Abstract: The purpose of this paper is to discuss the nature of compact bone age-associated changes, so as to provide the evidence of age estimation with bones for forensic medical and anthropological research.
The middle one third of right sixth rib was collected from 86 Chinese males of north China, ranging from 20 to 70 years of age. Decalcified cross-section slides were histomorphometrically examined by using an image analyzer. Histological parameters used in this study included 10 items :total intact osteon area (X1), intact osteon number (X2), average intact osteon area (X3), total Haversian canal area (X4), average Haversian canal area (X5), total fragmentary osteon area (X6), fragmentary osteon number (X7), average fragmentary osteon area (X8), total visible osteocyte number (X9), and total visible osteon density (X10). The results showed that intact osteon number, total Haversian canal area, average Haversian canal area, fragmentary osteon number, total visible osteon density increased with age, the correlation coefficients were 0.896, 0.835, 0.491, 0.748 and 0.906 respectively; and average intact osteon area, average fragmentary osteon area, total visible osteocyte number decreased with age, the correlation coefficients were -0.750, -0.767 and -0.715 respectively; but total intact osteon area and total fragmentary osteon area didn' t change with age significantly (r=-0.005, 0.011). Then the 10 parameters were subjected to multiple stepwise regression analysis to produce an equation: Y =33.545 +0.938X2 +249.144X4 +0.676X7 -769.784X8 -0.004X9, its multiple correlation coefficient and standard error of estimate were 0.954 and 4.14, respectively. When the formula was tested on 30 specimens, 77% of the estimated ages fall within ±5 years of actual ages, and 100% of the estimated ages fall within ±8 years of actual ages. This paper provides a new method of age determination by bone for forensic medicine and anthropology.

Key words: Forensic anthropology; Skeleton age; Rib; Histomorphometry