CONCERNING DEFECTS IN THE ENAMEL OF TEETH OF ANCIENT AMERICAN INDIANS

¹ Laboratory of Oral Histology and Embryology, Columbia University Dental School, New York City

The conclusions to be drawn from the examination of the teeth of some of the older tribes of America are these:

1. Enamel fissures or defects in the protective covering of the teeth were present to as great a degree as they are in the teeth of individuals of today.

2. Enamel defects did not, at that time, predispose these teeth to decay, as shown by the fact that the incidence of dental caries was exceedingly low.

3. The force of mastication of gritty food must have been considerable, judging from the degree of abrasion, and far beyond anything seen today in the teeth of civilized man. The intensity of this abrasion is not only shown on the occlusal surfaces, but also in the approximal areas (fig. 6). The individual movement of the teeth (which is again doubted by one investigator) has abraded the approximal surfaces to such a degree that, in certain places, the entire enamel has been worn off, exposing the underlying dentine. In spite of the exposure of this more vulnerable tissue between the teeth, no decay resulted. This is an added proof of the presence of a mysterious immunity to dental caries, which to my mind will be found in the health of the individual.

4. Even though enamel fissures did not apparently dispose the teeth of the ancient Indians to decay, this thought must certainly not be applied to the teeth of civilized man. Here they are an active predisposing factor, on account of the highly refined, pappy, acid-forming food of today, and the lower degree of vitality of the body, resulting in an impaired resistance of the dental tissues to decay.

5. Enamel fissures must therefore be treated early in order to maintain the teeth of civilized man in a more healthy condition.