Tag Archives: teeth

Why Is My Jaw Shrinking? The Dental Problems of a Western Diet

For 200,000 years before grain agriculture, the human jaw and the size of teeth were basically static. However, for the last 10,000 years or so, which coincides with the advent of agricultural farming, the width, length, and shape of the human jaw have been decreasing and changing slowly while the size of the teeth have changed very little.

So, what is going on?

Although genetics play a role, our environment has been the dominant contributor influencing poor jaw development. There appear to be three major external factors that are affecting the size and shape of our jaws. Two are the results of the onset of agricultural farming, and the more recent factor is the result of how babies are fed. They are:

  • Decrease in Nutrient-Dense Foods
  • Increase in Soft Foods
  • Decrease in Breastfeeding


Nutrient-rich food sources declined after agricultural farming provided a significantly increasing proportion of processed foods to our diets. The lack of necessary nutrients in the acellular carbohydrates of these grain and sugar products compromised bone metabolism.1, 2

Dr. Weston A. Price, a dentist, published Nutrition and Physical Degeneration in 1939. Price documented numerous observational examples of primitive peoples who had healthy dentitions and others who had various dental problems including gum disease, tooth decay, and poor jaw development. He identified that those with healthy dentitions generally ate nutrient-dense foods, and those with unhealthy dental conditions regularly consumed diets high in flour, sugar, processed vegetable fats and processed foods. Price implicated a lack of both fat-soluble vitamins and trace minerals to be the most important deficiencies causing dental problems.

Since then, there have been numerous observations among hunter-gatherer societies who had relatively healthy bodies with little or no chronic disease. Those hunter-gatherers who continued to eat their natural diets had healthy dentitions and those who left their traditional diets and began to eat a “western diet” developed dental problems and jaw shrinking and had offspring with increased dental abnormalities.3


Soft food sources, which reduced the physical stimuli on the jawbones and muscles of the jaw, increased after agricultural farming.

Processed grains and starchy foods provide a soft diet. Recent research has demonstrated that softer diets created less mechanical stimuli to the muscles and bones of the jaw resulting in a slow decrease in the density and the dimensions of the jaw over the course of time. Jaws didn’t need to be as strong or as large if the foods were less hard and less strenuous to chew. Rather than happening over an evolutionary time-scale, the change to the mandible was happening on an individual level as each child was growing up.4


Breastfeeding decreased after bottle-feeding became commercialized in the 1800s, which had a dramatic effect on the development of the jaw.5

Evidence suggests early humans breastfed until about three or four years of age. In the United States in 2011, 79% of newborn infants started to breastfeed. However, of infants born in 2011, 49% were breastfeeding at 6 months and only 27% were still breastfeeding at 12 months.6

Breastfeeding provides optimal oral mechanical stimulation for the jaw’s normal development. When infants breast-feed, they form a deep latch onto the breast. They open wide and take in enough breast so that the breast is pressing up against their palate. Babies do not merely “suck” the milk out, but instead they use their tongue in a U-shaped curve on the breast. In a wave-like motion they “milk” the breast to receive its nourishment. Two developmental actions take place: (1) a rhythmic action of the tongue “milking” the breast, which presses on the palate, and (2) the subsequent action of swallowing. Both actions play a critical role in proper stimulation and development of the dental arches, palate, jaw and muscles. As the baby grows, the breast continues to conform to the baby’s mouth.7

When bottle-feeding replaces breastfeeding, the unnatural nipple on a bottle does not fill or conform to the baby’s palate, and therefore does not stimulate any widening of the palate to ensure room for future teeth. Also greater suction forces are required during bottle-feeding. This forceful action causes the cheeks to draw in, putting pressure on the gums and alveolar bone, affecting the position of the teeth. As the baby grows, the bottle nipple remains constant and does not adapt to the developing mouth of a growing child, further compromising normal bone and muscle development


These are observational studies, and there is controversy about the significance of the factors I have discussed. But, eating nutrient-dense foods that represent the nutrition of our primal ancestors will enhance our body’s ability to do what it was designed to do. In addition, we should include raw foods as well as crunchy foods like nuts and seeds to stimulate and exercise the muscles and bones of the jaw. We need to chew our food thoroughly. Mothers should breast feed their children for as long as prudent. Our health and our children’s health are dependent on these primal and natural lifestyles.

