Stages of TMJ Dysfunction - Videos of the TMJ Anatomy

Here are the stages of the TMJ Dysfunction:

Normal Temporomandibular Joint (TMJ):

Notice the bi-concave shape of the disc, and it consistently stays between the condylar head and the articular eminence.  When the mandible is closed, note that the joint is more down and forward as opposed to up and back, leaving room for the blood vessels and nerves posteriorly.

Anterior Disc Displacement With Reduction (Disc is sitting in front -anterior to the joint head and reduces, or moves back to the normal position upon opening)

In this case, you can see that the ligaments are more stretched out, leaving the disc anteriorly displaced on the joint, so that when the jaw opens, it 'clicks' or 'pops' back in place, and a second 'click' occurs during closing.

Medio-laterally displaced disc of TMJ Dysfunction (disc moves toward mid-line and re-appears as it moves laterally toward side of face)

In this example of TMJ Dysfunction, the disc displaces (moves out of position) and reduces (moves back into the proper position) medio-laterally.

Degenerative Joint Disease with Perforation (ligament and/or joint tear)

This shows when the last stage of TMJ Dysfunction where the disc is perforated and thus positioned completely in front of the condyle.  There is no longer that bi-concave shape, and you can notice the flattening of the condyle (head)  due to the continuous bony tissue contact with adjacent bony cavity.  Note also how the shape of the cavity has changed (it used to be round, now has flattened).

This example shows a Disc Displacement withOUT reduction, or Chronic DD. Note the disc is stuck in front of the condyle and cannot recapture or reduce.