Temporomandibular dysfunction (TMD) is a condition of the of the jaw muscles, temporomandibular joints, and nerves commonly associated with chronic facial pain. The temporomandibular joint (TMJ) is located in front of your ear. It’s where the temporal bones and mandible (lower jaw) come together. We are born with two temporomandibular joints, one on each side of our skull. Because of the position of these joints, TMD commonly causes pain in the lower jaw, face, neck and back.