I have had both a flat splint and a grooved splint. I found that with the flat splint, my jaw joint seemed to ache more than with the grooved splint. However, the grooved one would result in headaches and sore muscles, but less jaw joint pain. I found that I have to alternate them for the least pain, until I can speak with my surgeon tomorrow. It makes sense to me though, and I plan on discussing my theories with the Dr.
I had a hard flat splint (of the $600 range) made by a crappy TMJ doc, that my good TMJ doc had been grinding down so that my teeth would all hit at the same time...well, between him grinding it during visits and me grinding it at night, I wore through it and have to wear my old cheaper splints ($200) - the flat and the groovy. I also found that when I woke up in the AM my teeth hit evenly, but by the time I got to his office (1 hr away) my bite would be off, whether I ate or not. I also found I could stretch the jaw muscles on the tight side by placing a q-tip between the molars and manually closing the opposite side. Sometimes it was painful, sometimes not, but it always helped me in the end. This also is a good excuse to eat gummy bears (gummy bear in place of a q-tip)

. Anyway, different things work for different people. I will let everyone know what happens. I wish I had found this board when this all started, I would not have let the popping and grinding go so long if I had known the consequences. Have a great day! -Gabi