Square Jaws and Exceptional Beauty, Is it genetic or jaw usage?

Found an interesting site that promotes the connection between horizontal, square jaws to exceptional facial beauty in women. An insight into what causes this development, is it a key to facial beauty?

 

 

http://www.womenlargejaw.com

“It is my goal on this site to analyze female beauty, and to defend the idea that square jawed females are of a superior class of beauty than other females, and that this attribute is not always correlated to masculinity / femininity but rather to proper / optimum orthodontic development. ”

I agree with many of the points on this site, while women can be beautiful without square jaw, the superior beauty of models is most always accompanied by a very impressive horizontal lower jaw.

Importance of Square Jaw in Advertising

“Square jaw admirers should pay attention to advertising from eyeglasses companies. It is almost a mandatory requirement for this kind of product ads to feature models with heavy, square facial structures. Why ? Because strongly structured faces look much better with object ornament like glasses than would thin faces and the disproportionately small and underdeveloped appearance they would project . Broad faces allow all kind of glasses shapes and sizes while still looking cool.”

I think the women on this site is most closely approaching what Dr. Mike Mew referred to as his “perfect, ideal faces”.

The big question is did these women inherit these jaws (pure genetics) or is there something else?

The theory on the site of square jaw is genetics but I think as site author’s research deepened he found more and more evidence of connection between muscle tone and jaw development.  As below page on the site suggests.

The Muscle Factor

On the site there is an interesting page where the author of the site has collected various articles of study that show the muscle effect on jaw development. http://www.womenlargejaw.com/bite-force

below are some of passages that stood out for me.

Strong – and weak – muscle factors
Why are these differences in mandibular morphology important? In horizontal growers, the angles at which the muscles work produce much masticatory force. In vertical growers, the angles at which the muscles work produce much less force.12 Therefore, horizontal growers can be referred to as strong-muscled patients, and vertical growers can be referred to as weak-muscled, patients. In Figure 5, the morphological differences are highlighted between the two growth patterns as viewed on lateral cephalometric x-rays. The morphological differences are numerous, but five are especially diagnostic.

First, strong-muscled patients have relatively acute gonial angles; in weak-muscled patients, the gonial angle tends to be obtuse.13, 14 Second, the shape of the lower border of the mandible differs in the two types of patients. In strong-muscled patients, a double curvature on the lower border consists of a concavity near the gonial angle and a convexity near the anterior portion of the lower border. Weak-muscled patients lack this double curvature and instead exhibit a concave lower border. Third, strong-muscled patients have a radiopaque symphysis; in weak-muscled patients, this area is more radiolucent.2 Fourth, the more acute the symphyseal inclination, the more the patient tends to be strong-muscled. This can be quantified by a simple cephalometric measurement of the angle between Go-Gn and the chin line (the line from pognion (Po) to infradentale (Id) – the most anterosuperior point on the mandibular alveolar ridge) (Fig. 6). 11 A range of 70° ± 4° is normal: 65° or less indicates that the patient is strong-muscled; 75° or more indicates that the patient is weak-muscled

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Wolff’s Law (1949) states that, “Every change in the use or static relations of a bone leads not only to a change in its internal structure and architecture but also to a change in its external form and function.” Given that the masseter and the medial pterygoid muscles are the principle muscles of mastication enclosing the angle of the jaw, it is postulated by the authors that the bony morphology underlying the gonial angle may provide a reliable expression of the inherent muscular biting power of any individual. A larger muscular force would theoretically produce a more acute angle and a weaker force a more obtuse one.

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ISOMETRIC BITE FORCE AND ITS RELATION TO CRANIOFACIAL MORPHOLOGY
Taek-Woe Lee, Ki-Soo Lee
This study was undertaken to grope the correlation of the maximal bite force and tooth craniofacial structure. The maximal bite force of 76 adult male, aged 18-28 (mean aged: 23.4 ±2.2) years, was estimated and cephalometric headplates were measured, tabulated and statistically analyzed.

The bite force was negatively correlated to genial angle, mandibular plane angle, the angle between occlusal plane and mandibular plane, the angle between palatal plane and mandibular plane, and positively correlated to posterior height of face, length of mandibular body,length of ramus, facial depth in craniofacial structure.

