Tyrannosaurus rex has long been the star of children’s imaginations, remaining one of the most popular and beloved dinosaurs since its discovery more than 100 years ago. One of the stars of the Jurassic Park franchise, the dinosaur has gained even more popularity recently. With more than 20 skeletons identified with this species, it’s also one of the best-studied dinosaurs, but we continue to learn some amazing things about Tyrannosaurus every day, including a recent discovery about their teeth.
In the past, it was thought that tiny cracks in fossil Tyrannosaurus teeth were either artifacts of the fossil record or were the sign of wear, it has recently been proposed that the cracks had an essential purpose to help Tyrannosaurus maintain the serrations that let the dinosaur tear huge chunks of flesh off its prey.
A Flaw That Adds Strength
The initial explanation that Tyrannosaurus teeth became cracked by wear didn’t hold up when Kristin Brink and other researchers at the University of Toronto looked at teeth that hadn’t yet erupted from the carnivorous dinosaur’s jaw. These unerupted and therefore unworn teeth also featured the cracks, which meant they had to have some functional or developmental purpose.
Analyzing the structure of the teeth in more detail, it turns out that the cracks helped avoid wear of the serrations. this would help the teeth stay functional and in place long enough for the Tyrannosaurus to develop replacement teeth. Always having a full mouth of highly functional serrated teeth would have given Tyrannosaurus and its relatives a competitive advantage, allowing them to spread and remain at the top of the food chain for over 160 million years.
How Cracking Helps Your Teeth
Our teeth aren’t 9-inch steak knives designed to slice through the flesh of a huge dinosaur carcass, but our teeth also take advantage of cracks to help stay strong. The dental enamel in our teeth is a very hard material, but with hardness can come brittleness, which would make our teeth shatter whenever we bit down on something very hard, like a popcorn kernel.
To avoid this, our enamel is arranged in tiny bundles of rods. When our teeth are subjected to significant bite forces, the soft dentin inside the tooth flexes, and the enamel, instead of breaking, separates because it can’t flex.
At first, these separated fibers are invisible, but later you may notice them as craze lines in your front teeth. Over time, these cracks can get bigger and turn into serious problems. Repeated flexing associated with TMJ or with bruxism can also make your teeth vulnerable to erosion, as the separated fibers can’t hold each other in as well.
In other words, although the cracking does help protect our teeth, eventually it will contribute to tooth wear and destruction.
If you have suffered cracked or broken teeth, you can’t unfortunately, grow a replacement like a T-rex. But we can do the next best thing: covering damaged teeth with same-day dental crowns or replacing those that are too damaged with dental implants.