I suffer from the same thing and the dentist says it's teeth grinding. She has made me a rubber guard to wear over my teeth at night .I'm really struggling to wear it though as soon as my head touches the pillow I start to gag . I am trying to preserve to get rid of the jaw pain .

I have a dead tooth and can sometimes be painful. Saw a specialist and he said to take anti inflammatories as there was no infection so definitely linked to the fibro.

Margaret, there are different kinds of night guards. I didn't like the first one I had either. Maybe another kind of night guard or just having to get used to it? Wishing you good things

Is it possible you're grinding your teeth at night?

I very often get this, bur as you say dentist says all ok x