Histomorphological study on hypocellularity in mastoid processes from archaeological human skeletons

Abstract

ObjectiveTo evaluate processes causing two types of mastoid hypocellularity (Type 1 and Type 3), and to provide histomorphological criteria for a differential diagnosis in archaeological human bone. Materials and methodsEight human crania from the early medieval cemetery in Dirmstein (Rhineland-Palatinate, Germany) displaying secondary obliteration of mastoid air cells were analyzed using light-microscopy and backscattered electron imaging. ResultsIn Type 1 hypocellularity, obliteration starts in the non-pneumatized portion of the mastoid process and extends into the pneumatized portion. The findings could represent a chronic, maybe recurrent condition related to a pathologically altered middle ear mucosa in early childhood. In Type 3, a sequence of resorptive and proliferative processes are present and are consistent with a healing stage of mastoiditis. ConclusionsUsing histomorphology, in vivo processes resulting in different types of mastoid hypocellularity can be assessed, even in bones that have undergone some degree of diagenesis. SignificanceThe study provides methods to evaluate the etiology of histomorphological changes of the mastoid process, which potentially provides insight into the presence of infection and inflammation in past populations. LimitationsDiagenetic modifications of archaeological bone can hinder assessment of histomorphological change, requiring careful evaluation during analysis. Suggestions for further researchIncluding histomorphology in future studies on archaeological human crania can contribute to an improved differential diagnosis of pathological conditions in the middle ear region.