Facial dwarfing and dental crowding in relation to diet

Abstract

A simple framework is offered here for relating dental function, particularly the size of the dentition and its supporting skeleton, to the rest of the mammalian body. Built up from a simple understanding of the fracture properties of foods in mammalian diets, it predicts that mammals that reduce their body size rapidly will have jaws that become too small to house all their teeth. Dental overcrowding, with eventual reduction in tooth size or reduction in tooth number, is a logical result. The Flores finding shows a dentally crowded jaw entirely consistent with this theory. However, the theory also predicts that reduction in the values of certain mechanical properties of foods, particularly their toughness, will also bring about similar trends without changing body size. Dental crowding in modern humans is considered the combined result of tool use to comminute foods and cooking to modify their mechanical properties, such as toughness.