(Note: posterior height of face means back of the face, so longer ramus. which is a good thing for facial aesthetics, what you don’t want is lengthening of front of face, or anterior facial height. reference above picture)

Again above study shows that people that have more horizontal, longer jaws have more developed muscles. This study seems to suggest that it is the absolute biting force of the jaw muscle that is important for proper facial development, however this area of study is still not conclusive and this could be misleading.
if we are talking about changing the shape of our bones in the face then it is not the absolute strength of muscle that is important but the usage of muscle that has the lasting effect on facial morphology.

So if we are talking about body building terms, reps are more important than short, high weight training. Please view Dr. Mike Mew’s statements below.

“Ideally we are trying to strengthen *mouth* closing muscles. Also the strange paradox is that it is the level of usage of a muscle rather than its absolute strength that is important. If you exercised very hard with your jaw muscles for 3hrs a week but then did not use them at all the rest of the week, you might have a high maximum bite force but your face may still lengthen. This does complicate research on the area and is one of the reasons that this is not a well understood area. I would recommend a tough chewing gum, we are trying to source and develop one at the moment. Best wishes, Mike”

LInk to the Toughest chewing gum I have found so far, and I do over 3 hours of chewing daily.

Now my theory is that people with better developed faces most likely will have higher biting force since they are doing more chewing on a daily basis to have stronger muscles. Since chewing really is the only form of exercise we have for our jaws, and I don’t think anyone is out there training their jaw muscles with weights.========

Tearing flesh from the bone in the absence of knives tends not.only to strengthen the masseter muscles and enlarge the zygomatic arch somewhat as a direct consequence,
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In the skull there’s this thing called the zygomatic arch, which is behind the eyes, and your jaw fits in there, and if you have a really big zygomatic arch, then that means that a lot of muscle is in there

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The cheekbones and jaws of the Eskimo are very massive, possibly under the influence of the intense chewing he has to practice, which also results in a tremendous development of the chewing muscles. Eskimo teeth are often worn down to the gums, like animal teeth, from excessive use.

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Two groups of men with opposite facial morphology were then selected: all men with a steep mandibular plane (higher than the mean plus one standard deviation) entered a first group (10 ‘long face’ subjects), while all men with a relatively more horizontal mandibular plane (lower than the mean minus one standard deviation) entered a second group (13 ‘short face’ subjects). Mean EMG potentials computed in the two groups were compared by using Student’s t -test for independent samples. All the EMG potentials recorded during maximum voluntary clench in the ‘long face’ men were lower than that recorded in the ‘short face’ men, with statistically significant differences for all four analyzed muscles (p < 0.05). In conclusion, a non-invasive three-dimensional method confirmed that facial morphology and muscular function are significantly related, at least in men with a sound stomatognathic apparatus.

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Since they do not chew on hard foods, the cheek and jaw to which the chewing muscles attach will recede. If the cheekbone recedes, it will not stick out, so people’s faces will get much narrower. In addition, the lower jaw will become thin. The area from the eyes to the cheeks, and up to the mouth will become more narrow, and recede back into the face.

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It was remarked in a
former chapter that as man gradually became erect, and continually
used his hands and arms for fighting with sticks and stones, as well
as for the other purposes of life, he would have used his jaws and
teeth less and less. The jaws, together with their muscles, would then
have been reduced through disuse, as would the teeth through the not
well understood principles of correlation and economy of growth; for
we everywhere see that parts, which are no longer of service, are
reduced in size.

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The Zygomatic Bone

In addition to the square jaws, these models have this impressive cheekbone, the zygomatic bone is very well developed. This bone is connected to the maxilla and forward placement of the maxilla should give this bone more prominence however what gives it its striking prominence may have to do more with the effect of the the masseter muscle on this bone. Since the masseter connects directly to this bone, an individual that chew considerably more would need this bone more further developed to be able to handle the stress of chewing and increase of masseter muscle mass. We all know stress stimulates activity of osteoblast and osteoclasts, to create new bone growth. Think about it, if the zygomatic bone didn’t grow bigger, stronger, and sturdier the it would not be able to resist the great upward force of chewing, the bone would collapse into the eye sockets.

Picture on the left also shows where this muscle attaches to the lower jaw. Right where the gonial angle of the jaw is and where the jaw is determined to be horizontal or vertical. If this muscle is strong than it is hard to imagine a big gonial angle, it would seem that the muscle would crush the jaw and make that angle closer to (horizontal) 90 degrees over time.

