FACTORS AFFECTING THE RATE AND PATTERN OF THE FIRST COSTAL CARTILAGE OSSIFICATION

In the present study, the extent of costochondral ossification of the first rib was determined from 78 chest roentgenograms of 13 healthy ma le soldiers subjected to a periodic follow-up. Roentgenography was per formed at a mean interval of 2.9 years over a 15-year period. Mean sub ject age was 24 years at the commencement of the study and 37 years at its termination. Our results show that ossification of the first cost al cartilage may start early in adult life and progress at individual rates. The ossification process proceeded from the costal toward the s ternal end of the cartilage in an anteromedial direction. The morpholo gical age-related changes ranged from the formation of small osseous i slands in the cartilage to a complete ossification between the first r ib and the sternum. The main conclusion of the study is that the degre e of ossification of the first costal cartilage as an indicator of age does not provide the precision necessary for anthropological or foren sic studies.