Hi there,
I don't have RSD in my face but ever since I was diagnosed with RSD I have been getting problems with my teeth and I also get a sharp pain in my gums. Many of my teeth are chipped, I believe that the medications cause this to happen.
I find it hard to eat because of the problems, I have to eat on one side of my mouth. I don't get neck pain
Please speak to your PM doctor about this, he will be able to look in your mouth/neck to see what it is.
Take care
Love
Alison