IV. skeletal development from birth to 7 years.

The skeletal development of 212 randomly selected Swedish urban children has been investigated as part of a prospective longitudinal study of growth and development. Radiograms of the hand and wrist were taken at specified ages. Up to the age of seven years 2.191 radiograms were assessed. When comparing the timing of the first ossification of the various bones in the present study and an older Swedish investigation a secular trend was found. In contrast to a North-American growth study, there was a striking similarity of the pattern of the first ossification in the two Swedish investigations for both sexes separately. However, the relative sex differences of the ossification were quite similar in the North-American growth study and the present investigation. In comparison with British children the skeletal development of Swedish children was advanced at all ages, the advancement being greater for epiphyseal bones than for carpal bones.