Abstract
The purpose of the study was to investigate differences in the occlusal force, height, body weight and maximum mouth opening range between Japanese and Chinese children with different social environment and foods. Subjects participating in the study included 546 Japanese children from Gifu prefecture and 237 Chinese children from Shanghai city aged 7,9,11 and 12 years old. The results obtained were as follows
1. The occlusal force of Japanese boys were significantly stronger than that of Japanese girls in every age group and that of Chinese boys significantly stronger than that of Chinese girls in the 11 and 12year old group. The occlusal force of Chinese girls was significantly stronger than that of Japanese girls in every age group.
2. The physical development (height, body weight) of Chinese children was significantly higher in value than that of Japanese children in both genders.
3. The mouth opening range of Japanese boys was significantly wider than that of Japanese girls in the 11 and 12 year old group and that of Chinese girls was significantly wider than that of Chinese boys in the 7 year age group. Furthermore, that of Japanese boys was significantly wider than that of Chinese boys in the 7,11 and 12 year old group, and Japanese girls was significantly wider than Chinese girls in the 11 and 12 year old group.
4. Though the occlusal force showed a positive correlation with the age in the children or both countries, no significant correlation between the occlusal force and physical development (height, body weight) in each age group was found.
These findings suggest that the increase of occlusal force may be influenced by the circumstances in which the children have grown up.
