Oh geez, there's a couple to explain here.
1.) I once had an extreme pain in my side. When the doctors did their scans and what not, they saw I had a abnormally sized appendix, so they gave me an appendectomy thinking that it was appendicitis. Turns out it was pneumonia and I just had a large appendix. Who needs it anyway?
2.) A couple of my infant teeth had their roots wrapped around the adult ones underneath, and refused to come out. So, I had removed the two of them removed so the orthodontists could move forward in straightening my teeth.
3.) My tonsils were giving me a lot of trouble with sleep apnea, so my parents had them removed because they were worried. I know that seems a bit extreme but I would wake up gasping for air due to suffocation.
4.) This is the one that had the most effect on my life. When I was a few months old, some extra blood vessels started growing on my forehead. They had hoped it would swell down, but it had gotten to the point where I had a golf-ball sized blood red lump on my forehead that was only getting bigger. The doctor's said that it'd eventually go back down on its own, but not without fucking up my hairline, my eyes, and leaving me pretty much disfigured. So they had it removed. What's left of it is a zig-zag shaped scar on my forehead, which has been the cause for much Harry Potter teasing in my lifetime (however I was born before the first publication, so suck it JK Rowling!) however looking back at the possible alternative some teasing isn't so bad. So I guess you would call that some form of plastic surgery (?) anywho, that's all from me.