It is interesting to note, that I personally have more developed left side of the face. The zygomatic bone on left side is more developed and wider/bigger, and left side of the face looks better than the right in comparison as the right side is more flatter and the cheekbones are less defined and smaller. Most people often have their more photogenic side of the face.

I have been trying to resolve this asymmetry through self-NCR, palate expansion, face pulling which was helping to some degree the position of these bones but the actual size and definition of the bones weren’t equalizing, what I have made noticed was that I had habitual habit of chewing on the left side, to the point where if I tried to chew on the right side (underdeveloped side) it felt awkward and weird. This shows that I hardly ever chewed on my right side and could explain the differences in development. I have since then began chewing more on the right and starting to seeing its subtle effects. Also I was more accustomed to sleeping on the right side of the face which may have some effect as well. I am beginning to balance a lot of this out.

It is still too early to tell, but resolving facial asymmetry, I have missed 1 crucial factor that is the effect of the chewing force on the facial bones, and the effect of uneven chewing may have on facial symmetry.

Interesting case study on womenlargejaw.com

http://www.womenlargejaw.com/square-jaw/scan

This square jaw women had CT scan showing pretty much 90 degree gonial angle. Very rare and perhaps sign of over development of the masseter muscle.

did she inherit these impressive jaws? or were they developed by muscle usage?  I read through the page to find clues and sure enough I found signs of excessive usage of the masseter.

“Large muscle attachment, strong bite force that can cause headaches”

she wrote in the comments, “The CT scan was necessary to study a treatment because this angle and the strong muscles in my jaw causes strong headaches sometimes, together with some other odontological problems. All because I have a really strong bite and, since my muscles are “used” to it, I just notice when it’s too late and painful”

“Last year I’ve done a cosmetic treatment with porcelain veneers to restore the shape of my teeth. Since I have a really strong bite and had bruxism in the past, they’re ‘flat’, as you can see in the CT scan.

And no, my wisdom teeth hasn’t been extracted.”

There you have it, she had bruxism as a child, which is a condition of habitual teeth clenching and grinding unconsciously often times during sleep all night long, many people suffering from this same condition often show similar jaw development.

Below picture of her as a child shows that the jaw size was already there before introduction of growth hormones from adolescence.

In conclusion, this case study again illustrates that jaw bone develops depending on usage.

Effect of Testosterone and Jaw size?

http://www.womenlargejaw.com/square-jaw-is-not-masculine : pretty good read on why there is no correlation between testosterone and square jaws.

“Squareness of jaw isn’t determined by androgenic hormones. There are very feminine women with very square jaw, and very masculine men with non square jaws. Yet, these men always have more serum testosterone and growth hormone circulating in their body.
Androgenic hormones can affect bone extremities growth, and although big chins and jaws can be the result of these hormones influences, a “manly” jaw isn’t characterized by the angle of the jaw itself. Manly jaw is rather characterized by bone mass at extremities which give typical virile shape to chins, massetter attachments and other subtle traits that would deserve another article.”

Another example of masculine face with no square jaws.

Conclusion

Jaw size and development, seems to develop according to its usage rather than predetermined by genetics. It seems that the masseter muscle has a large influence on the zygomatic bone (cheek bone) and mandible (lower jaw).

Our Ancestors had great set of jaws: imagine the difference in jaw work out if you’re trying to get full on a bag of beef jerky versus a plate of pasta. Try it out and see how much of difference it is… It is no wonder that the horizontal jaw is such a rare phenomenon these days, how were the models able to develop it in this modern environment?  It would be interesting to interview them and get an insight into their childhood diet and habits… I suspect many of them had some habit of clenching their teeth or gritting their teeth throughout life as form of dealing with stress or etc. I remember I accidently found a blog of a Chinese super model when I was researching about bruxism, and this model was getting botox shots in her jaws because she was a chronic teeth clencher which gave her bad headaches… makes me wonder was her well developed face as a result of her teeth clenching? I think there def is a connection there.

Now can we change the shape of adult jaws that have supposedly already stopped growing, just by beginning to chew more?

This is the million dollar question, and attempting to answer it is not an easy over night process, one would need serious commitment and determination. We are talking again changing the whole environment of an individual to that of requiring massive amounts of chewing daily.

I am up for the challenge to put these theories to test… It is tough to revert our diet to eskimo diet but I believe I can compensate by using tough chewing gums. Time to start chewing…

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-cp