Dr. Alvin DanenbergDr. Danenberg is a periodontist in South Carolina who has been in practice for 40 years. Within the last 4 years, he has included Laser Periodontal Therapy as his primary treatment for periodontal disease. The procedure is called “Laser Assisted New Attachment Procedure” or “LANAP”. The last two years he has incorporated a lifestyle program for all his periodontal patients including an ancestral diet to enhance their overall body’s health and function. In July of this year he was awarded the designation, “Certified Functional Medicine Practitioner.” For more information,  please visit www.DrDanenberg.com.



[1] Tucker KL (2009) Osteoporosis prevention and nutrition. Curr Osteoporos Rep 7:111–117

[2] Spreadbury I. (2013). Comparison with ancestral diets suggests dense acellular carbohydrates promote an inflammatory microbiota, and may be the primary dietary cause of leptin resistance and obesity. Diabetes Metab. Syndr. Obes. 5, 175–189

[3] Am J Clin Nutr March 2000 vol. 71 no. 3 665-667

[4] Sardi M, Novellino PS, Pucciarelli HM. 2006. Craniofacial morphology in the Argentine Center-West: consequences of the transition to food production. Am J Phys Anthropol 130: 333–343.

[5] Stevens EE, Patrick TE, Pickler R. A history of infant feeding. J Perinat Educ. 2009;18:32–39.

[6] CDC. Breastfeeding Report Card. Rep. Atlanta: Center for Disease Control and Prevention, 2014. Print.

[7] Palmer B. The influence of breastfeeding on the development of the oral cavity: a commentary. J Hum Lact 1998; 114:93-98.

The Perfect Teeth of Hunter-Gatherers?

Though there are many widely recognized benefits of The Paleo Diet, many people assume that modern dental advances likely improved our teeth. However, anyone familiar with the scientific literature, will know that, in fact, the exact opposite is the case. Hunter-gatherers exhibited low levels of dental caries, often had wisdom teeth that fit into their jaw, and, despite a complete lack of toothbrushes, toothpaste and dental floss – had good periodontal and gum health. How can this be? Well, in one word, the answer: carbohydrates. Or, more accurately, lack of carbohydrates.

Dental caries are also known as tooth decay, or cavities. One proposed mechanism, explained as simply as possible, is that bacterial and other acids in the oral environment can erode enamel and potentially initiate an inflammatory response in the dentin.1 So then, to avoid dental caries, mechanistically, it would make sense to limit bacteria and other acids, in your mouth. So how does one go about this? Well, a starting place is limiting sugar.2 The high prevalence of dental caries in recent times is directly attributed to more frequent consumption of plant foods rich in fermentable carbohydrates,3 as cannot be overstated, since caries are increasingly common, worldwide.4

Scientists have long theorized that when hunter-gatherers moved towards agriculture — and subsequently changed their diet, that this affected the development of the skull and jaw.5 Along with this change, came a well-documented rise in dental caries.6 The ancient Egyptians are an interesting case to look at, for example. Although dental caries are commonplace in today’s society, ancient Egypt lacked caries, for the most part, due to the lack of fermentable carbohydrates in the diet.7 Another factor would be the fiber in their diet, which helped to avoid some plaque retention.8 Then we have the case of the Hardin Villagers. They had rampant tooth decay, due to their high carbohydrate diet.9

However, there are some studies that conflict this observation. For example, this study10 shows that starchy foods may have led to high rates of tooth decay in Morocco – several thousand years before the dawn of agriculture. But dental caries are not the only issue here. Research shows that hunter-gatherers had consistently longer and narrower mandibles than those practicing agriculture.11 Then there is the observation that hunter-gatherers developed flatter molar wear due to the mastication of tough and fibrous foods.12 Agriculturalists develop oblique molar wear, which is a result of an increase in the proportion of ground and prepared food which they consume.13

Another interesting observation, is that dental caries aren’t unique to humans. Evidence for caries has been seen in Paleozoic fish, which lived 570 million years ago.14 A review of populations throughout time, shows that hunter-gatherers, as a whole, show roughly a rate of 0-5% of dental caries.15 That is astoundingly low, especially when compared to modern day populations. Today we roughly experience a rate of 92% of dental caries,16 and that percentage is only a survey of those with teeth left.

