Why This Newborn's Smile Is So Rare

— -- Alyssa Bailey was born three days after Christmas with a little something extra -- two bottom front teeth.

The doctors and nurses who delivered her were quite taken with this dental surprise, said the baby's mom, Jaklina Bailey.

"Right when she first arrived, everybody was just shocked," the mother told ABC7, the ABC affiliate in Branson, Missouri, where the baby was born. "Just like, 'She has two front teeth? No kidding? Really?' It was just a big talk about it, you know, in the delivery room."

While not common, it's not unheard of for babies to be born with fully formed teeth, said Dr. Laura Corio, a clinical professor of obstetrics and gynecology at Mount Sinai Hospital in New York City.

"Teeth can be present in oral cavities at birth and may be related to certain other health problems but not always," Corio explained.

About one in every 2,000 to 3,000 babies are born with teeth, according to the National Institutes of Health. Like Bailey, they usually appear on the lower gums but on occasion you'll see a baby born with a mouthful of chompers, Corio said.

Typically, the doctor will remove or shave down the natal teeth as soon as possible to avoid problems with nursing and prevent the baby from cutting its tongue, said Corio.

In baby Alyssa's case, her mom said they're going to keep an eye out to ensure the tiny teeth don't come loose and present a choking hazard. But since they're an extra set, once they fall out, doctors are confident her usual baby teeth will grow in normally.

To keep up with breaking health and medical news, follow ABC News Health on Twitter.