The jaw bone is a very important part of the skeletal system and critical for our survival. The jaw aids in swallowing liquids and food, is an integral part of talking, and chewing would be impossible without it. The jaw, the lower part of which is known as the mandible, can exert from 50 to 200 pounds of pressure per square inch when we chew. The “jaws of life”, used to free people from cars who’ve been in a motor vehicle accident, is modeled after the human jaw.
When do men’s jaws stop growing? While there are contradictory answers (some say jaw growth stops at sixteen years old while others claim jaw growth continues to age 25 before stopping), scientists conclude that jaw growth continues throughout life, even into later ages.
The changes that occur in adulthood are smaller when compared to growth periods of the body in youth, but the jaw, a component of the craniofacial skeleton, is seen as never stopping its growth and change.
This information is hugely important to dentists, dental surgeons and orthodontists. Knowing more about the jaw and mandible can help you avoid issues with the most complex part of the jaw, the temporomandibular joints, or TMJ.
When problems arise in this highly complex part of the jaw, a variety of symptoms arise that are difficult to diagnose, and even harder to treat.
When teeth are lost either by way of decay or an accident by way of sports activities, the jawbone erodes away also, because it isn’t being used for the purpose it was made for.
The solitary function and reason for existence of the jawbone, is to support the teeth. The TMJ joint is part of an intricate set of muscles and ligaments; with skin, they all serve to hold the jaw in place.
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What is the Temporomandibular Joint?
The temporomandibular joint connects the jaw to the skull. There is one TMJ joint on each side of the head. Disorders to the TMJ can cause pain in the joint of the jaw, and worse, cause pain in the muscles that control the movement of the jaw.
The cause of the pain in the TMJ joint is still not known, which is why TMJ disorders are as complicated as the muscles and ligaments which comprise the TMJ joint. Sometimes the pain is due to genetic factors, or arthritis, and sometimes due to an injury to the jaw.
Teeth clenching and grinding can cause TMJ joint pain as well; some people can clench and grind teeth all their lives and never develop any pain.
Surgery is a last resort since in the majority of cases, the pain is temporary. For some unfortunates, the only way to treat the pain is with surgery.
TMJ disorders are also responsible for changes in facial appearance when the muscles become disorganized. When the bite becomes off balance or when teeth shift, the face can look different than in is natural, healthy state.
How Does The Mandible Work?
The mandible is the largest and strongest bone on the face. The mandible supports and functions for the teeth, for chewing and swallowing. It is the lower part of the jaw, on which the bottom set of teeth rest.
The maxilla of the jaw supports and serves the upper set of the teeth. But it is the lower jaw that, with muscles of the mouth attached, opens and closes the mouth and moves up and down and right to left during mastication (chewing), talking and swallowing.
Four muscles attach to the lower jaw to facilitate movement: the masseter, the temporalis, and the medial and lateral pterygoids. These muscles enable the jaw to move in four directions: up, down, left, right.
Which Jaw Shape is Most Attractive in Men?
The results are in and the consensus is that the overall shape of a man’s face is most important to his sex appeal. There is a shorter distance between the lips and the eyebrows in men than women, making the larger jawbone appear larger.
Men have evolved short faces between the lips and eyebrows, making not only the jaw more prominent, but also making the eyebrows more pronounced and the cheeks appearing to be larger as well as the jaw.
Are There Procedures That Can Alter the Shape of the Jaw
Over time as we age, the jaw changes shape dramatically. A jaw of a man 35 years old is more prominent than the same man at 65 years old. This is one of the reasons that older people look so different than when they were younger.
These changes to the underlying facial bones being takin up by plastic surgeons and doctors who perform reconstructive surgery.
It is not only the jaw, which seems to compress and appear flatter on older people than younger ones. The eye sockets become larger, eyelids droop and the angle of the bones beneath the eyebrows grows smaller, and this is a contributing factor to the development of crow’s feet and other facial wrinkling.
What Bone Conditions Does Jaw Surgery Improve?
Surgical procedures for the jaw, known as orthognathic surgery, is performed to treat jaws that don’t line up together when biting down, a condition that makes it difficult to smile, bite and swallow.
Jaws that aren’t aligned properly can result in pain TMJ as mentioned earlier. Certain cases of sleep apnea, people who duffer from a dry mouth, and have excessive tooth wear, may benefit from surgical bone procedures.
Birth defects are routinely corrected by performing orthognathic surgery.
Jaw surgery can also be performed for cosmetic purposes, and one procedure rising in popularity is square chin surgery.
Cosmetic Jaw Surgery and Square Chin Surgery
Men have wider, squarer and longer chins overall than females. Chin reshaping focuses on the underlying bones of the face. The procedure, known as sliding osseous genioplasty, can change the width of the chin and adjust the chin’s contours and height.
Chins that are too prominent, on the other hand, can be made to appear less so with this procedure. A recessed chin on the other hand can be made more prominent.
“Chin masculinization” surgery increases chin size, proportional to its current size. Men who believe they have less prominent, “weak” chins, are the best candidates for genioplasty.
How Have Jaws Evolved?
The basis of evolutionary research in the field of paleontology is comparing the genetic basis of early human development, about 3 million years ago, to more modern human genetics.
About 15 years ago, scientists discovered that a mutation of a gene surfaced that soon became dominant and replaced the earlier genetic makeup of man. The gene in question altered the muscles of the face and produced a smaller jaw, while making the brain larger in proportion.
This gene mutation may be what separates humans from apes, who didn’t undergo the same gene mutation. Our brains grew as our jaws grew smaller when the mutation appeared about 2 million years ago, so physical approaches to problem solving went down while mental processes increased. It is referred to as the “triumph of brain over brawn.”
The jaw of humans assumed a more refined contour, instead of jutting out. Teeth also become smaller because the jaw itself was smaller.
Along with a jaw comparatively graceful in appearance to the way apes’ jaws jutted out. Facial bones changed too, resulting in rounder, less square facial features.
There seems to be a relationship, then, between jaw size and intelligence, between hominid species of millions of years ago and modern man. A smaller jaw at the bottom of the face caused facial bones attached to the jawbone to become smaller, allowing more room in the cranium for a brain to grow and develop. It is fascinating to theorize about jaw sizes and intellect, and to wonder what mankind will look like in another 100,000 years.