Anatomy of the TMJ

(temporomandibular joint)

The jaw joint is located where the lower jaw (mandible) connects to the skull (temporal bone), directly in front of each ear and is called the TMJ. TMJ stands for the Temporal bone, the Mandible and the Joint where they meet. The TM joints are a "ball and socket" joint and provide for both a hinging and gliding movement. These joints are a part of a group of muscles, ligaments and bones that work together to allow for talking, chewing, etc. 

 

Inside the TM joint is a disk, which acts like a "cushion" and separates the temporal bone from direct contact with the mandible. The disk provides gliding action between the upper and lower jaw when opening and closing. The condyle is the round or ball portion of the lower jaw (mandible) and slides in and out of the socket, or fossa. Attached from the disk to the back of the joint is connective tissue, which contains blood vessels and nerves. Movement of the joint is lubricated by synovial fluid. 

Open view - normal disc position

Open view - abnormal disc position