War criminal tooth fairies did that, in the second world war, for gold teeth.

I like Pratchett’s take. The Tooth Fairy of the Discworld takes the baby teeth and hides them in his domain because pieces of a person can be used for sympathetic magic, like cursing someone, and he wants to protect the kids from that.

Just say they’re banned from graveyards, because they pulled that shit all the time without burying them again. You need to stay consistent and plausible with those lies. 😉

The people are only dead because they refused to keep giving the Tooth Fairy their teeth, so (s)he killed them but will honor their wish in death.