Humans May Evolve To Grow An Endless Supply Of Teeth

 

In the future, you--like the pufferfish--could have so many teeth that you'll wear necklaces made out of your spares. It'll be weird.

Friendly Pufferfish Wikimedia Commons

The pufferfish is a very curious animal for lots of reasons; it swallows air or water to make itself larger and more threatening, it combines its combining pectoral, dorsal, anal, and caudal fins into one set of fins (like a seahorse), and it is often super poisonous. But Dr. Gareth Fraser of Sheffield University is focused on the puffer for a different reason: its teeth.

The puffer, like lots of bony fish (meaning, not cartilaginous), constantly regrows its teeth. The puffer doesn't have delineated teeth like most other fish, though; instead, after its first set of teeth have fallen out (like human baby teeth), it grows a solid structure that looks like a beak. This beak is made of horizontally growing layers of dentite, the usual tooth material for fish, but appears as a single band.

Fraser managed to map the specific cells responsible for the constant regrowing of teeth in the puffer. That's of great interest to us, because humans, unlike lots of other animals, only grow two sets of teeth. Your baby teeth fall out, then you grow your adult teeth, and then...that's it. That's all you get. And that's less than ideal, as most any professional hockey player can tell you (through gaps in their teeth).

Interestingly, Dr. Fraser thinks humans may evolve, in millions of years, the ability to regrow teeth past that second set. "With our extended lives and modern diets, the limited supply of human teeth is really no longer fit for purpose," he said. By figuring out exactly how fish regrow teeth, he may be able to accelerate that process of evolution.

So play hockey without fear! A fix for your broken grill may be in the works.

By: Dan Nosowitz
July 12, 2013

Should you suck on a pacifier before giving it to your baby?

A new study in Pediatrics, journal of the American Academy of Pediatrics, reports that parents sucking their infant’s pacifier may reduce the risk of allergy development.

The ADA wants parents to be aware that licking a pacifier can transfer the cavity-causing bacteria from parents to children—increasing the possibility of tooth decay as they grow.

"A child's teeth are susceptible to decay as soon as they begin to erupt," said Dr. Jonathan Shenkin, a pediatric dentist in Maine and a pediatric dental spokesperson for the ADA. "Cavity-causing bacteria, especially Streptococcus mutans, can be transferred from adult saliva to children, increasing their risk of getting cavities."

Sharing eating utensils with a baby, or the parent sucking on a pacifier to clean it, can also increase the likelihood of transmitting decay-causing bacteria.

The ADA recommends that parents protect the dental health of young children by promoting a healthy diet, monitoring their intake of food and drink, brushing their teeth or wiping gums after mealtimes, and by having infants finish their bedtime or naptime bottle before going to bed. The ADA recommends that children receive their first dental visit within six months of eruption of the first tooth and no later than 12 months of age.

May 2013 - ADA.org