Gators may grow 4,000 teeth over their lifetimes.
By Francie DiepPosted 05.15.2013 at 11:02 amhttp://www.popsci.com/science/article/2013-05/dentists-looking-regrow-teeth-study-alligators
Toothy National Park Service Photo by Rodney Cammauf
Once your adult teeth come in, that's all you've got to work with. Knock one out, or lose a few to decay, and you'll have to get dentures. It's a pain, but at least one team of dental researchers is now studying how to regrow human teeth—by looking at alligator teeth first.
American alligators have 80 teeth, each of which they replace about once a year. Over their long lives, an alligator may regenerate something on the order of 4,000 teeth. So a team of researchers from the U.S., China and Taiwan performed a detailed study of alligator teeth to learn their secret.
Of course, a study of alligator teeth is a long way from being able to grow new human teeth, but that's the eventual goal of research like this. Understanding how alligators regrow their teeth may also help scientists better understand rare genetic diseases in which people grow extra teeth or tumors from the tooth bed.
To perform their study, the researchers took snapshots of alligator teeth as the teeth cycled through stages of growth. They injected living juvenile alligators with a chemical that helped them visualize cells in the alligators' tissues that were growing and multiplying. They already knew that alligators have small replacement teeth waiting just underneath all their mature teeth, but these new experiments allowed the researchers to watch exactly what happens to the mature tooth, the replacement tooth and the bed the replacement tooth grows from, called the dental lamina, at different stages.
They even pulled teeth from alligators sooner than they would naturally shed, to see how the replacement tooth and dental lamina reacted.
The researchers concluded that the dental lamina likely has stem cells that help it regrow teeth. They also performed experiments to find what genes likely govern 'gator tooth growth.
They published their work in the Proceedings of the National Academy of Sciences.
