What does the tooth fairy pay for a tooth?

In Italy also the tooth fairy (fatina) is often substituted by a small mouse (topino). Tooth traditions in different parts of the world have been collected together in the excellent children's book Throw your tooth on the roof: tooth traditions from around the world written by Selby Beeler and illustrated by G. Brian Karas (Houghton Mifflin, 1998).

Typically, upon losing a tooth the child places the tooth under his or her pillow before going to sleep. In the morning the child finds a coin, small banknote, or a present in the place of the tooth. In reality, this is usually done by the child's parents.

A less-common variant is for the child to place the tooth in a glass of water beside the bed. Again, in the morning, the tooth is replaced with a coin. This variant is becoming more common, as it is far easier for parents to find a tooth in a glass of water beside the bed without waking the child than it is to search under the pillow.

The primary useful purpose of the tooth-fairy myth is probably to give children a small reward and something to look forward to when they lose a tooth, a process which they might otherwise find worrisome. It is fun for both parent and child. It also gives children a reason to give up a part of themselves that they may have grown attached to.