Temporomandibular joint and muscles disorders, commonly called “TMJ,” are a group of conditions that cause pain and dysfunction in the jaw joint and muscles that control jaw movement. 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. 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, and discs and bones from working properly may result in a painful TMJ disorder.