Developmental, evolutionary and behavioural perspectives on oral health

Teeth provide myriad information about human development, evolution and behaviour. This begins with birth—one of the most profound physiological shifts that we all record in our teeth. Subsequent daily records of enamel growth reveal the timing of developmental insults and infections during childhood. Nutrient deficiencies may also show up as structural defects in crowns and roots. Permanent microscopic marks and chemical records are important for understanding the health of past peoples, including our hominin ancestors, as is an understanding of the evolution and changing ecology of our oral microbiome. Scholars are also working to understand the developmental and evolutionary bases of dental diseases and disruptions, such as the failure of third molars to form or to erupt—both of which are common in recent humans, but less so during our deeper past. Evolutionary medicine holds that contemporary dental diseases such as caries and periodontal disease may relate to fundamental changes in our behaviour, especially our diet. Finally, hunter-gatherers give us important clues as to why our ancestors did not need orthodontic treatment as so many of us now do. Soft processed diets beloved by modern children and adults alike are insufficient to stimulate jaw growth, leading to skyrocketing rates of impacted wisdom teeth, dental crowding and possibly even novel speech production.