Organic tooth wear--overlooked in anatomy texts.

Most anatomy texts depict gear-like apposition of adult upper and lower teeth. But this apposition generally does not occur in civilized man. On the contrary the widespread tooth attrition which occurs in primitive man, is well established. This attrition, which is not depicted in anatomy texts or correctly evaluated in medical and dental education, is a natural protective mechanism that functions to preserve, oral, pharyngeal, and respiratory physiology throughout life. As man removed grit, sand and other abrasive food from his diet, he deprived himself of a natural aid, i.e. attritional wear of teeth that protects the physiology of his mouth and the swallowing and respiratory apparatus (4). In contrast to this the unworn teeth, characteristic of present-day man, prevent anatomic and physiologic changes that normalize oral pathways. For these reasons, 'textbook' tooth occlusion should be re-evaluated.