The infirmary where this study has been carried out is visited daily by 200 to 300 children, ranging in age from 2 to 14 years. The great majority of this number are in need of immediate dental care. Only a few are even relatively free from dental caries, and a detailed examination of children over 4 years of age almost invariably discloses the existence of some carious lesions. Frequently such extensive and rapid disintegration of the teeth occurs that neither the regular operative treatment nor oral prophylaxis prevents the continuous progress of the disease. During the last year two groups of children, representing extremes in dental condition, have been studied with respect to their previous history and their present state of health and nutrition.
SELECTION OF SUBJECTS
After a survey of the frequency and character of dental caries in 200 patients, 32 children were selected for intensive study. The selection