INCIDENCE OF INTERPARIETAL (INCA) BONES IN THE POPULATION OF ASSAM

Abstract

Rubi Saikia, Bijoy Kumar Borah, Jyotirmayee Lahon, Natasha Gohain

The occipital bone forms the region of the back of the head. It consists of three parts- the squamous part, the basilar part and the two condylar parts on either side of the foramen magnum. The squamous part of the occipital bone consists of two parts – the upper interparietal and the lower supraoccipital part. Usually the interparietal part fuses with the supraoccipital part but sometimes it may remain separated by a suture. Then it is called interparietal bone or Inca bone. AIM & OBJECTIVES: The aim of the present study is to find out the incidence of interparietal or Inca bones in this part of north east India as data regarding its incidence rate and number of fragments of Inca bones from Assam is still underreported. MATERIALS & METHOD: In the present study, a total of 126 dry adult skulls were examined to know the incidence of Inca bones. All the specimens were procured from various departments in Assam Medical College, Dibrugarh, Assam. They were first examined for presence or absence of Inca bones and then for number of fragments. RESULTS & OBSERVATIONS: The incidence of Inca bone was found to be 1.58%. One skull presented with a single triangular Inca bone while another skull presented with two fragments of Inca bones. CONCLUSIONS: The knowledge regarding interparietal bones and that it may present with many fragments is certainly very useful for neurosurgeons, radiologists and anthropologists

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