I have been finished surgery for 23 mos and rads for 20. In that time I've had 2 ulcerations on the opposite side of my original tumor. (My real tongue - not the rebuilt area. I have a crossbite and high arch so my tongue when swollen, even when not tends to rub on my teeth - hence causing irritation. My first ulceration took 2 months to heal. The second a month. With a normal person who's never had rash it would have taken a week. Compromised healing is very possible, and continued irritation to the area (acidic foods - rough foods) can all make that take even longer. The medication my dr gave me (oracort) said to apply it at bed time. I did this for two weeks with only minimal healing. What really solved the problem was going back to a soft bland diet, and rinsing and applying the med right after I'd eaten anything. Then after 2 weeks it was gone. The second ulcer I'm certain was directly related to rubbing on molars - I went to the dentist had the two culprits filed down to a softer rounded edge, and then did the same thing diet, and med wise. And the second one is now gone. Freaks me out every time - definitely have it checked and keep a close eye on it but its likely from rads etc...