Hello there & welcome!
I have myofacial dysfunction as well. It's very painful to say the least. In the meantime before you get your biteplate, try making sure you sleep on your back, it's harder to clench or grind your teeth in that position.
I would also try to make sure you stay on a soft, no chew diet. It will help the muscles in your face relax some...no singing, yelling, or talking loud either. This tends to aggrevate the muscles as well.
Heat and ice alternately will help with discomfort. (Heat for the muscles spasms and ice for the nerve spasms) You'll have to judge which feels better for you.
As for the mouthguard substitute, you might want to try the football type of mouthguard you can get at sporting goods stores. You boil it to make it fit the shape of your teeth. They are usually a little uncomfortable and I can usually chew through them in a few nights, but they will work in pinch.
Good luck and hope this helps a little!
Jennifer
[This message has been edited by OHJELJ (edited 03-20-2003).]