So, what is the best way to avoid dental caries? A diet low in sugar, and subsequently carbohydrate, like the Paleo Diet, would be a great idea. The literature shows obvious links between dental caries and fermentable carbohydrate ingestion.17,18 Though hunter-gatherers may not have needed them, good oral hygiene would be a good idea as well. And it is interesting to note, that different refined items, such as wheat, corn and sugar, may produce different rates of dental caries.19 Avoid all three, and you are well on your way to dental perfection, like your ancient ancestors may have had.


1. Southward K. The systemic theory of dental caries. Gen Dent. 2011;59(5):367-73.

2. Touger-decker R, Van loveren C. Sugars and dental caries. Am J Clin Nutr. 2003;78(4):881S-892S.

3. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;:201318176.

4. Bagramian RA, Garcia-godoy F, Volpe AR. The global increase in dental caries. A pending public health crisis. Am J Dent. 2009;22(1):3-8.

5. Available at: //www.history.com/news/for-perfect-teeth-start-hunting-and-gathering. Accessed June 16, 2014.

6. Dental anthropological indications of agriculture among the Jomon people of central Japan. X. Peopling of the Pacific. American Journal of Physical Anthropology. 51(4):619.

7. Dental health and disease in ancient Egypt. British Dental Journal. 2009;206(8):421.

8. Rateutschak-Pluss E M, Guggenheim B. Effects of a carbohydrate-free diet and sugar substitutes on dental plaque accumulation. J Clin Periodontol 1982; 9: 239–244.

9. Cassidy CM. Nutrition and health in agriculturalists and hunter-gatherers: a case study of two prehistoric populations. in Nutritional Anthropology. Eds Jerome NW et al. 1980 Redgrave Publishing Company, Pleasantville, NY pg 117-145

10. L. T. Humphrey, I. De Groote, J. Morales, N. Barton, S. Collcutt, C. Bronk Ramsey, A. Bouzouggar. Earliest evidence for caries and exploitation of starchy plant foods in Pleistocene hunter-gatherers from Morocco. Proceedings of the National Academy of Sciences, 2014

11. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;:201113050.

12. Smith BH. Patterns of molar wear in hunger-gatherers and agriculturalists. Am J Phys Anthropol. 1984;63(1):39-56.

13. Klaus HD, Tam ME. Oral health and the postcontact adaptive transition: A contextual reconstruction of diet in Mórrope, Peru. Am J Phys Anthropol. 2010;141(4):594-609.

14. Luis Pezo Lanfranco and Sabine Eggers (2012). Caries Through Time: An Anthropological Overview, Contemporary Approach to Dental Caries, Dr. Ming-Yu Li (Ed.), ISBN: 978-953-51-0305-9, InTech, DOI: 10.5772/38059.

15. Forshaw R. Dental indicators of ancient dietary patterns: dental analysis in archaeology. Br Dent J. 2014;216(9):529-35.

16. Raner E, Lindqvist L, Johansson S, et al. pH and bacterial profile of dental plaque in children and adults of a low caries population. Anaerobe. 2014;27:64-70.

17. Guggenheim B, Ben-zur E. [Fermentable carbohydrates in teething preparations as a cause of caries in small children]. Schweiz Med Wochenschr. 1982;112(7):232-4.

18. Bokhout B, Hofman FX, Van limbeek J, Prahl-andersen B. A ‘sufficient cause’ model for dental caries. J Epidemiol Biostat. 2000;5(3):203-8.

19. Utturkar SM, Klingeman DM, Land ML, et al. Evaluation and validation of de novo and hybrid assembly techniques to derive high quality genome sequences. Bioinformatics. 2014;88(6):490.

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