We recently talked about the amazing architecture of Tyrannosaurus rex’s teeth. Now a new study reveals that T-Rex’s jaws were awesomely designed for wielding those deadly knife teeth, capable of opening nearly 90 degrees with straining. This study emphasized the importance of a harmonious relationship between teeth and jaws in the proper functioning of your bite.
Determining Maximum Jaw Gape
For this study, researchers looked at the skulls of three dinosaur species and two living animals, American alligators and common buzzards. They used a computer program to set up muscles on 3-D models of the skulls and determine how far these muscles could stretch, based on known parameters for muscle performance.
They found that the muscles would allow for very wide gapes in T-Rex and Allosaurus fragilis, a relative who hunted across much of North America millions of years before the appearance of T-Rex. However, the related Erlikosaurus, a relative that is suspected to have had a vegetarian diet, wasn’t able to open its jaws nearly as wide. T-Rex jaws could open up to a maximum of about 80 degrees.Allosaurus could open its jaws even wider, perhaps 92 degrees. Erlikosaurus jaws could only open up to a maximum of 49 degrees.
When T-Rex fully opened her jaws, the teeth were more than five feet apart. That’s about 25 times larger than the maximum jaw opening of a healthy adult man.
Jaw Muscles and Function
The study also looked at the way that the muscle configurations supported the lifestyle of the animals. Researchers noted that T-Rex’s teeth were designed for puncturing flex and crushing bones, and that their jaw would support this use, allowing for high levels of crushing force at all angles.
Allosaurus, on the other hand, had smaller teeth, designed for grasping, cutting, and tearing, and its jaw muscles and bones were not as strong. Erlikosaurus had comparatively weak jaws, which they say is more evidence of an herbivorous diet. They also note that in order to function with such weak jaw muscles, it often recruited neck muscles to help strip leaves from trees and bushes.
How Is Your Jaw Function?
As with dinosaurs, for us a healthy jaw is essential to a healthy life. Because of our omnivorous diet and the other functions we use our mouth for humans have a uniquely adapted temporomandibular joint that allows for great flexibility. Unfortunately, with this flexibility can come vulnerability, and temporomandibular joint disorder (TMJ) is common. If you find the opening of your jaw is limited, or if using your jaw is painful, we may be able to help.