Since the actors were so young when they started filming, they had to deal with losing their baby teeth while on set. To fix this issue, the crew made moulds of the cast's teeth to make fake teeth to replace them!
Daniel Radcliffe (Harry Potter himself) confirmed the weird piece of information to The Hollywood Reporter when promoting his movie Miracle Workers.
Daniel stars in the new movie alongside Deadpool's Karan Soni, and he shared the story during filming.
Soni explained, “When they were doing the earlier movies, because their teeth were falling out, they would have a cast made of all their teeth. So that if one fell out, they could have a prop tooth put in. Just so they could keep filming.”
Daniel confirmed it, saying, “Cause you’ve got a set full of twenty 10-year-olds… they would cast everyone’s mouths.”
Lucky they had magic!