In 2005, Christopher Wild noticed that researchers were too genome-centric and needed to look at other disease causes. The studies of individual genes linked to certain conditions did not result in much progress against those diseases. He recognized "a desperate need to develop methods with the same precision for an individual's environmental exposure as we have for the individual's genome." So he wrote an editorial for the American Academy of Cancer Research, suggesting researchers consider more than just our genome in their quest to combat cancer and other diseases. Wild proposed the term "exposome" to represent life-course environmental exposures from the prenatal period onwards. 1

Our Genes Are Less Important Than Our Environments

Genomes provide the blueprints, but, in fact, it is our environments that determine what we become. Lifestyles, diet, toxins, stress, relationships, socioeconomic status, pathologic germs, climatic conditions, etc., play a much more significant role than our genome. In fact, up to 90% of all diseases are due to the exposome. 2 

Measuring The Exposome

Developing reliable measurement tools for such a complete exposure history is exceptionally daunting. Furthermore, unlike the genome, the exposome is complexly dynamic and varies throughout a patient's life. Thus, even simple events like exposures to toxins present problems. Fortunately, many new technologies make it possible to obtain detailed information on drugs, toxicants, pollutants, nutrients, and physical and psychological stressors as part of the exposome. 

Since everyone's disease is the product of the personal history of exposures, superimposed on their underlying genetic susceptibilities, properly constructed models based on the exposome may eventually explain these biography-to-biology transformations. 3 We are already piecing together more appropriate disease models through more rigorous examination of biological samples, better questionnaires, new biological assays, toxin detection, biochemical trace detection, and more. The task is daunting and will ultimately involve the combined efforts of every scientific discipline.

The HELIX Project

Early life and prenatal developmental periods are particularly vulnerable to environmental exposures. Unfortunately, human research has generally focused on single exposure–health effect relationships. The Human Early-Life Exposome (HELIX) project is a mammoth attempt at piecing together the complex exposome of prenatal and childhood development to understand how to raise healthy children. They plan to study 32,000 mother-child pairs over 18 years. The researchers plan to review numerous blood test markers, monitor physical activity via smartphone technology, and monitor personal exposures to climate and toxins. Additionally, countless other lab tests will determine molecular profiles associated with exposures. The end goal is to develop algorithms of exposure-response estimates for fetal and child growth, obesity, neurodevelopment, and respiratory outcomes. 4 

The Craniofacial Exposome

I have written at length about some of the things that can influence facial development on this site. Of course, genetic problems like Pfeifer syndrome and trisomy 21 happen and can have drastic effects on the ultimate shape of our faces and heads. Still, most of the determinates of the form our faces and skulls take are influenced by our environment. We still have a way to go in our definition of the craniofacial exposome, but here are some things we are beginning to understand and incorporate into our diagnoses and treatment.

Tongue-tie (Ankyloglossia), Also Called Tethered Oral Tissues

 When the connection of the tongue below our lower front teeth, called a frenum, is too short, limitations on the movement of the tongue arise. The tongue must sit firmly on the roof of the mouth when we are not eating or speaking. If it can't, the dental arch will not develop properly. Breastfeeding problems are also a concern with tongue ties, as swallowing can be compromised. Later in childhood, GERD may arise due to swallowing air with each mouthful. Luckily, most neonatologists and pediatric dentists check for this condition, and it is easy to fix with a quick laser procedure.

Exposure to Microbes, Parasites, and Germs

It has been long known that areas of the world that experience parasitic infections suffer from fewer allergies. 5 Additionally, the hygiene hypothesis describes the decreasing incidence of infections in western countries and, more recently, in developing countries, the increasing incidence of both autoimmune and allergic diseases. In other words, exposure to germs calms the immune system and lowers the chances of developing allergies. 6 Allergies can significantly impact facial development, especially when allergic rhinitis (stuffy nose) is a symptom. When our noses are inflamed, breathing through the mouth sometimes becomes the only way to get oxygen. Having an open mouth while sleeping is another way that the tongue will be taken from its natural position on the roof of the mouth. When in the correct posture, the tongue is mainly responsible for enlarging the dental arch and flattening the palate. Hence, allergies can result in narrow arches and high palatal vaults in many cases. Since allergies can be detrimental to facial growth and development, allergists are indispensable for a comprehensive airway team.

