Table 1.

Changes in the orofacial-respiratory environment induced by agricultural revolution and industrialization, with possible impacts on oral posture and jaw development and health.

Hunter-gatherer societies (physical development focus)	Industrialized societies (intellectual development focus)
Long breast feeding, specialized muscle use	Insufficient nursing to develop posture or to hold muscle tone
No bottle feeding, normal physiological delivery	Strong milk flow in bottle feeding, spoon feeding disrupts normal swallowing, Pacifiers and bottle nipple changing tongue posture
Wean to adult diet, baby learns what and how to eat	Baby food, pap, spoon feeding disrupts self-learning
“Chewy” diet, and proper swallow, encourages salivation (PH, cleaning, remineralization, first digestion, etc.)	Increasingly liquid diet, bypasses positive nutritional and developmental effects from vigorous chewing, salivation
Sparse populations, less viral transmission, fewer stuffy noses	Dense populations, more nasal blockage, lead to hanging mouth open at rest
Much time spent outside, less allergen exposure	Little time spent outside more exposure to concentrated allergens
Sleeping on the ground, head not pillowed	Sleeping on a mat or bed, head pillowed
Sleep relatively exposed to predators or enemies, snoring selected againsta	Sleep securely indoors, snoring less lethal
Body, nasal breathing and general posture maintained	Body, nasal breathing and general posture often ignored
Active outdoor living, mouth closed, predominantly nose breathers, tongue plastered on palate and teeth lightly together at rest a	Couch potato, cell phone addict, teeth kept mostly apart at rest, nose frequently blocked, mouth often hung open, tongue held low partially resting over teeth kept apart

Note: Environmental changes possibly influencing jaw development in modern societies. Italic text represents the correct posture to provide an environment for normal jaw development. ^aSpeculative.