The whole 'tooth': Daniel Radcliffe spills on why Harry Potter’s young cast had to wear fake teeth on set

While the first two Harry Potter films from director Chris Columbus were full of fantastical elements, a very different kind of magic was needed behind-the-scenes during filming. Movie magic, that is. 

While promoting Miracle Workers at Sundance, Daniel Radcliffe (Harry Potter) and Karan Soni (Deadpool's Dopinder) revealed that because the cast was so young for the earlier films, their baby teeth kept falling out. As such, the production crew had to create fake replacements whenever this happened.

"They would have a cast made of all their teeth, so that if one fell out, they could have a prop tooth put in, so they could keep filming" said Soni, who was asked what he had learned about the Potter movies while working with Radcliffe.

"You've got a set of 20 10-year-olds," added Radcliffe . "So they just cast everyone's mouths."

Re-growing bones (yes, teeth are bones) via magic pops up a number of times in J.K. Rowling's Potter series. In Chamber of Secrets, the inept Gilderoy Lockhart removes all of the bones in Harry's arm after a Quidditch match. As a result, he needs to spend a painful night in the Hogwarts hospital wing, where he must drink the foul-tasting potion known as Skele-Gro. In Deathly Hallows, Ted Tonks regrows one of Harry's teeth after Harry and Hagrid, pursued by Voldemort through the skies, crash in the Tonks family pond.

The next Wizarding World film to grace movie screens will be the third installment to the Fantastic Beasts franchise, whose production was just pushed off until the fall.

Miracle Workers, a workplace comedy set in the offices of Heaven, premieres on TBS February 12. In addition to Radcliffe and Soni, Steve Buscemi plays God Himself.