That stands for tempomandibular joint (if I remember correctly). It means the hinges that allow your
jaw to open. The hinges are right next
to your ears. If you touch or manipulate the bad side, does it hurt there? Your dentist can confirm whether or not you have this disorder.
It's not usually part of MS, but it can be. I had a lot of trouble there for several months in '06, but it finally abated and has not retuned.