What is TMJ?
Almost everyone with jaw pain has heard the acronym. Very few have been told what the joint actually is, or what it does all day.
TMJ stands for temporomandibular joint - the "jaw joint". This joint connects your lower teeth and jaw bone to the skull.
You have two of them, one on each side, sitting just in front of your ears. Put a finger there and open your mouth: the movement you feel is the joint at work.
TMJ stands for temporo mandibular joint. This joint connects your lower teeth and jaw bone to the skull.
The busiest joint you never think about
Your jaw joint moves every time you speak, eat, swallow, yawn or laugh - thousands of times a day, largely without your attention. Unlike a knee or an elbow, it does not simply hinge. It rotates and then slides forward, which is what lets you open wide enough to take a bite.
That extra freedom of movement is exactly what makes it vulnerable. A joint that both hinges and glides depends on a small cushioning disc staying precisely where it should. When it does not, you notice.
Why the term causes confusion
In everyday conversation people say "I have TMJ", but strictly speaking everybody has a TMJ - two, in fact. What they mean is TMJ Dysfunction, the condition in which the joint stops working smoothly.
The distinction matters more than it sounds. Searching for the joint returns anatomy. Searching for the dysfunction returns treatment.
Recognise any of this?
The self-check takes a minute and shows you which of your symptoms trace back to the jaw joint.