image by: Samuel Regan-Asante on Unsplash

HWN Suggests

A hidden epidemic of shrinking jaws is behind many orthodontic and health issues, Stanford researchers say

For many of us, orthodontic work – getting fitted with braces, wearing retainers – was just a late-childhood rite of passage. The same went for the pulling of wisdom teeth in early adulthood. Other common conditions, including jaw pain and obstructed sleep apnea – when slack throat muscles interrupt breathing during rest – also just seem like par for the course. The broader scientific community has largely deemed the underlying abnormality behind these problems as hereditary and untreatable, and opted to deal with symptoms through medical devices and after-the-fact interventions. But in a new study, Stanford researchers and colleagues argue that all these issues and more are actually relatively…

read full article

Featured

 Human jaws are surprisingly strong and efficient

Humans, it is said, have relatively weak jaws that can’t inflict or withstand high bite forces. Some have suggested that we are adapted to eat foods that aren’t very tough, or that our use of tools and cooking has lessened the evolutionary pressure on maintaining sturdy jaws. Some have even suggested that our weedy jaw muscles made way for our large brains and thus facilitated their evolution. But according to Wroe, all of these explanations have a fatal flaw – our jaws aren’t weak at all. They’re actually remarkably efficient for a primate.

Articles of Interest

Facts You Might Not Know About the Jaw

The human jaw consists of a moveable lower jaw and a fixed upper jaw, both of which hold teeth in place. The jaws move in opposition to each other for the main purposes of biting and chewing foods. Your jaw can have a major impact on your oral health, affecting the alignment of your teeth as well as your ability to eat or speak.

Jaw Anatomy

Having a basic knowledge of the anatomy of the jaw helps patients better communicate their symptoms, participate in treatment decisions, and actively manage their condition.

Jawbones are 'shaped by diet', a study finds

Many scientists have suggested that the range of skull shapes that exist within our species is the result of exposure to different climates, while others have argued that chance played more of a role in creating the diversity we see in people's profiles. The new data, collected from over 300 skulls, across 11 populations, shows that jaws shortened and widened as humans moved from hunting and gathering to a more sedentary way of life.

The Human Jaw: A Closer Look at Our Unique Anatomy

The mandible is the only movable part of our skull; it hinges open and closed thanks to muscles like the masseter and temporalis. This movement enables us not just to eat but also to communicate effectively with others.

The mandible and its features

The mandible is the largest and strongest bone of the face. It creates our lower jaw and holds the lower teeth. The bone articulates with the temporal bone to form the temporomandibular joint, allowing us to talk, eat, and yawn ?.

The Power of the Human Jaw

A TEN-POUND bite requires a forty-pound contraction of the human jaw muscles. That is because the jaws are built on the principle of a pair of tongs, The power is applied near the joint, while the work is performed at the opposite extremity of the jaw levers. Had a mechanical engineer designed the human frame, he would no doubt have built the jaws after the fashion of a nut cracker, with the muscles placed at the ends of the jaw levers, and the teeth between these ends and the joint or fulcrum, so that a powerful bite could be obtained with a very small expenditure of muscular effort. However, in the physiology of man and all other animal life, for that matter, mechanical advantage weighs for little in the presence of other broader considerations.

Weak Jaw, Big Brain

Our brain is three times the size of our ancestors' and a muscle protein may be behind its rapid expansion. The protein is a building block of jaw muscles, and the discovery of a mutant form in all humans studied to date--but in no other primates--suggests that it played a role in human evolution, resulting in smaller muscles around the skull that made it easier for the brain to get bigger.

Resources

TeachMe Anatomy

The mandible, located inferiorly in the facial skeleton, is the largest and strongest bone of the face. It forms the lower jaw and acts as a receptacle for the lower teeth. It also articulates on either side with the temporal bone, forming the temporomandibular joint.