When Madeline Hanstad's first loose tooth was barely hanging on, the questionable honor of breaking it free fell to her dad, Josh. "One, two, three," he said before he pulled. The Apple Valley child was fine — until she saw the tooth sitting in his hand. Then she started to cry.

"I think that feeling, when you lose the tooth, was just weird to her," said her mother, Christen Hanstad.

The thought of a visit from the tooth fairy cheered her up, though. Like other 6- and 7-year-olds across the country, she placed her tooth under her pillow and waited with anticipation for the tooth fairy to leave her something special.

The loss of one's baby teeth can be seen as a rite of passage, said Melissa Koenig, an associate professor at the University of Minnesota's Institute for Child Development. This milestone in some ways symbolizes the loss of childhood. Our current tooth-fairy tradition may have evolved in the United States as a way for children and their parents to give expression to this loss.

The tooth-fairy ritual reassures children during a sometimes frightening time, and also empowers them. The typically monetary nature of the exchange signifies independence, Koenig said. The ritual also allows parents to bid farewell more slowly to the belief in fantasy creatures that characterizes early childhood.

"While the children are getting the independence they need from the ritual, the parents are seeing their children engage in something childlike," she said. "And that helps them slowly give up the reins in a way."

A long history

Our tooth-fairy tradition probably was influenced by an older European custom of burying baby teeth in the ground in the belief that this would help new ones grow. But many cultures around the world mark the occasion in some way, as Minnesota author Selby Beeler learned.

She was at her father's house one day with her daughter Amanda. "Suddenly I heard these stomping feet coming down, and this voice going, 'Mom, Mom, my tooth fell out! Do you think the tooth fairy will come?'" Beeler recalled. Her father was a physician and one of his patients was there — a woman from Brazil. "What's a tooth fairy?" she asked. After a quick explanation, the woman explained that, as a child, she tossed the tooth up in the garden so that the little birds would take it and bring her a new one.

"I'd never thought about what other people did with their teeth," Beeler said. That encounter ultimately led her to write the children's book "Throw Your Tooth on the Roof: Tooth Traditions From Around the World."

Although Beeler describes many different cultural responses to the loss of a baby tooth, from the custom described in the title to that of dropping the tooth down a mouse hole, she does not think that reading these stories will stop children here from believing in the tooth fairy. Knowing that children in Mexico are visited by El Ratón does not seem to upset their paradigm.

A child's way of thinking

Ira Glass might call this "kid logic." The host of the radio show "This American Life" described another potentially faith-shaking tooth-fairy encounter in an episode on that peculiar brand of logic. In that show, a young girl tells her best friend that she woke up and saw her father putting money under her pillow after she had lost a tooth. Both girls then decide that the father must be the tooth fairy — that is, for all children.

"Why did both girls come to what seems like the least likely conclusion from the evidence in front of them?" Glass asked in the episode.

Koenig said that children are not so credulous as we might think. They believe in fantasy characters such as Santa Claus, the Easter Bunny and the tooth fairy in part because these characters receive widespread cultural support. The purely secular, homegrown-American tooth fairy enjoys some of the most widespread support of all these characters, and the ritual is practiced in a remarkably homogenous way across the country, Koenig said.

From pillow to pillow, the most marked fluctuation may be in the amount of money the tooth fairy leaves a child. While $1 is common, "we see everything from $5 to $20," said Dr. Joni Richmond, a dentist with the Metropolitan Pediatric Dental Association. The average amount has risen over the course of the tooth fairy's existence. Even the tooth fairy must keep up with the rate of inflation, it seems.

One trend that Richmond has been seeing recently is children wanting to keep their teeth. Madeline, as excited as she was for the tooth fairy to visit, felt that way. Now, after the loss of her third tooth, a tradition is well established in the Hanstad household. Along with a dollar bill, Madeline receives a handwritten note telling her that the tooth fairy has inspected her tooth and that she may keep it.

Her parents plan to do the same thing for their second daughter, now 4 months old, although they wonder if it will be as easy to keep the secret.

"It might be a little bit harder when we get to that point — having an older child, that could possibly ruin it," Christen said with a laugh.

Sarah Rose Miller is a Minneapolis freelance writer.