1959 Volume 9 Issue 2 Pages 83-90
The Department of Hygiene Kyushu Dental College The average numbers of existed deciduous teeth, permanent teeth eruption and average ages for permanent teeth eruption was investigated and population of school children and pupils in Hagi city consisting of 1186 males and 1200 females from 6 to 15 years old. Comparison was made with the data obtained respectively from groups of 2071 males and 1947 females from 6 to 15 years old and living in Tokuyama city as examined in 1956 by Shindo, and also from groups of 989 males and 909 females, 6 to 14 years old and living in Saga city as examined in 1958 by Shigyo.
The results were summarized as follows.
1. The average numbers of existing deciduous teeth
Hagi city: Male>Female
Male. Female:
Tokuyama city>Hagi city≈Saga city
2. The average numbers of erupted permanent teeth
Hagi city: Male<Female
Male:
Tokuyama city≈Hagi city≈Saga city
Female:
Tokuyama city<Hagi city≈Saga city
3. The average ages for permanent teeth eruption was expressed as follows.
Hagi city: Male>Female
Male:
Tokuyama city>Hagi city≈Saga city
Female:
Tokuyama city≈Hagi city≈Saga city