A probable case of cranial osteopenia in aboriginal societies from northern Argentina

Abstract

Osteopenia is a pathological condition that involves a decrease in bone mineral density and consequently a disproportionate loss of bone mass. Such decrease in bone mineral density is the cause of symmetrical biparietal thinning or resorption in the human skulland its precise etiology is considered to be uncertain. This paper aims to present a case of cranial osteopenia which has caused the presence of biparietal thinning in an adult individual from an archaeological site in northern Argentina dated at the time of contact in the area. Age and sex examination and anthropometrical measurements were performed using standard techniques. Macroscopic evaluation was complemented with X-ray images. The affected skull belongs to a male individual of +50 years. Resorption affects symmetrically both parietals. Thinning in both bones extends from the upper temporal line up to 21 mm of the sagittal suture, covering a depressed surface located between the lateral eminence and the coronal suture. The affected areas form two signifiant concavities, appreciable in the superior and the lateral norms of the cranium. Both depressions on the skull exhibit diameters of 60 and 40 mm. Diploe and the outer and inner tables are of equal thickness. Cranial osteopenia, including bilateral resorption of parietal bones, is not a common fiding in ancient skeletal material. The importance of the present study is to add a particular archaeological case in northern Argentina, and consequently in the southern cone of South America, to the geographic distribution of this rare condition in past populations of the world.