I must disagree with the poster who says they haven't done TMJ surgery for years. I had some done 2 years ago and know several people who have had successful surgery done within the last couple of years. It is not the same surgery that used to be done and is less invasive and less painful. I had disk repositioning done and it has helped considerably. I still have some problems and still wear my bite plate at night because I clench my jaw.
Prior to the surgery, the migraines were debilitating and I could barely open my mouth. Now, I am so much better. Rare migraines, I can talk just fine and it is the rare occassion (considerable stress usually) that makes me grab the moist heat pack. I have changed alot of my habits and that has also helped - no pillow under my head for sleeping, just a towel under my neck, sleeping on my back with a pillow under my knees, pressure point massage of my jaw and neck that I've learned to do myself, physical therapy to keep me in order when I'm stressed. I fortunately have good insurance to help with the PT. My bite plate was covered by my insurance, but my surgeon told me I could also use the ones that Walgreens carriesthat you boil and form to your mouth.
Check out this site for more info on surgery. Not everyone needs surgery, but when all else fails it is still a viable option.
http://www.mayoclinic.org/tmj/treatment.html