I did HBO for ORN and my issue resolved. I was also trying other therapies/meds etc so it was only a part of my treatment but it seemed to help me. It is controversial I guess, whatever that means- I'm curious about docs that refer to it this way. It's fine if they want you to have all the facts but it can sometimes come off like they're trying to talk you out of it. I had to fight for it. It's expensive.

Having a good dentist is essential post radiation. From what you're saying it sounds like your dad has about four teeth left? Is that correct? I'm no expert but I definitely agree with this:

"have a general dentist look things over to see if any teeth can be saved before having teeth removed."

Amen to that, especially if he's down to four.