Age estimation from stages of epiphyseal union in the presacral vertebrae

The presacral vertebrae have various secondary centers of ossification, whose timing of fusion can be used for age estimation of human skeletal remains up to the middle to the latter third decade. However, detailed information about the age at which these secondary centers of ossification fuse has been lacking. In this study, the timing of epiphyseal union in presacral vertebrae was studied in a sample of modern Portuguese skeletons (57 females and 47 males) between the ages of 9 and 30, taken from the Lisbon documented skeletal collection. A detailed photographic record of these epiphyses and the age ranges for the different stages of epiphyseal union are provided. Partial union of epiphyses was observed from 11 to 27 years of age. In general, centers of ossification begin to fuse first in the cervical and lumbar vertebrae, followed by centers of ossification in the thoracic region. The first center of ossification to complete fusion is usually that of the mammillary process in lumbar vertebrae. This is usually followed by that of the transverse process, spinous transverse process, and annular ring, regardless of vertebra type. There were no statistically significant sex differences in timing of fusion, but there was a trend toward early maturation in females for some vertebra or epiphyses. Bilateral epiphyses did not show statistically significant differences in timing of fusion. This study offers information on timing of fusion of diverse epiphyseal locations useful for age estimation of complete or fragmented human skeletal remains.