Microscopic age changes in the human occipital bone

The value of histological examination of the human occipital bone for estimation of age-at-death was assessed. Undecalcified sections of occipital bone from eighteen male Caucasian subjects between the ages of 21 and 70 years were prepared for analysis using polarized light microscopy. The fractional volumes of primary osteons, secondary osteons, osteon fragments, and lamellar bone in both the outer and inner cortical tables were determined. It was found that with increasing age there is a decrease in the fractional volume of primary osteons and a significant decrease in the fractional volume of lamellar bone. The fractional volume of secondary osteons was not found to change significantly with age, while the fractional volume of osteon fragments significantly increases. The microscopic results reflect the continuous process of bone remodeling that is responsible for the variation in cortical parameters with age and is the primary basis for age predicting methods. While observable changes in the occipital bone do occur with increasing age, the amount of random variation in the parameters examined preclude their use for accurate age estimation.