Warning: Some may find the video disturbing to watch.
Sara Guidry, from Louisiana, US, said she was looking in her son Kale’s mouth when she saw something white in his gums, so used tweezers to pull it out.
She realised shortly after that it was a fingernail and so searched his mouth to see if there were any others.
“I then searched his mouth and find another area,” she wrote on YouTube. “I pulled around 27 out of the second spot. YES 27!
“The dentist has never seen anything like this.”
The video shows Guidry pulling several fingernails out of her son’s gums - including the roof of his mouth.
She said she shared the video to warn other parents about the consequences of letting their children bite their nails.
“We figured out that Kale bites his nails and plays with them in his mouth,” she added.
“He pushes them up towards his pallet. The nail penetrates the skin and goes into a pocket between the baby teeth and permanent teeth.
“Don’t let your children bite their nails!”
The video had nearly 200,000 within four days of posting.