Around the same time, a professor at nearby Northwestern University Dental School named Rosemary Wells found herself similarly baffled. After all, the ritual of children placing their shed baby teeth under their pillows, in the hopes of finding them replaced with cash in the morning, was already being practiced by millions of young Americans. These kids left notes for the tooth fairy, and believed they shared personal relationships with her that spanned several years (and up to 20 baby teeth). How was it possible, Wells wondered, that nobody knew where she came from