STUDIES ON THE INDUSTRIAL DENTAL HYGIENE (III)

Abstract

During the Labor Health Week observed in October 1957, the Tokyo Dental Association planned out and performed a dental health service for workers of factories and other places of enterprises with the cooperation of those organization concerned as part of its social dental health program.The authors classfied the oral examination tables, 15, 104 sheets in all then drawn up by the same Association, according to those wards and the suburban area to which said factories and other places of enterprises belonged.(Note: The suburban are as termed here means cities and other administrative districts of Tokyo Metropolis exclusive of the wards.)And then, in respect of thus classified tables, the authors made observations of dental statistical values of DMF, missing teeth (not including dummy and denture), filled teeth (including dummy and denture), general dental caries (which was classified again in three categories of surface caries, deep-seated caries and root stump caries), respectively, in two sections of caries incidence percentages and average numbers of teeth per person.Note: Average numbers of teeth per person of termed here means average numbers of DMF, missing teeth, filled teeth, general dental caries, surface caries, deep-seated caries and root stump caries, respectively, per person.The results are:1. In each of the two sections of caries incidence percentages and average numbers of teeth per person, surface caries has a highly significant or a significant positive correlation with the density of population of each ward and the suburban area, but other items of dental statistical values have no correlation.2. In the section of caries incidence percentages, root stump caries has a significant negative correlation with the dental statistical values of each ward and the suburban area, but other items have no correlation.3. As regards the relations between any one item of dental statistical values and the density of dentist population of each ward and the suburban area, in the section of caries incidence percentages, DMF, filled teeth and root stump caries, and in the section of average numbers of teeth per persons, filled teeth and general dental caries, respectively have a significant, positive correlation with the density of dentist population of each ward and the suburban area, but items have no correlation.4. The relation of DMF of each ward and the suburban area to missing teeth, general dental caries, surface caries, deep-seated caries and root stump caries was calculated by use of correlation coefficients, and it was found that in both the sections of caries incidence percentages and average numbers of teeth per person, the DMF has a highly significant or a significant, positive correlation with filled teeth, general dental caries, deep-seated caries and root stump caries, but no correlation with other items.Various kinds of dental statistical values of each ward and the suburban area as observed from the angle of regional enviroment show that the relation of surface caries to the population and the number of dentists of each ward and the suburban area is peculiar and that dental caries must be discovered early and treated early.Again, both in caries incidence percentages and average numbers of teeth per person, the effect of filled teeth on DMF as viewed from the regional standpoint is the greatest, and next comes the effect of deep-seated caries and general dental caries.