Morphometric Study on Wormian Bone of Dry Adult Skull of Nepalese Population.

Background Accessory (supernumerary bone) is small irregular worm like bone. These bones are also known as wormian bone. Accessory bone develops when additional ossification centers appear and form extra bones. Many bones develop from several ossification centers of ossification and these separate parts normally fuse. Sometimes one of these centers fails to fuse with main bone. Circumscribed areas of bone are seen along the sutures of the cranium where flat bones about, particularly related to parietal bone. Objective To investigate presence and to determine morphologic and morphometric characteristics of wormian (sutural) bones. Method The study was conducted on 25 dry human skulls with unknown gender, ethnicity and race in Department of Anatomy, School of Basic Sciences, Kailashnagar, Bharatpur-5, Chitwan Nepal. The study was conducted on 25 dry human skulls with unknown gender, ethnicity and race in Department of Anatomy, School of Basic Sciences, