When I was 15 I had to have my last 3 baby teeth pulled. It was extremely unpleasant since they all shattered in my mouth and I got to experience for the first time that a ridiculously fast metabolism means you burn through anesthesia quick enough to need two follow up injections during the procedure. One of my adult teeth had started to disintegrate under the baby tooth and when it suddenly had a space to fill got very confused, which resulted in it coming in backwards. Unless you'r a dentist staring in my mouth, it's pretty much impossible to discern, but if you're in the profession it's apparently really funny. There have been visits where I've had four doctors pointing out how it's rotated 180 degrees and laughing.
Last week I had a dentist appointment and they took new x-rays with a new machine and discovered that I have a shard of baby tooth still in my mouth. The dentist assured me it's just making my surrounding adult teeth stronger, but I guess now I have two weird tooth quirks to bring up in awkward social situations. :P