D-
My husband is going through the same thing as your mom...13 weeks after receiving 7 weeks radiation combined with 6 chemo treatments.

I asked this question on the forum section about medications/treatments...if you check there some of the survivors have given me some good advise. They did mention that the "burning" is often a symptom of "thrush" and that it doesn't "look" like most doctors expect it to look, so it is often not diagnosed properly. We had the doctor prescribe Nystatin- antifungal mouthwash just as a precaution yesterday- it can't hurt. Maybe this can help your mom also. The doctors kept telling us it wasn't thrush but I guess that is what they told all the others as well, but the medication helped...one survivor received relief from the burning one day after using the Nystatin.

I hope this helps, I know from a caregiver's point of view that this is frustrating for everyone, not just the patient.

Keep your spirits up...I've found this site to give much needed encouragement.

Lorie