TMJ stands for temporomandibular joint, which is the joint that connects the jawbone to the skull. It is located in front of the ear on each side of the head and allows the jaw to move up and down, side to side, and forward and backward. TMJ disorders (TMD) are conditions that affect the jaw joint and surrounding muscles, causing pain, stiffness, and difficulty with jaw movement. Common symptoms of TMJ disorders include jaw pain or tenderness, a clicking or popping sound when opening or closing the mouth, and difficulty chewing or speaking.