TMJ ...
Temporomandibular Joint Dysfunction
What is it?
"TMJ" stands for TemporoMandibularJoint, and "TMD"
stands for TemporoMandibular Dysfunction of the jaw joint. There are two TMJs,
one in front of each ear, connecting the lower jaw-bone (the mandible) to the
skull. The joints allow the jaw to move up and down, side-to-side, and forward
and back-all the mobility necessary for biting, chewing and swallowing food,
for speaking and for making facial expressions. It is by far the most complex
and most over-worked joint in the human body. 
Overview
Over 10 million people in the
USA suffer from TMJ or temporomandibular joint syndrome, a condition in which
the temporomandibular joint does not function correctly and because of that
usually generates pain of varying degrees.
This joint connects the
temporal bone, which is the bone that forms the sides of the skull with the
jawbone. This condition produces pain in the muscles and joints of the jaw that
frequently radiates to the ear, face, head, neck, and shoulder.
There
may also be difficulty opening the mouth all the way, with clicking, grinding,
and popping noises sometimes occurring during chewing and movement of the
joint. Headaches, dizziness, pain and pressure behind the eyes, ear pain and/or
ringing in the ears, together with difficulty opening and closing the mouth
normally are other symptoms.
Signs and symptoms
Signs and symptoms of TMJ disorders may include one or a combination of the following:
- Aching pain in and around the ear
- Recurrent Headache
- Facial pain
- Jaw Tenderness
- A clicking sound or grating sensation with opening the mouth or chewing
- Locking of the joint, making it difficult to open or close the mouth
- Inability to chew certain foods, or eating only a soft diet due to pain
- An uneven bite, because one or more teeth are making premature contact
- Generalized neck ache/or stiffness
- Ringing in one or both ears
- Dizziness
- Uncomfortable bite
Varying degrees of pain and tenderness may be
experienced, even when there is no movement of the jaw. Chronic tension and
anxiety may cause the increased tone of jaw muscles together with grinding of
the teeth (bruxism), at night. A dull discomfort in the jaws and muscles upon
awakening in the morning or an ache that progressively worsens throughout the
day may be the result of this unconscious activity during sleep.
Understandably, this overuse of the TMJ and its supporting muscles may
cause pain by means of constant joint compression accompanied by chronic
jaw-joint muscle fatigue and spasm resulting in diminished micro-circulatory
blood supply and in the engorgement of inflammatory chemical by-products.
However, in most cases, the pain or tenderness worsens when the jaw is in
motion or upon chewing as the joints and muscles are called upon to function.
Jaw joint sounds are common but do not always signal a problem. If there's no
pain or limitation of movement associated with jaw clicking, an active TMJ
disorder probably does not exist.
Causes
Normally, the TMJ
allows the jaw to open and close smoothly. The lower jaw has rounded ends
(condyles) that fit into a concave indentation (fossa) located in the bottom of
the skull. They glide in and out of the joint socket (glenoid fossae) when you
talk, chew or yawn. There is also a disk made of cartilage between each condyle
and the inner surface of the glenoid fossae to protect, and absorb shock,
keeping the movement smooth and frictionless.
If movements of your left
and right TMJs aren't synchronized, abnormal stresses are generated eventually
resulting in varying degrees of pain and and other symptoms that can effect not
only the jaw, but also the head, face, neck and shoulders together with the
ability to swallow properly. Furthermore, the combination of symptoms over a
prolonged period of time leads to varying degrees of depression and sleep
disorders - perpetuating a vicious cycle.
An improperly aligned bite
can contribute to dislocation of the small movable (floating) disc located on
top of the condyle, between the jaw and the skull (see graphic above). Pain in
the TMJ can also result from degeneration of, or trauma to, the joint proper,
such as by a blow to your jaw resulting in injury to muscles/ligaments and
disk, generating a reactive inflammation with muscle splinting. Chronic tension
and anxiety may cause the grinding of teeth (bruxism), often at night, or the
maintaining of clenched jaws. This overuse of the TMJ and supporting muscles
may result in varying degrees of pain and/or discomfort, and dysfunction of the
jaw and supporting structures.
The TMJs are embedded in an intricate
web of pain-sensitive nerves and delicate muscles. The disk that separates the
lower jaw from the skull can slip out of position or a condyle, upon which it
is positioned, can become dislocated. Either occurrence results in sometimes
severe pain and/or the inability to open the mouth or jaw fully. The force of
normal chewing and of clenching or gritting the teeth creates great tension and
pressure in that area of the face.
The cartilaginous disk that cushions
the joint may become displaced or even wear out, causing bone-on-bone contact
within the TMJ, rather than smooth frictionless gliding. In some instances, a
misalignment of the jaw and teeth prevents synchronous, coordinated operation
of the joints.
