Temporomandibular joint syndrome, or TMJ syndrome, is a dysfunction in the jaw joint on either or both sides of the jaw up by the ear. The mandible (jaw bone) attaches to the skull at the temporal bones (cheek bones). At the junction of these two bones there is a soft fibrous disc that helps to guide movement and reduce stress. Surrounding the joint is a ligamentous capsule that helps to keep the joint in place. The muscles that move this joint include the masseter and temporalis which are the jaw closing muscles; infrahyoids and suprahyoids which are groups of muscles in the front of the neck that open the jaw; and the lateral pterygoid and medial pterygoid that are mostly responsible for side to side movement. Some of these muscles also produce protrusion and retraction of the jaw (chin forward and backward positions). In reality, it is actually the combination of all of these muscles working together in the correct firing pattern that produces all the jaw movements, but this is too complicated to address here.
There are three basic dysfunctions that cause temporomandibular joint pain.
1. Compression of the TMJ
2. Stretching of the TMJ
3. Myofascial problems in the muscles around the TMJ
It is possible for more than one of these issues to occur at a time.
Compression of the TMJ can occur creating damage to the TMJ disc. This can cause warping, displacement, or just plain old irritation. If compression creates pain, then this is likely the problem, and the diagnosis is synovitis.
If distracting or stretching of the TMJ causes pain, then it is likely the capsule that is irritated. Remember that the capsule is a set of fibrous ligaments surrounding the joint and is important for keeping the joint in place. If stretching causes pain, the diagnosis is usually capsulitis.
Sometimes the muscles around the joint can become dysfunctional. They can become hypertonic, tight, and tender. This is usually a result of a postural abnormality that causes the muscles to have to work harder than normal. If the muscles are the cause, then the diagnosis is myofascial pathology.
When a patient presents with TMJ complaints, one of the first things I look for is whether proper occlusion occurs… that is… does the mouth shut properly. Do the teeth all fit into each other when the mouth is closed, and is the closed position in a comfortable resting position for that TM joint? If occlusion occurs in a position that protracts the jaw backwards or forwards or left or right, then this can stress the TMJ. Problems with occlusion are common, and it takes a dentist or orthodontist to tackle this part of the problem. Therefore, I feel it is important for Chiropractors to cooperate with these professionals in a team effort to treat TMJ syndrome.
Another thing I look for is the quality of motion when opening/closing the mouth. Many people with TMJ syndrome will not actually open and close in a straight path, but rather deviate left or right slightly in a C-shaped pattern. This indicates that there may be an imbalance in the musculature, specifically the pterygoids.
I also look for a combination of clicking, popping and/or locking of the jaw. Any of these can occur when opening, closing, or both and can shed some light onto the mechanism of dysfunction in TMJ syndrome.
Treatment for TMJ depends on the diagnosis. Adjustment of the TMJ may not be warranted. Correcting the posture of the head and neck is usually very helpful and therefore adjustment of the neck and upper back may actually be more beneficial than adjusting the TMJ itself. Myofascial release or trigger point therapy (soft tissue techniques) are necessary if the problem is myofascial in nature. Stretches and exercises for the jaw, head, and neck are usually a big part of treatment as well.
If you have pain in your jaw when chewing or talking, or if your jaw clicks/pops/locks, then please seek the help of a qualified physician like a Chiropractor.