The teeth are related to the skeleton and their growth and permanence are governed probably by somewhat similar laws of nutrition as are the bones. It is certain that in rickets the child fails to develop sound teeth having dense and faultless enamel, and that the roots of the teeth do not develop as they should. There has been very serious deterioration of the teeth of civilized people in many parts of the world during the last century, especially in parts of England and North America and the British overseas dominions. This has been variously attributed to the eating of cooked food, soft food, failure to properly clean the teeth, etc. Mouth hygiene has recently enjoyed great popularity, and the slogan "a clean tooth never decays" is frequently seen, especially in the advertisements for tooth pastes and tooth brushes. While commendable as a general hygienic measure, mouth hygiene doubtless has little, if anything, to do with the preservation of the teeth. All measures hitherto proposed, which stress cleanliness and prompt repair, do not get at the root of the evil. The development during very early life of a sound set of teeth is the most important factor in preventive dentistry. This is not so much dependent on the softness or hardness of the food, in infancy and very early childhood, as it is on the composition of the diet. If this is not adjusted in an entirely satisfactory manner, the bones and teeth will be poorly developed, and decay of the teeth in early life is then unavoidable. Chewing hard foods is, however, an important measure for insuring the development of the tissues immediately surrounding the roots, and for developing the jaws.

348. Primitive Man Had Neither Rickets Nor Decayed Teeth

In the National Museum at Washington there are several hundreds of skulls of Indians who lived between two hundred and three hundred years ago. They are from the Aleutian Islands down the Pacific coast through Honduras and Yucatan, into Peru and across to the South Sea Islands. Only a single tooth showed dental caries in the entire collection. Among these primitive peoples the diet was excellent from the standpoint of chemical completeness, and bone defects and bad teeth were unknown or nearly so. The introduction of large amounts of cereals and of tubers into the diet by civilized and urban populations has resulted during the last century in rapid falling off in physical stamina and increase in skeletal defects.

349. Prevalence Of Decayed Teeth Among American Children

Butler (26) points out that an examination of 7,059 children in West Virginia revealed 16,151 cavities exclusive of those containing fillings. Under-developed jaws and irregular teeth were surprisingly prevalent. 5,935 children examined showed these defects in 1,759 cases. There is nothing in our national life which is more pressing for attention or more important from the standpoint of public health than attention to this matter. The only effective way to attack the problem is through the diet of the expectant mother and of the infant and young child. This must be constituted better than is now the case.