Scientists Have Just Identified A New Part Of The Human Body

Specifically, this new muscle is a deeper third section of the masseter muscle, which elevates the lower jaw and is essential for chewing.

Specifically, this new muscle is a deeper third section of the masseter muscle, which elevates the lower jaw and is essential for chewing. To date, anatomy textbooks often describe the masseter as superficial and deep, without this additional third layer.

“Some historical texts mention the possible existence of a third layer as well, but are extremely inconsistent in its position,” the study authors wrote. For this reason, taking what historical texts suggest, the team decided to test whether the prominent jaw muscle could have a hidden, super-deep layer.

The third layer “anatomically distinct”

By analyzing more than two dozen human heads, including that of a living subject and that of 12 heads preserved in formaldehyde, the researchers led by Szilvia Mezey, from the Department of Biomedicine at the University of Basel, and Professor Jens Christoph Türp, from the University Center for Dental Medicine in Basel (UZB), identified the third “anatomically distinct” layer of the masseter muscle.

This very deep layer runs from the zygomatic process –bony projection that forms part of the “cheekbones” and that can be palpated just in front of the ear– to the coronoid process –triangular projection in the lower jaw.

Stabilize the lower jaw

Depending on the arrangement of the muscle fibers, the muscle layer is likely to help stabilize the lower jaw by “lifting and retracting” the coronoid process, the team wrote in their report. And in fact, the new muscle layer is the only part of the masseter that can pull the jaw back, Mezey said.

New Part Of The Human Body

“Although it is generally assumed that the anatomical research of the last 100 years has left no stone unturned, our finding is a bit as if zoologists discovered a new species of vertebrate,” Türp said in the statement.

In their study, the scientists propose that this layer be called Musculus masseter pars choroidea – that is, the coronoid section of the masseter – because the muscular layer just described is attached to the muscular process (or “coronoid”) of the lower jaw. according to a statement from the University of Basel.

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