Upon its release on Sept. 17, 2021, “Squid Game” quickly became an international phenomenon. But before it became Netflix’s most popular series of all-time, Hwang Dong-hyuk, its creator, had paid a physical price to make it happen: Six (six!) of his teeth had fallen out during the show’s production. Hwang, who'd famously had dreamed up “Squid Game” years before as a movie, with the story born out of his own financial struggles during the Great Recession, had written and directed every episode of the show — and that stressful immersion had taken a toll.