Breastfeeding

Mother's milk provides the perfect nutrition for newborns.  In addition, breastfeeding also helps correct orofacial development. 7 The explanation is a bit complex, but the primary mechanism involves the unique swallow pattern newborns demonstrate and the shape of the human nipple. Obviously, any variation in this arrangement can have adverse effects on facial growth. Some reasons suckling may be altered are tongue-ties, distortions in oral muscle tone, poor maternal lactation, and trauma to either mother or infant. Today, bottle feeding has become all too common, and we see the detrimental effect it has. Astonishingly, 90% of children born today will have poor facial development by age 5, and 90% of those are bottle-fed. 8 So, other breastfeeding-related issues revolve around so-called non-nutritive habits and bottle feeding. These include pacifiers, thumb and digit sucking, and early weaning. Most investigations into breastfeeding patterns conclude that children will naturally breastfeed up until the age of three. Therefore, the obvious course to take for optimal facial growth revolves around proper breastfeeding.

Food Consistency

Our foods have become increasingly softer since we began farming over 10,000 years ago. It turns out that bone grows best when placed under strain. Dr. Melvin Moss was one of the first to notice this. He called it the functional matrix hypothesis. 9 John Mew and his son Mike have developed a system that includes hard chewing to promote beautiful faces. You can see John talking about it here. Part of the problem revolves around our fear that toddlers will choke on hard foods during weaning. Compounding the issue is the introduction to spoon-feeding, which introduces improper swallowing, another cause of facial malformations. The transition to normal swallowing takes place at twelve to eighteen months. So early spoon-feeding can prevent normal swallowing; in turn, poor swallowing can trigger undesirable facial growth. 10 The cure for this problem is simple, chew hard foods.

An example is leaving the hard ends of asparagus on with your child's meal. It will require much more time and effort, thus stimulating proper facial development. There is a unique hard gum called mastic gum that can also help. It is so tough that our teeth don't meet and wear as they would with traditional gum. You can purchase it online.

Posture

Numerous studies show a connection between posture and craniofacial growth patterns. The mechanisms are still being worked out, but the idea is that the skin and muscle stretch with incorrect posture exert forces on the jaw, causing anomalies in growth. Solow and Kreiborg simply called this the soft tissue stretching hypothesis. 11 The effect is somewhat bidirectional. For example, if it is hard to breathe because of small jaws, a forward head posture may help. On the other hand, a forward head posture will cause alterations in facial growth. A forward head posture generally results in a longer face, while a head-back posture, which is less common, results in a shorter face with a protruding chin. 12 Correct posture is critical for normal jaw development, and in this day and age, when our children are constantly looking down at their computers and phones, it is not happening.

Beds And Pillows

Michael Tetley has postulated that sleeping in beds and using pillows may cause incorrect oral postures resulting in facial deformities. His observations need further investigation, but he notes how primates and other animals sleeping on hard ground resets the posture and diminishes orthopedic problems, including oral posture. His paper on how to sleep is now over 20 years old but well worth a look. You can read it here.

The aspects of the craniofacial exposome I covered today are by no means exhaustive. As researchers continue to look at craniofacial growth, more connections will be made. For example, Dr.'s Boyd and Evans observe that the lack of oxygen in the womb from mothers who smoke or have apnea can cause small retruded lower jaws (retrognathia). Hopefully, you have taken away something helpful from this post that can help a child in your life realize their birthright to grow a perfect face. Below is a comprehensive comparison of exposures that have influenced poor jaw development. It is from a paper entitled The Jaw Epidemic: Recognition, Origins, Cures, and Prevention.