Those who’ve read the scientific literature on Paleo and/or spent some time scouring through ancestral health blogs online are well aware of the fact that colon cancer, type-2 diabetes, obesity, and many other chronic health disorders we suffer from in today’s society are rare or virtually nonexistent among hunter-gatherers and traditional people who are largely unaffected by modern lifestyle habits.
What is sometimes forgotten is that it’s not just the prevalence of cancer, cardiovascular disease, and other diseases that are among the leading causes of death in the modern world that have skyrocketed since our hunter-gatherer days, but also the rates of many health conditions that are of a more superficial nature and are generally considered relatively harmless to one’s health, such as malocclusion, myopia, acne vulgaris, and impacted wisdom teeth.
HUNTER-GATHERERS HAD BROAD DENTAL ARCHES AND AMPLE ROOM FOR WISDOM TEETH
Studies show that hunter-gatherers and traditional, non-westernized people generally have broad dental arches, ample room for wisdom teeth, and ideal or close to ideal occlusion (the manner in which the upper and lower teeth come together when the mouth is closed).1-3,5 The fact that these same characteristics are seen in skulls of Paleolithic humans further supports the notion that this condition is the evolutionary norm for our species.3
This is in stark contrast to modern societies, where conditions such as malocclusion, impacted wisdom teeth, and narrowed dental arches are extremely common. In his excellent talk at the 2012 Ancestral Health Symposium,4 Dr. Mike Mew, a London-based orthodontist, suggests that the underlying cause of all of these issues is a syndrome called Craniofacial Dystrophy; a condition characterized by a downswing in the anterior craniofacial structure (ACS).
He highlights the severity of today’s situation by pointing out that 50% of all wisdom teeth are removed and that approximately 95% of the population in industrialized nations has deviations in their dental alignment. Of these 95%, approximately 30% are recommended orthodontics treatment, a treatment that improves the symptoms present, but may actually worsen the underlying problem.
Modern faces are “melting down” in the sense that there has been a major change in the human skeleton since the Paleolithic era. Over the last few thousand years – a blink of an eye from an evolutionary perspective – human faces have become approximately 5 to 10 % smaller after correcting for body size.3
Some would argue that beauty is in the eye of the beholder and/or that culture is the main factor involved in determining what we perceive as aesthetically pleasing. However, we also have to remember that we have evolved an attraction to certain features as a way to distinguish the healthy and virile from the weak.
Physical attractiveness can serve as a biological signal of good health, and we probably find people with well-developed faces, strong jaws, and broad dental arches attractive because these features are indicators of good genetic qualities and health.
Besides being aesthetically unappealing, the change to a longer, thinner craniofacial structure has had important implications for how we breathe, chew, and function.
How did we get ourselves into this mess?
MALOCCLUSION, CROWDED TEETH, AND NARROW DENTAL ARCHES ACCOMPANY THE ADOPTION OF MODERN DIETS AND LIFESTYLES
Studies – such as those carried out by researchers like Dr. Robert S. Corrucini, who campaigned the idea that malocclusion is a disease of civilization, and Dr. Weston A. Price, who documented the health condition of isolated, traditional populations before and after westernization – show that people who transition from a traditional lifestyle and nutrient-rich, whole foods diet to a western lifestyle and nutrient-poor, processed diet experience a rapid decline in health.1,5 Moreover, children who are born and raised in the “westernized environment” have a high prevalence of malocclusion, crowded teeth, and tooth decay.1,5
While some traditional populations who undergo westernization seem to be more susceptible to the so-called diseases of civilization than others, the consistent nature of these findings clearly shows us that nobody is immune to the adverse health effects associated with a Western lifestyle.
A study of younger Australian Aborigines whose families recently started eating processed, modern foods is one of the many examples of cases where these effects are seen. This study found that the younger family members had smaller jaws and serious tooth crowding problems compared to elder members of their families who grew up eating traditional food.1
WHY DON’T MODERN FACES GROW AND DEVELOP NORMALLY, AND HOW CAN WE TURN THINGS AROUND?
