Does anyone know....

That's a really good question. I don't know either but I'm going to go see if I can find it online somewhere. I'll let you know if I come up with the answer. Until then I wanted to share this with you. When our daughter was about 5 she asked us what the tooth fairy did with all the teeth. I was stumped but my wonderful husband came up with this answer without missing a beat. It was as if he has always known this to be the truth. lol He said, "the tooth fairy takes your baby teeth and polishes them and cleans them and then gives them to the new babies who need their baby teeth." I had to hold myself from laughing so that she would accept this. But I as so amazed.

Sorry if it is not so close to your topic, but interesting ideas about tooth fairies (and not only about them) you can read in fantasy book Hogfather by Terry Pratchett. Well, tooth fairies aren't the main theme in that story, but you'll find it quite amusing, if not interesting. Terry Pratchett's books are very funny and wise at the same time. Just wanted to give tip to good books :o)