Doctors have raised concerns about the tooth fairy following "mounting reports of less child-friendly activity".
A group of paediatricians and a consultant radiologist from London voiced their concerns while writing about a number of cases of tooth fairy "malpractice".
One eight-year-boy became distressed after the mythical creature "put a tooth in his left ear" after he left it under his pillow.
The tooth was eventually found three years later when doctors identified a "foreign body" lodged inside the child's ear canal.
"The patient decided to keep the tooth for posterity rather than taking the risk of attempting a further pecuniary reward," the authors wrote.
In the paper, published in the BMJ Christmas edition, the doctors also detail two other cases of tooth fairy misdemeanours.
One man developed an abscess after placing his child's tooth in his nipple piercing so it could be "near to his heart".
And there was another report of a tooth which was supposed to be taken away by the tooth fairy but instead caused an airway obstruction in a patient, leading to a "trauma situation".
The authors said: "We are concerned that the actions of the mythical character at the root of this report must be brought to the attention of the medical community, as it seems to represent the first signs of a worrying new trend in malpractice.
"Previous anecdotal evidence suggests the tooth fairy is benevolent, but this opinion may need revising in light of mounting reports of less child-friendly activity."