To the surprise of some, chiropractic care is a safe and effective treatment for more than just back pain. Temporomandibular joint (TMJ) dysfunction is just one of the many conditions for which chiropractic care can provide relief. The TMJ is one of the most used joints in the body, making it a common culprit of pain and dysfunction.
Anatomy of the TMJ
Located just in front of the ear, the temporomandibular joint is a hinge joint that connects the jaw to the skull. It is the joint responsible for moving the jaw up and down and side-to-side, allowing talking and chewing to occur. The TMJ complex is comprised of many structures, including the mandible (jaw) and temporal bones, the sphenomandibular and lateral ligaments, a joint capsule, the masseter and pterygoid muscles, and an articular disc – a small piece of cartilage between the bones that provides cushioning and permits smooth movement.
Noteworthy aspects of the anatomy in relation to TMJ dysfunction include the bone structure and the articular disc. The mandible has a projection, known as the mandibular condyle, extends into a pit like fossa in the temporal bone. The front of the fossa slants forward and downward to allow opening of the jaw. A bump, called the articular eminence, prevents the jaw from opening too far and dislocating.
While the disc itself is not comprised of any blood vessels or nerves, it continues posteriorly (backward) as retrodiscal tissue that is fully supplied with blood vessels and nerves. This is clinically important, as one of the most common TMJ issues is for the disc to slip anteriorly (forward). When the disc slides or even gets stuck anteriorly, it causes pinching of the nerve-abundant and pain producing retrodiscal tissue.
Temporomandibular Joint Dysfunction (TMJD): Pathophysiology
With so many structures involved, there are multiple presentations of TMJD. The most common presentation is caused by anterior slippage of the articular disc. In a healthy joint, the mouth opens as the jawbone rotates then moves forward and downward before reaching the articular eminence. Normally, the disc sits atop the mandibular condyle and moves along with it. In TMJD, the disc slips forward, in front of the condyle, and pulls the retrodiscal tissue into its spot between the two bones. Since this tissue is innervated, the pressure of the two bones creates pain. With the disc in front of the condyle, it becomes an obstacle to opening the mouth. In order to open, the condyle has to “jump” over the disc, causing a pop or click.
In late stages of disc dislocation, the condyle is unable to jump over the slipped disc, eliminating the pop/click but creating decreased range of motion, as the condyle is stuck behind the disc. In this case, the jaw is considered “locked”. In some cases, the jaw will adapt by scarring retrodiscal tissue, creating a pseudodisc. With the creation of scar tissue, the pain related to TMJD can be reduced.
Another form of TMJD involves joint degeneration. As mentioned before, the TMJ is one of the most used joints in the body. As the joint is used over and over again, stress is placed on the articular disc and it begins to wear thin. While this is a progressive issue, there are treatment methods - both in the office and at home - that can slow any advancement of damage.
Many times, stress can lead to the symptoms of TMJD. Bruxism, or teeth grinding, and jaw clinching can be a physical manifestation of emotional and mental stress. This results in tight and tender muscles and jaw pain.
Whatever the pathology, TMJD can cause any of the following problems:
- jaw problems, including pain, locking, clenching/grinding, and clicking/popping
- teeth issues, including sensitivity and chipped teeth
- headaches, including tension, migraine, and sinus type
- ear issues, including tinnitus, clogged ears, dizziness, and vertigo
- swallowing difficulties
- eye issues, including blurred vision and light sensitivity.
Chiropractic Care and TMJ Dysfunction
So, how can chiropractic care help reduce the symptoms and relieve TMJD? Tune in next time for Part II.