What is TMJ?

TMJ stands for Temporomandibular joint, otherwise known as the jaw joint. There are two of these joints located in front of each ear. They are formed by the temporal bone of the skull (temporo) with the lower jaw (mandible) hence Temporomandibular. They are the point at which the lower jaw attaches to the base of the skull. By placing your fingers in front of your ears on both sides of your face, you can feel the movement of the mandible in the TM joints. Although it is a simple exercise to locate the TM joint, it is the most complex joint in the human body, moving each time we chew, talk or even swallow. Unlike the ball and socket joint of the shoulder or hip, the TM joint is actually a sliding joint, allowing for both rotation, translation and an infinite range of combined movements. The first portion of the opening movement is similar to the way a door opens and closes as if on a hinge (rotation), but a second and longer movement allows the mandible to slide forward and down (translation) to achieve full or maximum opening. To prevent these movements from causing the damage of bone rubbing against bone, there is a disc between the two bones that acts as a cushion to provide protection.

THE TEMPOROMANDIBULAR JOINT

The temporomandibular (jaw or TM) joint is actually two joints. The upper joint is for gliding movements (forward and backward) and the lower joint is for hinge movements (open and close), Note how the relation of the head of the mandible and articular disk to the articular tubercle changes when the mouth closes (a) and opens (b).

Q. I've heard a lot about TMJ. What is it?

A. The TMJ stands for temporomandibular joint. It is the joint between the lower jaw and the skull. It is unique in having a disc between the two bones. This disc can be displaced for many reasons and the joint will not work properly. Sometimes popping and cracking in the joints, pain when opening and closing, headaches, ringing in the ears, muscle pain in the face and neck can be some of the symptoms. There are other symptoms and you should see a professional (dentist or orthodontist! about these. Your dentist or orthodontists should bill through your medical coverage. Insurance coverage for TMJ treatment has not kept pace with the new know­ledge about the disease that has developed in the last few years. It got so bad in 12 states that the legislatures passed laws requiring insurance companies to cover TMJ disorders if they covered diseases of other joints. Check with your medical insurance about your coverage.

Q. Some people with TMJ problems say a chiropractor helped them. Can they really help TMJ?

A. You bet. A number of good chiropractors work with dentists to treat TMJ. The dentist or orthodontist can align the joint and then the bite to where it should be located. Many patients need their necks and spines aligned. I would encourage all dentists to learn to work with chiro­practic professionals.

Temporomandibular Disorders, more commonly known as "TMJ" is a term to describe a jaw joint disorder and the muscles that control the joints. The head, neck and facial pain associated with TMD problems often masquerade as a multitude of other conditions such as sinus headaches, migraines, neck and shoulder stiffness and earaches. Fortunately, it can be treated successfully by a dentist who has the specially required training that is needed to manage these disorders.

The Temporomandibular joints may be the most flexible, yet sophisticated joints in the body because they move up and down, side to side and in a wide range of motion. Muscles attach the bones and joints that allow such movements. Because the nerves and muscles are so complex in this area, when these muscles are in spasm the problems can be far-reaching. It is estimated that as many as one in every four Americans suffer from one or more of these symptoms:

Headaches
Pain behind the eyes
Facial or throat pain
Dizziness
Earaches, congestion or ringing ears
Clenching or grinding teeth
Neck pain or stiffness
Numbness or tingling of the fingers
Click, pop or grating sound in jaw joints
Tired jaws

The primary problem can be in the joints themselves, the muscles of the face and jaw or a combination of these. Because symptoms masquerade as so many other conditions, people travel from doctor to doctor in search of answers for pain relief. Many never think to seek out a dentist who is trained specifically in TMD.

You can observe the action of the jaw joint by placing your fingers on your jaw joints in front of your ears on the sides of your face. Open and close your mouth and you will be able to feel the movement. It should feel smooth without any clicking or popping when opening, closing or moving the jaw from side to side.

Structures that make it possible to open and close your mouth include the bones, joints and muscles. Your teeth are inserted into your jaw-bone. At the other end of your jaw-bone are the TM joints which connect the jaw to the skull. Muscle spasm goes hand-in-hand with displaced jaw joints. Muscles attach both the bones and joints to allow movement to talk, chew, sing, shout and swallow. Any problem which prevents the complex system of muscles, bones and joints from working together in harmony may result in TMD.

There are various ways this system can be disrupted, such as trauma (whiplash) or a blow to the face, connective disorders (arthritis) or skeletal malformation (posture).

Another cause of TMD relates to your teeth and your bite. A "bad bite" prevents your upper and lower teeth coming together in a way that provides the proper bracing support for the jaws. This occurs from a missing tooth, misaligned teeth or back teeth that are too "short".

When this condition is prolonged, the body begins to compensate by involving muscles in other areas; the neck, throat, upper back, arms, fingers and pelvis.

STRESS

Another factor that impacts on TMD is stress. Stress overloads the adaptive capabilities of the jaw. Some people unconsciously grind and/or clench their teeth creating strain on the jaw joints.

MUSCLE SPASM

We all swallow about 2500 times throughout the day and night. The upper and lower teeth must come together firmly each time.

When the bite is unstable, the muscles must work harder than normal causing stress, strain and possibly stiffness. Eventually muscles feel tired and painful. A vicious cycle begins of increased tissue damage, muscle tenderness and pain. The pain makes you feel tense and uptight which worsens the muscle spasm. In turn, this increases the pain.

JAW JOINT DISPLACEMENT

When the jaw joints function properly, the bones do not actually touch because of a thin "disc" of cartilage that rides between them. The disc acts as a cushion and allows the joint to move smoothly. Each disc is held in place by ligaments and guided by muscle. If your bite is not meeting properly, the joint is pulled out of alignment - usually pulling the disc forward. Since the disc no longer serves as a cushion, the joint itself now rubs against the bony socket and presses on pain fibers.

Supplemental treatments and physical medicine modalities that may be suggested include:

Ultrasound
TENS
Physical therapy
Chiropractic
Relaxation therapy
Hot/cold therapy
Nutrition counseling
Spray & stretch
Various injections
Iontophoresis

Because problems associated with the jaw joints can be progressive, accurate and immediate diagnosis and treatment is crucial. Early treatment will help avoid more damage occurring to the jaw joint such as degenerative arthritis. Dependent on your particular TMD problem, treatment may involve several phases.

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