What is temporomandibular joint disorder?

Temporomandibular joint disorder (TMD -- sometimes referred to as TMJ) is a pain disorder that occurs in the joints of the jaws, on either side of the face. Specifically, it occurs in the joints located in front of the ears, where the lower jaw joins the face. The pain is usually described as a tension-related ache, though in more advanced stages it can be a sharp pain.