T. rex's nine-inch, serrated teeth: A dentist's dream or nightmare?

New research found that unique serrations make Tyrannosaurus teeth highly resistant to damage, thus helping the dinosaur and its relatives secure their place at the top of the prehistoric food chain.

A boy looks inside the skull of a Tyrannosaurus Rex replica at the Egidio Feruglio Museum in Trelew, Argentina, in May 2014. Scientists today unveiled a comprehensive analysis of the teeth of the group of carnivorous dinosaurs called theropods, which include the Tyrannosaurus Rex, detailing a unique serrated structure that let them chomp efficiently through the flesh and bones of large prey.

Maxi Jonas/Reuters/File

July 28, 2015

The Tyrannosaurus rex had its teeth to thank for its status as “king” of the dinosaur world, according to new research released today.

A University of Toronto Mississauga study published in Scientific Reports found that theropods – the group of carnivorous dinosaurs to which the T. rex belonged – had “saw-like,” serrated teeth that allowed them to penetrate the flesh and bone of their prey, which is likely what made them such formidable hunters.

UTM paleontologist Kirstin Brink and her colleagues on the research team say that scientists who studied teeth from the Albertosaurus theropod in the early 1990s were wrong to believe the cracks they saw were due to damage.

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“I sectioned teeth from eight other arthropods besides Albertosaurus, and found that the structure is in all theropods, and it’s not actually a crack,” Ms. Brink told LiveScience.

Aside from being structured like steak knives, T. rex teeth were big – about nine inches long. The serrations went deep to strengthen the teeth and prevent damage, UTM paleontologist Robert Reisz said in the press release. But even if a dinosaur lost a tooth, a new one would grow back; unlike humans, dinosaurs grew new teeth throughout their lives.

The problem was that it took a while for a tooth to replace itself. Brink said "It could take up to two years for a tooth to grow back in the big theropods like T. rex.”

“Therefore, having specially reinforced teeth means less tooth breakage and less gaps in the jaw, leading to more efficient eating.”

Today, the only animal with a similar tooth structure to that of theropods is the Komodo dragon which, like theropods, preys on large animals.

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"What is so fascinating to me is that all animal teeth are made from the same building blocks, but the way the blocks fit together to form the structure of the tooth greatly affects how that animal processes food," Brink said in a press release. "The hidden complexity of the tooth structure in theropods suggests that they were more efficient at handling prey than previously thought, likely contributing to their success."

This report contains material from Reuters.