WZ,

You have had quite a hard road through the surgery and radiation. And it sounds as if you were/are seeing docs frequently. I'd phone the ENT again and get in to see him. Maybe it is an infection, maybe the benefits of the oxygen wear off (I know nothing about that)

But, it is most important that you feel comfortable and having your ENT look in your mouth and at your incisions will go a long way to your comfort level.

Maybe tonight some more people that have had similar symptoms will be on the board.

Good luck,
Dinah