I had the same problem with my TMJ. I would clench my jaw and grind my teeth while sleeping. This caused a chain reaction where my sinuses would become overly stimulated and I would have extreme drainage, leading to the enlargement of my neck glands and tonsils.
Strangely enough, I found that changing to a different pillow with better neck support, keeping my chin up and my head back, did more to alleviate the jaw clenching and teeth grinding than anything else I had tried. I also hold a second pillow in my arms with it resting just under my chin to help with the neck position as well.