I finished my Radiation on 7/10. (no Chemo). My Oncologist told me my worst day would be a week after my Radiation. I had intermittent pain in my jaw a few times a week during my 33 treatments. It started after the 3rd week. I was told that it was normal & was caused by 'excited' nerves. Day 7 after trearment was indeed my worst day of this cancer. I was very nauseous & fatigued. My jaw still bothers me & my teeth & gums are very sore. I have been able to control pain with hydrocodone but I don't want to take it any longer than I have too. I am hoping this too shal pass with time. Best of luck to your father.