Researchers at the University of Basel discovered a new muscle layer in the human jaw that aids in its stability. The discovery had previously gone unnoticed by researchers. According to the discovery, it can pull the lower jaw backward, toward the ear. If it is attached to the muscular or “coronoid” process of the lower jaw.
The masseter muscle is the largest and most visible of the jaw muscles. You can feel the muscle tighten by placing your fingers on the back of your cheeks and pressing your teeth together. The masseter is typically described in anatomy textbooks as having one superficial and one deep part. So the researchers decided to see if the prominent jaw muscle had a hidden, super-deep layer, as suggested by historical texts. According to the report, they dissected 12 human cadaver heads that had been preserved in formaldehyde. They also took CT scans of 16 “fresh” cadavers and reviewed an MRI scan from a living subject.
This deep section of the masseter muscle is clearly distinguishable from the two other layers
They learned an “anatomically distinct” third layer of the masseter muscle during these examinations. The zygomatic process, a bony prognosis that forms part of the “cheekbones” and one can feel it just in front of the ear to the coronoid process. A triangular projection on the lower jawbone. It is part of this deep, deep layer. Szilvia Mezey of the University of Basel’s Department of Biomedicine is the study’s lead author. “This deep section of the masseter muscle is clearly distinguishable from the two other layers. Especially in terms of its course and function,” she said.
The team however recommended calling the new muscle layer “Musculus masseter pars choroidea.” It implies “coronoid part of the masseter,” in their paper. The finding could be certainly crucial in a clinical setting. Because learning about the muscle layer could assist professionals to conduct better surgeries. Especially in that region of the human jaw. And treat ailments involving the joint that connects the jawbone to the skull, they noted.