Most of us take the ability to open and close our mouths for granted. Therefore, when our ability to do so easily and without pain is compromised, we notice the difference. The joints that control the movements of our mouths are called the temporomandibular joints (or TMJs); these joints connect our jaws to our skulls on both sides of our heads. When one TMJ or both TMJs are damaged or injured—and results in pain while chewing, speaking or swallowing—the condition is known as temporomandibular joint (TMJ) syndrome.