DIET IN RELATION TO THE TEETH

The importance which the so-called focal infections have lately assumed as sources of disease has brought new prominence to the relation of the teeth to such infections. Indeed, pyorrhea alveolaris has tended to overshadow the far more widespread defects of carious teeth in which the conspicuous damage penetrates rather than surrounds these structures. If further evidence of the almost universal incidence of dental caries were needed, the records of the systematic examination of pupils in the public schools would testify to the degree of prevalence of teeth defects. The underlying causes are still unknown. They have usually been sought in local bacteriologic conditions within the mouth, if one may conclude from the emphasis that dentists place on oral hygiene. They seem not to realize that the presence of bacteria in itself never causes disease: we have millions of bacteria in our intestine and still thrive. What harm do the micro-organisms