When I was little I was told that the tooth fairy recycled teeth, which is why they had to be clean and cavitiy free for her to leave you any money for them. This belief was reaffirmed when I lost one of my upper front teeth and less than a week later my baby cousin cut the exact tooth that I had lost. I've passed that belief on to my kids.
A childhood belief about fairies

others believed things like this
- I used to think that the tooth fairy puts you in a deep sleep before stealing your tooth/teeth.Anon
- I used to believe that in the tooth fairy took all your teeth and built a tooth city for her to live in!Anon
- My mother told me that the tooth fairy would only come if I brushed my teeth.— Dale
- I used to believe the the tooth fairy was a Pokemon fan because she got me Pokemon Crystal for my lost tooth— Pokemon fan
- As a child I was taught that the tooth fairy would buy our teeth so she could add them to her crown.— Lola
- That the tooth fairy drove around in her green Volks Wagon Collecting teeth from all the children.— Wanda Trytten