Temporomandicular joint dysfunction (TMD) is a condition involving facial pain involving one or both sides of the jaw. TMD can also be associated with neck pain, ear pain, and headaches. It is an all encompassing term for jaw or facial pain including specific jaw joint pain or pain due to overload of the muscles surrounding the joint. Jaw pain is a unique situation in physical therapy as it is often difficult to think of our jaw as we would any other joint in the body. The jaw is often overlooked as a cause of pain in the facial and cranial regions with patients often experiencing pain over a prolonged period of time. TMD can be linked to a tricky recovery as the diagnosis is general and lacks a true treatment pathway without an in depth exam uncovering functional impairments that lead to pain.
From a physical therapy standpoint a patient arriving with a previously established diagnosis of TMD will be evaluated in regard to their jaw as well as the cervical spine. This is due to a close relationship in cervical spine posture and jaw function. A quick example of this can be completed by altering your own posture. Try to sit up extremely tall, (in perfect posture!) and click your teeth together softly. Now slump forward and push your chin out forward, click the teeth together again. Your teeth may have approximated in a different position based on your changing your, this is a direct example of how our posture can affect our jaw function.
TMD, and jaw pain by association, can be caused by differing sources of pain including the jaw itself (intra-articular pain) and the surrounding musculature and joints (extra-articular pain). These sources of pain alert the nervous system to potential damage leading to stimulus to the portion of the brain that is responsible facial sensation. This often leads to confusion in the brain as to what the source of the pain is, and can lead to generalized facial pain, sharp jaw pain, ear pain, headache, any or all of the above.
A short explanation of the various causes:
Intra-articular:
Disc derangement: the temporomandibular joint is composed of a stable joint surface and a movable joint surface, between the two is a small disc that buffers and aides motion of the jaw. If the disc does not move properly it can be a hindrance to movement and be the cause of clicking and popping in the jaw. If the disc holds, holds, hoooolds..then moves quickly into its proper position this can cause an audible pop. If the disc holds, holds, hoooolds and does not slide there is no click or pop, but the jaw will move significantly less. This are called reducing and non reducing disc conditions.
Inflammation: The actual jaw joint tissue or tissue associated with the previously mentioned disc become inflamed and can be pain generating sources
Degeneration: jaw joint surface degeneration or degeneration of the disc tissue lead to a more grinding presentation rather than clicking and can contribute to dysfunction.
Joint hypermobility or hypomobility: In hypermobility the jaw joint moves in excess and with less stability leading to uncontrolled movement that is in need of stabilization and coordination. In hypomobility (capsular restriction) the jaw joint is stiff leading to less mobility on one or both sides of the jaw, manual therapy and jaw exercises can improve mobility.
Extra-articular
Postural dysfunction: Changes in standing and seated postures can result in interruption of proper jaw function. Think back to our teeth clicking example.
Muscular Imbalance: imbalance between the opening muscles of the jaw and the masticating muscles of the jaw result in improper function of the jaw joint itself.
Treatment of TMD by a physical therapist is supported by medical research showing gains in ability to open the jaw and mouth and reduction in pain associated with TMD. Manual therapy provided by a physical therapist can provide the proper treatment path to improve your quality of life by allowing you to return to pain free daily function. This can be a wide range of activities when talking about a unique joint such as the TMJ. Improved quality of life may be as simple as being able to yawn without pain, open your mouth wide enough to enjoy your favorite sandwich, or be able to sleep in your favorite position.
Evaluation, education, and proper one on one treatment are important in any rehabilitation and with TMD the analysis offered with one on one treatment becomes even more important. Facial pain can be caused by any number of conditions that are in need of further investigation and care outside of the physical therapy clinic.
Jaw pain is common, though it is not a normal occurrence. You should be able to enjoy a quality of life that is not interrupted by jaw and facial pain. Visit our website for further education or to contact our office with any questions!
Dr. Nicholas Smith
(previously posted by the same author)