Sometimes referred to as: temporomandibular joint dysfunction, TMD (temporomandibular disorder)
The temporomandibular joint is the joint of the jaw, the hinge that connects the jaw to the skull. The name comes from “temporo-,” referring to the temporal bones on the sides of the skull, and “-mandibular” which is the medical term for the lower half of the jaw. The temporomandibular joint is supported and stabilized by several muscle groups. It is the joint that allows you to open and close your mouth, eat, talk, and make facial expressions.
Cases Per Year (US)
TMJ is very common, with approximately 35 million people affected each year.
Affects up to 15% of adults (some studies estimate a prevalence as high as 25%). But at most, only half will seek treatment.
TMJ, especially when chronic, can significantly affect quality of life, with a significant financial burden from lost work days.
What causes TMJ?
There are various causes of TMJ. Jaw muscle tightness or spasm is a common cause. Teeth grinding (“bruxism”) is often the culprit, as this overworks the jaw muscles. Many people grind their teeth at night without being aware of it, and may wake up with noticeable tightness or soreness of the jaw muscles or teeth.
True joint disorders cause a minority of TMJ cases. This category would include arthritic joints in osteoarthritis, inflamed joints in rheumatoid arthritis, or loose/hypermobile joints in certain genetic connective tissue disorders.
Poor head and neck posture may contribute to TMJ, due to dysfunction or suboptimal alignment of the muscles connecting the head, neck, and jaw. Issues with the neck, most commonly instability or hypermobility of the cervical spine, may also play a role.
Finally, injury or trauma to the joint may set off or exacerbate TMJ.
In all of these cases, the way in which the brain processes pain signals from the head and body can be a contributing factor. In some people, the nerves may continue to transmit pain messages to the brain even after an initial injury has healed.
Connect with our physicians
Joanna Mandell, MD and Nora Lansen, MD are both members of the Galileo Clinical Team. Connect with one of our physicians about TMJ or any of the many other conditions we treat.Join Today