Part of the Skeptiseum's assortment of items relating to the childhood icon, the Tooth Fairy. On either side is a book, at rear a special pillow for placement of the lost tooth, and front left a wooden box for the same. To the right of the box is a mounted coin, "A Sixpence From The Tooth Fairy," which is a commercial souvenir from Austrailia. (For scale, that card is 4 11/16 " square.)
The packaged set, "My Very Own Tooth Fairy Pillow," includes a book, The Story of the Tooth Fairy, and the small (5-inch) pillow, with instructions: "Gently place your tooth in the little tooth pocket and slide it under your pillow. In the morning you will find a surprise. Love, The Tooth Fairy."
The Tooth Fairy legend is prized in American popular culture. It holds that when a child places his or her lost tooth under a pillow, the Tooth Fairy comes in the night to remove the tooth and leave a reimbursement in its place - a coin, a dollar bill, etc. Actually, it is a parent who makes the switch, as a rite-of-passage reward, since a lost tooth represents a stage in a child's growing up.
The practice may have originated in England or Ireland where belief in fairies is prevalent. Some sources believe it may have derived from a medieval supersition in England that a lost tooth must be dropped in a fire to prevent having to search for it following death. (See "Where Did The Tooth Fair Come From?" at Nzgirl.)