Tooth Fairy guilty of favouritism!

To determine the proportion of children visited by the Tooth Fairy, the child-related factors that influence the likelihood of her visit, and the parent-related variables that affect the amount of money the Tooth Fairy leaves.

Cross-sectional questionnaire study.

Zürich, Switzerland.

3617 parents of children (mean age of children, 6.8 years; 51.9% girls) who had lost at least one deciduous tooth received a self-developed questionnaire; 1274 questionnaires were returned (35.2%).

Primary outcome variables were the Tooth Fairy's visit after tooth loss and the amount of money given in case of a visit. Child- and parent-related variables were assessed as predictors of the main outcomes.

Most parents (71.0%) reported that the Tooth Fairy visited their child. She usually exchanged the lost tooth for money (55.8% of visits) or placed money next to the tooth (40.7%); rarely did she take the tooth without pecuniary substitution. The Tooth Fairy left an average of 7.20 Swiss francs (approximately AU$9.45). The Tooth Fairy favoured visiting for the teeth of older children (odds ratio [OR], per year, 1.87; 95% CI, 1.09-3.21), of boys (OR, 2.65; 95% CI, 1.09-6.42), and of children who believed in her (OR, 4.12; 95% CI, 1.77-9.64). The amount of money was influenced by maternal, but not paternal socio-demographic factors, including level of education (OR, per level, 0.78; 95% CI, 0.66-0.92) and country of origin (OR, Western countries v non-Western countries, 2.35; 95% CI, 1.20-4.62).

The Tooth Fairy does not visit all children after tooth loss, displaying clear preferences in her choice of business partners. The odds of a visit are dramatically increased if she is believed in, and the value of a deciduous tooth is influenced by socio-demographic factors.