Abstract
Various factors possibly affecting the eruption patterns of the human deciduous teeth were investigated on a total of 855 subjects, 507 males and 348 females, residing in kitakyushu district and ranging in age from 50 to 450 days. The items studied included the body weight at birth, the respective increment of the body weight, body height, chest girth and head girth of the subjects with advancing age, with reference to such factors as the body weight and height of their mothers and maternal age at the delivery. Results obtained are summarized as follows. 1. The percent eruption of deciduous teeth was 21.5% for the males at the age range from 150 to 199 days, and 19.3% for the females at the same age range. This increased with advancing age, reaching 100% at the age range from 400 to 449, without showing any significant sex difference. 2. The average number of erupted deciduous teeth at the age of 150 to 199 days counted 0.5 in the male and 0.1 in the female, and at the age of 400 to 449 days this increased to 9.0 in the male and 9.3 in the female. The male member had more erupted deciduous teeth than the female. 3. The body weight at birth was greater in subjects having erupted deciduous teeth than in those having no erupted teeth with both sexes. 4. The increment in the body height was likewise greater in the former group of subjects than in the latter. 5. The increment of the body weight also showed a similar trend like above. 6. With regard to the increment of the chest girth, there was hardly found any difference between both groups of subjects. 7. The adove situation also held true with the increment of the head girth. 8. No significant correlation was found between patterns of the deciduous teeth eruption of all the subjects and the average values of the body weight and height of their parents. 9. There was hardly found any significant correlation between patterns of the deciduous teeth eruption of all the subjects and the average age of their mothers at the delivery.
