I have advocated keeping all the teeth you are able to. Eating problems are made worse by having no teeth. Joanna has given good advice; seek dental advice from someone very familiar with radiation and don't let them take teeth without very good reason!
I still have every one of my teeth including wisdom teeth (of course you know why

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I think it is good they are looking at a possible tonsillectomy as well. My tonsil cancer was not visable during the usual visual exam, even though it had spread to 3 nodes.
I pray for your speedy recovery!