Microscopic and chemical examinations for estimating the time since death of skeletal remains--its application to...

Postmortem changes in human compact bones were examined by microradiography and electron microscopy, simultaneously with an examination of UV-fluorescence in the cross-section of bones by microscopic spectrophotometry. Total protein content in bones were also examined. No significant morphological changes were found in compact bones exposed to the open air for less than 10 years since death. In bones buried in the soil, vacuolation of bone tissues generally began around 5 years since death. This histological changes extended into the mid zone of the substantia compacta in bones of 6 years or more. In bones left in the sea for 4 or 5 years, vacuoles with 5-10 microns in diameter were observed in the outer peripheral zone of the substantia compacta. The relative intensity of UV-fluorescence in the peripheral zone of the substantia compacta dwindled with time since death and their correlation coefficient was considerably high. Although the correlation coefficient of protein content with time since death of bones was significant, it was too low for forensic science application. These microscopic methods were applied to the estimation of bone date in 5 actual criminal cases and the reliability of the determination of time since death based on the present data were evaluated. The results obtained provided good estimations of the bone date.