Temporomandibular joints (commonly abbreviated as TMJ) are the ball and socket joints that connect the upper and lower jaws to the temporal bones of the skull. Everyone has them and they can be found, on each side of the head, just in front of the ear. These joints are critical for our ability to move the jaw up and down, side to side, and back and forth. The temporomandibular joint motions are necessary for normal functions like chewing, making facial expressions, yawning, breathing, and even speaking. In each TMJ, there is a small circle of cartilage that serves a cushion for your jaw as it moves, preventing your jawbone from rubbing against your skull. You can locate your TMJ joints by placing a finger in front of each ear and opening and closing your jaw. If your TMJs are in good condition, your jaw muscles will move your jaw smoothly up and down, back and forth, and side to side.