Reinterpreting Cribra Orbitalia Etiology in a Coastal North Carolina Algonkian Population using Computed Tomography

Abstract

Cribra orbitalia is visually characterized by porous lesions on the orbital roof and is often attributed to iron deficiency anemia, although other etiologies are possible. The main objective of this study is to reassess the diagnosis of iron-deficiency related cribra orbitalia in a North Carolina coastal Algonkian population (n= 50, AD 295-1460) using non-destructive methods. Microscopic techniques such as thin-ground sectioning have successfully differentiated between diploic expansion attributed to anemia as opposed pathological expressions related to other etiologies. However, such destructive techniques often are not possible with some U.S. samples because of NAGPRA provisions. Thus, we utilize non-invasive computed tomography (CT) scanning an alternative to identifying diploic expansion versus other causes of porosity in the orbital roof. Out of a total sample size of 183 crania, 45 crania with varied forms of upper orbital lesions and 5 crania without such lesions were selected for CT scanning analysis. The axial anterior-posterior CT images would allow for distinction between diploic expansion and resorption of the corresponding cortical bone and cortical bone porosity. This preliminary study suggests that although in most cases CT scanning observations are the same as simple visual analysis, in some instances CT scanning allows for a more accurate diagnosis of diploic expansion versus porosity. While cribra orbitalia is usually attributed to anemia, orbital lesions can also indicate dietary deficiencies within the population. By more accurately understanding the etiology of cribra orbitalia in archaeological populations, we can better understand their dietary habits, health, quality of life, and overall adaptations to their unique environment. Reconsidering the etiology of cribra orbitalia has important implications for the current interpretations of malnutrition and infectious disease in earlier human populations. This new non-destructive methodology has implications for paleopathological methodology, archaeology, and Native American history.