A new approach for the diagnosis of b-thalassemia in archaeological contexts: the relationship between congenital anaemia and dentinogenesis defects through micro-CT

The application of radiology as an aid for paleoanthropological analyses is seeing a widespread increase. The aim of this study is to examine a number of radiological dental aspects related to hereditary haemoglobinopathies, such as b-thalassemia, visible on the human remains of a past community by way of micro-CT, in order to support the difficult diagnosis of b-thalassemia in sub-adult individuals documented in archaeological contexts. A sample was selected from the early medieval (tenth–eleventh century) site of Vetricella (Scarlino, Grosseto), located in an area historically affected by malaria. The study was divided in two phases: in phase 1, macroscopic paleopathological analysis revealed features typical of b-thalassemia while CT analysis of the ribs, as demonstrated in previous studies, confirmed the presence of b-thalassemia in the sample. In phase 2, the dental micro-CT carried out on a sample of 7 deciduous incisors belonging to 7 sub-adult individuals allowed to observe for the first time a direct relationship between the degrees of anaemia recorded on the thalassemic skeletons and dentinogenesis defects, identifying also a new radiological evidence which will be termed as “iris-like” appearance. A sample of three individuals from a coeval, non-thalassemic community was used for comparative purposes. These observations constitute a new approach for the diagnosis of b-thalassemia in archaeological contexts, providing an additional tool for differential diagnoses while also furthering our knowledge of the natural history of this disease.