Dediation in Terry Pratchett's The Hogfather

[TracyJ]

I was rereading my Pratchett books and saw the dedication in the front of The Hogfather which thanks somebody for asking the same question as Susan does in the book. The first time I read the book I forgot to keep an eye out for it, and I've just gone and done the same again. Flicking through randomly hasn't come up with anything, so does anybody know what the question is?

[woofgang]

what does the tooth fairy do with the teeth?