jim,
i'm so sorry you've had to go through all that! i didn't go through nearly what you did, but i have experienced some mouth pain on the left side (the side that was targeted by the radiation). the salivary glands on the left side will most likely never come back so it makes that side of my mouth and the mucosa very, very dry. that dryness causes friction against my teeth which then causes the pain. i found that if i swish with water a lot and use a mild mouthwash several times a day (ACT or Biotene) then the friction isn't so bad. i am still trying to come to terms with the fact that this may be a problem i will have to deal with for the rest of my life. it is very difficult for me to accept the 'new normal'. i hope this helps and wish you the best.