TMJ and TMD Definition
TMJ is an abreviation for Temporomandibular Joint which is the joint that attaches our lower jaw to our cranium and allows us to open and close our mouth. "I have TMJ" is a common way of saying that I have problems with my Temporomandibular joint.
TMD is a little more correct but less commonly used and meands Temporomandibular disorder or dysfunction.
Signs of TMJ or TMD Problems
Popping or clicking noises is one of the most common signs, tenderness or pain in the area in front of the ears, difficulty opening or closing the mouth, ringing in the ear, pain mimicking ear pain, tenderness in the muscles of mastication, headaches, all these are signs that could appear in TMJ disorders.
Treatment usually starts conservatively with some intraoral appliances, and if these are successful in eliminating the problem then Orthodontics might be considered to be able to stop using the removable appliances. Your dentist is commonly able to do a screening for TMJ disorders and make a recommendation that is appropiate to your particular situation.