Alphadeus

My son did the same thing yesterday, sounds painful

I had a similar issue for a long time with my inner cheek. The space in my mouth is apparently kinda small for the size of my teeth so I used to scrape them with my wisdom teeth, which would make them swollen which in turn made it easier to scrape them.

Anyway long story short I eventually had to go to a dental surgeon to get all 4 wisdom teeth removed at the same time. Also as an extra fun fact, I need to use childrens toothbrushes because the heads in adult ones are too big for inside mouth. THAT'S how little space there is.