and defects involving both the functional and
aesthetic aspects of the hard and soft tissues of the oral and
maxillofacial region.
An oral and maxillofacial surgeon is a graduate of an accredited
dental school who has completed an additional four or more years of
training in an accredited, hospital-based oral and maxillofacial
surgery residency program.
Oral and maxillofacial surgeons are an important link in the
referral network for primary care providers. Through appropriate
referrals, patients can be provided with expedient and
cost-effective health care for conditions relating to the specialty
of oral and maxillofacial surgery.
© 2005 American Association of Oral and Maxillofacial Surgeons (AAOMS).
All rights reserved.
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