A Study on the Incidence and Morphometry of Interparietal Bone in Adult Human Skulls

Abstract

BACKGROUND Interparietal bones are accessory bones in the occipital region of human skull. As independent bones they always lie above the highest nuchal line, separated from the rest of the occipital bone by transverse occipital suture or mendosal suture. Occurrence of this bones are rare compared to the occurrence of sutural bones in this region. The human skull consists of two parts-neurocranium & viscerocranium. The neurocranium consists of eight cranial bones. Of these bones, the occipital bone forms much of the back & base of cranium. It has 4-parts-a squamosal part, a basilar part and 2 condylar parts. (1) We wanted to study the occurrence of interparietal bones in human skull and determine as to whether they are single, bipartite, tripartite or multipartite along with their size and position. METHODS Fifty dried intact adult human skull were examined in this study. The study samples were procured from the Department of Anatomy, Govt. T.D. Medical College, Alappuzha. They were closely inspected for the presence and number of fragments. RESULTS The incidence of interparietal bones was found to be 6%. The interparietal bone frequently occurred singly. Out of 50 skull bones studied, 3 bones showed presence of interparietal bones. Out of three, one was fragmented & other two were single. CONCLUSIONS The result obtained gives information regarding the occurrence of interparietal bones in the human skull and about their number, size, and position. The knowledge of their presence is of great significance to neurosurgeons, radiologists, anthropologists and anatomists.

The Morphometric analysis of accessory sutural bones with an emphasis on association with parietal emissary foramina

“…The accessory bones develop from the separate ossification centers in the interparietal region. The interparietal portion remains separated from the supraoccipital part by a transverse suture, resulting in the occurrence of an Inca bone [9]. The variations in size, shape, number, and position of accessory bones are very common [10].…”