Abstract
In October, 1958, “Tokyo Dental Association” executed the task of the public health dentistry about the people engaged in works and factories in Tokyo. On that occasion, the people who were medically and clinically examined in mass by the members of “Tokyo Dental Association” and perfectly registered the results on 6, 200 sheets of personal oral examination table at 130 works and factories here, all of which were the objects of the our studies. And then, the works and factories of the objects in view were concerned divided and by each industrial phase further subdivided into business servants, laborers and in each work and factory examined. And as for teeth examinations they were divided such as Decayed, Missing, Filled teeth and DMF, as for the gum of teeth such as deposition of dental calculus, gingivitis and pyorrhoea alveolaris, each contraction and the rate contraction were sought for, compared at once, with the relation of each tooth to each gingiva, using the table of correlation as well as the coefficient of correlation between and came to the following conclusion:
1. In comparison of each industrial phase division with one another, the public servants, generally speaking, compared with other industrial laborers showed high tendency in healthy teeth and low in gingiva sufferings and dental hygiene condition seemed to be improving.
2. As for business servants and laborers, the business servants at large compared with laborers showed lower tendency in Decayed and Missing teeth, but higher in Filled ones and lower suffering from gingivitis and pyorrhoea alveolaris and the dental hygiene condition seemed, in general, better.
3. As to the comparison with sexes, men, compared with women, showed higher tendency in pyorrhoea alveolaris in the cases of business servants, but lower in gingiva cases on the part of laborers.
4. As for the correlation between teeth and gingiva, in the total of business servants and laborers, in the total of men and women, that of filled teeth and deposition of dental culculus, showed negative correlation; while on the part of business servants, Decayed teeth and deposition of dental culculus, proved active correlation; we found negative correlation in men laborers, and in women active one respectively, however, especially in the case of DMF, the relation between teeth and gingiva in business servants being active, while negative correlation was shown in laborers.
5. The laborers, generally speaking, compared with business servants show worse condition of dental hygiene, therefore, the plan of promoting dental hygiene in laborers and in women should especially, be taken more care of, hereafter.
