Hi Carla,
Marion might have hit the nail on the head so to speak. When I get stressed, which is a lot most days, I grind my teeth at night. I'll wake up in the morning and my jaw will really be hurting. Well it did before I started sleeping with a night guard. It's kind of like those mouth guards that sports people wear, except it's really thin. I got it from my dentist.
Oh I just thought of something...it looks exactly like one of those invisalign braces they advertise on TV. In fact I think it's the same thing. Anyway get you one of those and see if it helps. Mine was kind of expensive because it came from the dentist, but I'm pretty sure I saw the same thing in Walmart one day in the dental aisle.
Hope that helps,
xoxo
Lexxi