Holly Thompson, 17, of Kingsthorpe, Northampton, was in the middle of a particularly enthralling class on politics when she reacted to the subject matter like many other students would -- she yawned.
But what happened next wasn't so typical. Her trap wouldn't shut, making her look like an anime character in a state of shock.
"I was so shocked, my expression probably said it all," she said. "I nudged my friend to show her what had happened but I was so embarrassed. When we realized we couldn't close it, she had to tell the teacher."
Adding insult to injury was the reaction from teachers and classmates. "All my classmates and teachers thought it was really funny, everyone burst out laughing. It was awful," she said.
Although the school nurse tried everything to jam the jaw shut, including putting a hot water bottle under her chin and using ice packs, MSNBC reported that Thompson eventually was sent -- dangling choppers and all -- to the hospital for additional treatment.
The doctor on duty, Ejiro Obakponovwe, didn't think Thompson's injury was a laughing matter.
"It can be quite serious, because she can't eat, can't really drink, and you get really dehydrated," Obakponovwe told the BBC show "Bizarre E.R." "But again, it's quite painful as well."
The good doctor tried an unusual and, some might say, depressing technique: She placed 26 tongue depressors in Thompson's mouth.
"The tongue depressors allowed the jaw to get tired, relax, so the jaw can click back into place," Obakponovwe said.
The treatment worked, but it still pains Thompson to talk about it.
"I thought they were just going to give me some medicine, not put splints in there."
Thompson's jaw was stuck in the open mouth, insert foot position for five hours. She ached for a few more hours afterward. Although tired, her doctor warned her to suppress expression.
"She has to avoid yawning," Obakponovwe said. "The jaw's a bit unstable."
What's happened to Thompson since her injury is even more jaw-dropping. She's become quite popular on YouTube. Ryan Seacrest even tweeted about her injury.
"That's great," she said. "But I think I'd rather be famous for something else."
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