Hi, I have something similar, a subluxing shoulder joint, which isn't a connective tissue disorder, but causes the same kind of symptoms. I find that when my shoulder is worse, i guard it, which causes my back to hurt and my neck to also hurt. This is just an idea but maybe because your jaw is hurting, you have adapted the way you use it to be less painful but this is causing other muscles and things to work for it, and therefore hurting them too. I think it is called posture guarding.
Hope you are feeling a bit better
Jenni
Hope you are feeling a bit better
Jenni