When you grit your teeth, you feel a group of muscles contracting right in front of your ear. The new kid is at the top of this muscle group. If he could have gone unnoticed during all these years, it is because he is hidden in the depths of a muscle that is well known to him: the masseter muscle. Anatomy books have so far described this masseter muscle as being made up of two parts, two layers of muscle, but in fact there are three.
It is this new muscle layer that has just been clearly identified and described by researchers at the University of Basel in Switzerland. And this muscle layer has a very specific function: it stabilizes the lower jaw and makes it move backwards, towards the ear, when you tuck your chin in. It is a muscle that plays an essential role in chewing.
This discovery should be used by dentists and surgeons to rehabilitate and treat jaw dysfunctions. Moreover, even if this new muscle, called the coronoid masseter, is only a very small layer of muscle fibers out of a total of more than 600 muscles in the human body, in terms of scientific novelty, “it is as if zoologists discovered a new species of vertebrate” indicated the authors of this work.
This coronoid masseter muscle is not very big, but it is far from the smallest in the human body. The smallest is in the ear, in the ear canal. And the largest and most powerful muscle in the human body is the gluteus maximus, the muscle that helps you stand up and extend the thigh.
Do we burn more calories at rest when we are muscular? The difference is not huge. If the muscle mass increases by 20% it only increases the basal metabolism by 4 to 5%. So with 20% more muscle, a 90 kg man will be able to swallow an additional 100 calories, which corresponds to three squares of chocolate or a sixth of a hamburger. So even with an athletic body, there is justice, you still have to move to keep the line.