Weston A. Price suspected that insufficient intake of fat-soluble vitamins, in particular vitamin A and D, was the main cause of dental arch deformities among people who had transitioned from eating a traditional diet – which tends to be high in organ meats and other nutrient-dense whole foods rich in fat-soluble vitamins – to modern food ways. However, there is little concrete evidence in support of this hypothesis.4 Rather, the evidence suggests that the main causes of malocclusion, crowded teeth, and/or narrow dental arches are as follows:
USE OF THE MASTICATORY SYSTEM
In the blink of an eye from an evolutionary perspective we’ve moved from eating a hard, fibrous, and low-calorie density hunter-gatherer diet to a soft, processed, and high calorie density modern diet, something that has had a profound impact on our occlusion, teeth alignment, and craniofacial development.
Compared to our Paleolithic ancestors – and to a lesser extent Neolithic farmers – most people today only put in a small fraction of the chewing effort needed to gain calories. This also includes those who eat a whole foods diet (including contemporary Paleo dieters), as the plant foods you find at the typical supermarket today tend to be markedly lower in fiber when compared with uncultivated varieties. Also, many of us grind, blend, cook, or otherwise soften a lot of the food we eat.
Not only that, but we no longer use our teeth as tools (e.g., to make clothes), something that has further contributed to a decrease in the amount of stress put on the jaw musculature.
There is strong evidence to suggest that reduced use of the masticatory system is an important cause of malocclusion, impacted wisdom teeth, narrow dental arches, and other symptoms of Craniofacial Dystrophy.2,3,6
We need to toughen up our diet – and in particular, the diet of growing children!
MATERNAL AND CHILDHOOD NUTRITIONAL STATUS
Maternal nutrition plays a critical role in fetal growth and development, with sufficient intake of vitamin k2 being especially important for proper development of the jawline.2
In traditional populations, nutrition of couples prior to pregnancy and of women during pregnancy and lactation was generally given more importance than it is in today’s society, and nutrient-dense foods such as organ meats were considered essential for producing healthy children.
Nutritional status during the childhood years is also known to impact the growth and development of the child, but as there are few studies directly related to malocclusion and other problems associated with Craniofacial Dystrophy, it’s difficult to draw firm conclusions in this area.
SUCKING HABITS AND “ORAL POSTURE”
In his excellent series of articles titled “Malocclusion: Disease of Civilization,”2 Dr. Stephan Guyenet brings up convincing research which shows that pacifier sucking and bottle-feeding can cause weak jaw muscles, abnormal development of bony structures, and malocclusion. Breastfeeding on the other hand has a protective effect against malocclusion, most likely because it promotes proper palate formation and improves nutritional status.
Orthotropics is a form of natural orthodontics that is based on the idea that ideal development of the face and jawline is dependent on correct “oral posture.” In his 2012 AHS talk, Dr. Mike Mew makes the case that correct posture should be with the tongue resting against the palate, with the lips sealed and the teeth in or near contact.
There is strong evidence to suggest that malocclusion, narrow dental arches, and several other conditions associated with poor facial growth and development are manifestations of a gene-environment mismatch. Adopting a Paleo-inspired lifestyle – with a particular emphasis on masticatory effort and usage (especially for growing children), maternal and childhood nutrition, “oral posture,” and infant sucking habits – is the natural solution to resolving this conflict between our ancient genome and our modern diet and lifestyle.
 R. S. Corruccini, ‘An Epidemiologic Transition in Dental Occlusion in World Populations’, Am J Orthod, 86 (1984), 419-26.
 Stephan Guyenet, ‘Malocclusion: Disease of Civilization ‘2009) <http://wholehealthsource.blogspot.no/2009/09/malocclusion-disease-of-civilization.html>.
 Daniel Lieberman, The Story of the Human Body: Evolution, Health, and Disease (Vintage, 2014).
 Weston A. Price, Nutrition and Physical Degeneration 8edn (Price-Pottenger Nutrition Foundation, 2008).
 N. von Cramon-Taubadel, ‘Global Human Mandibular Variation Reflects Differences in Agricultural and Hunter-Gatherer Subsistence Strategies’, Proc Natl Acad Sci U S A, 108 (2011), 19546-51.