This whole case is so absolutely bizarre, we simultaneously can and cannot believe an entire episode was dedicated to Gypsy's teeth. In the show — which disclaims at the end of each episode that their narratives are fictional, though largely based on real events — Gypsy begins to sneak out of bed in the middle of the night to mainline loads of sugar, via whipped cream, Coca-Cola and candies, which are strictly forbidden by her mother.

Gypsy develops something of a sugar addiction, though her mother continuously tells her and those around her that she's mortally allergic to sweets. Over the course of the episode, we watch as her teeth rot into what Dee Dee describes as "swiss cheese," which get so bad that she bleeds while brushing and eventually has to have all but four of them extracted in an incredibly hard-to-watch dentist scene.

And although it's true that the real Gypsy's teeth were "crumbling and painful," to the point where they "rotted out and had to be extracted," per Michelle Dean's Buzzfeed report, her Coca-Cola-fueled late nights might have just been something the show's creators dreamt up.

Because in real life, it was Dee Dee's repeated abuse of her daughter that made Gypsy have to get all her teeth extracted. According to the HBO doc, the culprits in her tooth decay were the extremely strong medications Dee Dee made her daughter take for conditions like epilepsy, MS, and leukemia that Gypsy didn't really have. 

In an interview with ABC News, Gypsy revealed her mother would use a numbing agent on her gums to make doctors remove her salivary glands, and that this may have contributed to the rot and eventual decay and extraction of her teeth. But according to a later interview with Dr. Phil, Gypsy says Tegretol, which she was prescribed for her non-existent epilepsy, is what caused her "teeth to crumble."