INTERCOSTAL VARIATION AT THE STERNAL END OF THE RIB

The human rib has proven to be an important site for the assessment of age at death in the adult skeleton. The rib phase method, featuring r ace and sex specific standards developed by two of the authors (Iscan and Loth), is proving successful in paleodemography and forensic anthr opology. However, as the authors pointed out in earlier publications, it is not always possible to isolate the fourth rib upon which the sta ndards are based. This can be a factor because although a certain degr ee of intercostal variation does exist, its extent has not been quanti fied in a modern forensic population. Therefore the purpose of this pa per is to determine if standards from the fourth rib can be used for a djacent ribs 3 and 5. Ribs 3, 4, and 5 were collected at autopsy from recent medical examiner's cases of known age, sex and race. The sample consists of 135 white males and females of age range 3-99 years. Each rib was assigned to an age phase using the established standards. The results of this analysis indicated that >79% of cases, all three ribs fell into the same phase, and intercostal differences were within one phase for 98% of the sample. It may thus be concluded that age can al so be assessed from these adjacent ribs using the present standards.