The most common underlying causes of TMJ are
anatomic-structural abnormalities, a poor bite, missing molar teeth, direct
injury to the face and jaw, such as blunt-force trauma or "whiplash", with
aggravating factors being emotional stress clenching or grinding the teeth
(bruxism), arthritis of the joint and poor head-neck posture. Habits, such as
one-sided gum chewing, eating , and thumb sucking, can aggravate the problem.
Screening and Diagnosis
Dr. Steed will inquire
as to signs and symptoms: how long they have been present, whether there has
been an injury to the jaw, and whether there has been recent dental treatment
undertaken? In addition, she will listen to any sounds the jaw-joint makes and
measure the range of motion of your jaw. Examining the bite can reveal
abnormalities in the alignment of the teeth and in the movement of the jaw.
Conditions such as a high filling, a tipped tooth, displaced teeth due to
previous extractions or certain inherited characteristics can cause
misalignments and subsequent pain.
Dr. Steed can also determine if
there are signs of chronic grinding of the teeth, by examining the wear
patterns. Feeling the joint while in motion will also assist her in her
diagnosis. Carefully examining the muscles that open and close the jaw can
reveal a muscular component of the pain, if it is present. X-ray studies are
generally made in the office to evaluate the bony structures of your mouth and
to show the position of the jawbone in relation to the joint socket, thus
allowing Dr. Steed to determine whether or not function is abnormal and whether
the disk is dislocated.
Due to the variance in development of anatomic
structures involving the teeth, jaws and head, together with the many varied
problems which may be involved with TMD, a thorough examination with
appropriate tests, conducted by a doctor with advanced training in TMD, is
essential in determining a proper diagnosis. Once this step is accomplished,
proper treatment may be provided in an attempt to resolve the problem and to
alleviate or greatly reduce the suffering. In doing so, permanent deterioration
may be avoided.
Treatment Options
Dr. Steed
believes it imperative to begin with the most conservative and noninvasive
treatment first. Inasmuch as Dr. Steed's vast experience has shown that only 2%
of patients require surgical intervention, it is only logical to proceed with
conservative, reversible treatment first, with surgical intervention reserved
as a last resort - after all else has failed.
Aside from requesting the
avoidance and overuse of the jaw, one or more of the following treatments may
be recommended:
- Anti-inflammatory medications. To reduce inflammation and lessen pain, the recommendation may be made to take aspirin or another nonsteroidal anti-inflammatory drug such as ibuprofen (Advil, Motrin, etc.). For severe pain and inflammation, corticosteroid drugs injected into the joint may provide relief.
- Heat or cold. Appling warm, moist heat to the facial muscles or ice directly to the site of the TM joint may provide temporary relief.
- Corrective dental treatment. Depending on the examination findings, it may be recommended that the biting surfaces of your teeth be balanced through the replacement of missing teeth, or the replacing of needed fillings or crowns.
- Appliance. If the TMJ is misaligned, Dr. Steed may recommend a specially made plastic composite orthotic (appliance) to be worn over the teeth, to help align the upper and lower jaws, decompress the joints to allow for recapture of the dislocated disk, place the joints in their correct position and thereby promote healing and stabilization by scar development and the establishment of corrective muscle engramming (muscle-memory).
- Night guard appliance. If teeth grinding exists, a night guard appliance, which is generally soft or firm device inserted over the teeth, can help prevent grinding and excessive wear.
- Arthrocentesis. This procedure involves insertion of a needle so that fluid can be removed to decompress the joint of inflammatory exudates.
- Orthodontia. . In a relatively small number of cases, orthodontia is required after symptoms have subsided and the jaw is balanced. Orthodontia (know as Phase II treatment), stabilizes the bite and all the supporting muscles of the face, jaw and neck. This, however, depends on whether or not Phase I treatment is successful or not.
- Surgery. If none the above approaches prove successful, consideration may be given to surgical intervention. However, the need for such surgery is rare.
Treatment also routinely involves behavior
modification and a period of time utilizing an Intraoral Mandibular Orthopedic
Repositioning Appliance (MORA). Depending on the complexity of the condition,
some patients may require prescription medications, physical therapy
modalities, counseling/biofeedback together with referral to other health care
professionals. Fortunately, if early treatment is instigated, a very small
percentage of afflicted patients require surgery, although some do require
diagnostic/therapeutic injections.
Approximately 20 to 30% of TMD
patients require stabilization therapy in the form of orthodontia (braces),
crowns (caps), crown and bridges, partial dentures, complete dentures (if the
patient has no teeth - edentulous) or possibly a combination of these
approaches. However, the greater majority of patients need no further treatment
or require only night time wear of a night guard (appliance), if they clench or
grind their teeth during sleep. Occasionally patients need to wear the
intraoral appliance during sports activities due to the physical exertion to
the muscles surrounding the jaw-complex and hence the jaw-joint itself.