Crocodiles Don't Need Thick Teeth Enamel; They Just Grow New Ones
Crocodiles are known for having a fierce bite but they don't have to worry about cleaning those chompers, even after human meals. New research found they have thin teeth enamel, implying they shed old teeth and grow new ones.
Using a three-dimensional x-ray scanner, researchers at the University of Missouri measured the thickness of tooth enamel in crocodiles and found it to be thin, completely opposite of what is found in humans and other species that have a hard bite. It has long been assumed that hard teeth are required for a hard bite.
Crocodiles don't need thick teeth for a tough bite
The thin enamel was present regardless of the position of the tooth, age of the crocodile or its diet. This newfound knowledge, which was published in the Journal of Zoology, could be used to develop new techniques for caring for human teeth, the researchers said.
"Once we unlock genetically how crocodiles and other non-mammals do this, maybe new teeth can be bioengineered for people," said Brianne Schmiegelow, a former undergraduate student at MU and current dental student at the University of Missouri-Kansas City in a press release announcing the results of the research. "Instead of using fillers such as crowns, people could instead 'grow' new teeth when they need to replace their worn-out chompers."
Dinosaurs have thin teeth enamel too
Armed with that knowledge that crocodiles have thin teeth enamel, the researchers studied dinosaur teeth data and discovered both share that attribute. Take a Tyrannosaurus rex for one example. This meat-eating pre-historic dinosaur has the same enamel thickness that a crocodile has. That led to further research to see if tough teeth are required for a tough bite. The University of Missouri researchers concluded that the reason crocodiles and other animals don't need thick enamel is that they grow new teeth.
The researchers plan to take their work to the next level by studying tooth replacement and the timing of tooth growth in crocodiles and dinosaurs with an eye toward identifying genetic causes.
"Enamel takes a long time to build, so it's not something animals will do 'off-the-cuff,' so to speak," said Casey Holliday, an associate professor of anatomy in the MU School of Medicine in the same release. "It presents us with an interesting puzzle. If ancient crocodiles were chewing plants, did their new teeth already have the correct architecture—dimples and facets—to allow for this chewing? The findings here have paved the way for exploring this mystery with future research."
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