The temporomandibular joint (TMJ) is a small joint located in front of the ear where the skull and lower jaw meet.
It permits the mandible (lower jaw) to move and function.
Anatomy of the TMJ
The jaw joint is unique in that it not only has a hinging motion, but also a forward sliding motion. There is a cartilage-like disk that acts as a cushion to absorb stress and allows the head of the mandible or condyle to move easily within the socket as the mouth opens and closes.
Temporomandibular joint disorders are fairly common, especially in adult females, and have a variety of symptoms. Patients may complain of earaches, headaches, chewing pain, and difficulty opening the mouth. There may also be clicking or grating sounds in the joint.
Possible Causes for TMJ Disorders
Determining the cause of a TMJ problem is critically important. The three broad categories of TMJ disorders are spasm of the jaw muscles, problems with the actual jaw joint structures, and chronic neurologic pain. Many patients have a combination of these problems. A careful history, thorough exam, and computerized imaging will help us arrive at the correct diagnosis.
Muscle pain usually is felt on the entire side of the lower face, and may even extend up toward the ears, temples and side of the scalp, and often worsens after chewing or when it is cold outside. The actual jaw muscles are usually painful to touch, and the jaws may not open as wide due to pain.
Chronic jaw muscle spasm is usually caused by chronic overuse. Some patients clench or grind their teeth. Stress, or even cold weather can also cause muscle shivering and spasm. Missing posterior teeth also place an excessive burden on the jaw muscles and joints and can contribute greatly to TMJ disorders. This is one of the reasons replacing missing teeth is so important.
Problems in the Joint Structures
Pain from the actual TMJ structure is usually felt in the area directly in front of the ears. There is pain to the touch or during motion, and sometimes warmth is felt over the area. There may be clicking, popping, or grating noises, and the jaw may feel locked in an open or closed position.
Temporomandibular joint inflammation may be degenerative arthritis or osteoarthritis, the typical “wear and tear” degeneration that can affect any joint in the body. It may also be an extension of an autoimmune condition such as rheumatoid arthritis. Joint inflammation causes progressive limitation of motion, changes in the fit or occlusion of your teeth, and grating sounds as the smooth joint surface degenerates.
Another type of joint problem involves dislocation of the disk between the jawbone and the socket. A displaced disk may produce clicking or popping sounds, limit jaw movement and cause pain when opening and closing the mouth. After a time, the disk can even develop a perforation or lead to degenerative arthritis of the joint.
Neurologic Pain Disorders
Some pain disorders involving nerve inflammation or injury are unrelated to the teeth or jaws, but the pain mimics TMJ disorders. After other causes have been eliminated, a neurologic disorder might be considered and appropriate medical treatment is needed.
Possible Causes for TMJ Disorders
Conservative, non-surgical treatment is usually the starting point for all TMJ disorders. This may include a non-chewing diet, anti-inflammatory medications, and stopping the offending habits such as gum chewing, nail-biting, chewing hard foods or opening widely. It may also be appropriate to administer bite plate (orthotic splint) therapy. If non-surgical treatment is unsuccessful or if there is clear joint damage, surgery may be indicated.
Surgical treatment usually involves a procedure called arthrocentesis, a minimally-invasive procedure done under sedation in our office. Access is created into the joint and fluids are drained off and replaced with anti-inflammatory steroid medication. Your joint function and range of motion can also be evaluated and improved while you are completely asleep. For more severe cases, arthroscopy can repair damaged tissue by a direct surgical approach. It is rare that more significant joint reconstruction is needed.