I Have No Wisdom Teeth According To The Dentist I

I have no wisdom teeth according to the dentist I visited a month ago well the past few days I've had a weird irritation behind my bottom back molars... Took a flashlight today and noticed that it appears a patch of skin is gone on one side with appears to be dead tissue around it like a blister of sorts. The right sight kinda has the tissue and is nowhere near as big as the left but I also noticed a couple very small red dots that almost look like blood spots on the side of my cheek. I don't think it's cancer or anything due to the fact they aren't really a patch it's a few that line the back of my cheek