Abstract
We investigated on the status of existing rate of deciduous teeth, eruption rate of permanent teeth, dft rate and DMFT rate in 1967. The subject of study consisted of 145 males, 145 females of the children entering primary school in Kitakyushu city. Results were summarized as follows. 1. Existing Rate of Deciduous Teeth : In the male, the rate was slightly higher than in the female. 2. Existing Rate of Deciduous Teeth : In the Kitakyushu city, the rate was lower than in the Kokura city (1951) and Saga city (1959). 3. Eruption Rate of Permanent Teeth : In the female, the rate was higher than in the male. 4. Eruption Rate of Permanent Teeth : In the Kitakyushu city, the rate was higher than in the Kokura city (1951). 5. dft Rate : In the female, the rate was slightly higher than in the male. 6. dft Rate : In the Kitakyushu city, the rate was higher than in the Kokura city (1951). 7. DMFT Rate of the first molars : In the maxillary teeth, the rate was no sex difference between the two subjects, but in the submaxillary teeth of the female, the rate was slightly higher than the male. 8. Difference between the Kitakyushu city and Kokura city (1951) in the DMFT Rate of the first molars : In the male, it was nearly equal both two cities, but in the female, the rate of Kitakyushu city was higher than the Kokura city (1951).
