young man with jaw painWhen the RDC-TMD Consortium announced its new diagnostic criteria, which have been embraced by the American Dental Association (ADA), it moved us a long way toward having good definitions of different TMJ conditions. But it didn’t necessarily clear things up for many people who may still wonder what some of the terms mean. If you have been diagnosed with TMJ, your doctor will explain in detail what your diagnosis means, but if you haven’t yet been diagnosed, you may still be unclear about the different categories of joint problems that are included in TMJ.

Here is a brief description of these conditions, along with some description of symptoms. It’s worth noting that not everyone who has disc displacement gets symptoms, and often the symptoms do not correspond with the disc displacement you have.

Disc Displacement with Reduction

Disc displacement, sometimes called internal derangement, is when the cushioning disc between your jaw and your skull has become displaced. This can result in jaw pain, but it doesn’t always.

Typically, your jaw will first experience disc displacement with reduction. This means that although the disc is displaced, it’s still somewhat between the bones, and when you open your jaw it gets squished–compressed or reduced. As the disc moves in and out of place, you may experience a popping or clicking sound.

Some people with reduction will experience locking–the disc gets in a position where you can’t open your jaw. You can typically maneuver your jaw one way or another to get it back into place and open your jaw successfully.

Disc Displacement without Reduction

When this occurs, your disc is so far out of place that it doesn’t get compressed any more. Instead, it maneuvers into a place where it may block your jaw from opening. When this occurs, you can’t do anything on your own to get the jaw to open.

Degenerative Joint Disease

Degenerative joint disease describes a condition where the joint disc and other tissues have degraded and are no longer capable of providing cushioning of the joint. This may be related to disc displacement or it may occur for other reasons. You may hear popping and clicking, as well as crepitus–the grinding sound of bones rubbing together.


In subluxation, both the disc and the round, bony part of the jaw that fits into the joint–called the condyle–have popped out of place. Your jaw may seem to stick open sometimes, but you can usually wiggle your jaw one way or another to get it to close. Without treatment, this may progress to luxation, when your jaw sticks open but doesn’t respond to movements.

What Is the Problem with Your Jaw?

Although these conditions may seem clear-cut on the screen, when it comes to diagnosing them, it’s a lot more complicated. But if you want to get relief from jaw pain and related symptoms, it’s crucial to determine what’s the actual condition of your jaw. To get a diagnosis of your jaw problem, please call (303) 691-0267 for an appointment at the TMJ Therapy and Sleep Center of Colorado in Denver.