Frequencies of cribra orbitalia in central Italy (19th century) under special consideration of their degrees of expression.

According to several hematological and anthropological studies the formation of hyperostosis spongiosa orbitae can be attributed to different types of anemias. Since especially in Central Italy the different forms of thalassemia as well as Plasmodium vivax, Plasmodium malariae and Plasmodium falciparum have been rather vastly distributed a study of this trait (differentiating between degrees of expression) on a population sample (125 males, 80 females) including adult, mature and senile skulls has been carried out (anatomical series of the medical faculty of the University of Siena ). However, the high incidence of this trait, though rather weakly expressed (male 56.8%, female 70.0%), and clearly classifiable in three degrees of expression also indicates the existence of other factors involved. Among these factors the nutritional ones could be excluded because this region was scarcely populated and rich in nutritional resources. On the other hand, the low content of Fe and Cl anions in the water could be made up with the assumption of foods abounding for these elements.