Same thing happened to me, my teeth were always perfectly straight and I never had any cavities, but one day I went to the dentist and she said "you know you still have a baby tooth right?"
I was like WTF? I just thought it was smaller and cute

The adult one never came out the side or anything like that, it just didnt move out of my jaw at all. It was my right upper fang. So they had to cut through my upper pallet and removed a chunk of it, about 2cm x 2cm, and attached wires up inside that would slowly pull the tooth down into position. They covered the hole in some weird gum like thing to stop it from healing over.
It was fucking painful! The meds were great though
This was years ago though, all good now. Still dont smile though hahah