[A cross-sectional study of the relationship between the ossification of the distal phalanx of the first digit and cranio-facial growth and development].

Abstract

For correction as well as prevention of malocclusion, information about the bone maturity is very important in treatment planning. In this study, ossification of the distal phalanx of the first digit was used as an indicator of bone maturity. We found significant correlation between this ossification of the phalanx and the cranio-facial development. Stage E2 was reached, on the average, at the age of 6 years 4 months in girls and 8 years 11 months in boys, stage E4 at 12 years 9 months in girls and 14 years 11 months in boys. Girls were ahead of boys, the difference being about two years at both E2 and E4 stages. The degree of the cranio-facial development at stage E2 compared with adults was 83.5% in girls and 83.8% in boys; at stage 4 it was 94.8% in girls and 94.5% in boys. At stages E2 and E4, the cranial base was the most developed, the maxilla was next, and then the mandible. This tendency was found in both boys and girls. A4-Go was the least developed at both E2 and E4 stages. The cranio-facial development in the posterior vertical dimension continued to occur for a long period.