HE published literature indicates little concern about information on the 1 distribution of various attacks further than counts of the average number of teeth or surfaces per mouth affected by caries; and there is already evidence to suggest that neither of these measures may have more than limited value.From the studies which have been made of the distribution of the caries attack on teeth by specific types, locations, or surfaces, only a very incomplete picture may be glimpsed. It is surprising, in the face of the tremendous effort that has been made to learn the nature of the various process through the past 60 years, that this aspect of the problem has apparently not attracted closer attention.All the earlier studies of the kind indicated have been characterized by various limitations, though collectively they may be viewed as offering a valuable nucleus of information. Arnim3 analyzed data from several independent surveys into a kind of rating, by tooth surfaces affected; limited in their value, however, by the absence of radiographic findings for proximal attacks, and by an arbitrary grouping of attack frequencies into 5 categories. One of the present authors5 has presented more detailed data on proximal attacks, but it was limited to median age levels of from 7.5 to 22.5 years, and did not report the pit or fissure or the cervical attacks. More recently, Dirks, Winkler, and Van Aken14 and Galagan and Vermillion,17 intending primarily to study the radiographic technic for examination of proximal surfaces, have presented data confined to proximal surfaces of posterior teeth in adolescents. These studies, even collectively, offer neither a sufficiently comprehensive range nor are they on a properly comparable basis so as to permit the compilation of figures to indicate the pattern of incidence of caries by location or type for each tooth of the dentition.
DESIGN OF STUDYOpportunity was taken to add to a comprehensive program, planned for study of the epidemiology of periodontal disease, sufficient additional examinations to provide data on the distribution of various attacks on the teeth. The