Resource: ADA
The temporomandibular joints, called TMJ, are the joints and jaw muscles that make it possible to open and close your mouth.
Located on each side of the head, your TMJ work together when you chew, speak or swallow and include muscles and ligaments as well as the jaw bone. They also control the lower jaw (mandible) as it moves forward, backward and side to side.
Each TMJ has a disc between the ball and socket. The disc cushions the load while enabling the jaw to open widely and rotate or glide. Any problem that prevents this complex system of muscles, ligaments, discs and bones from working properly may result in a painful TMJ disorder also known as TMD.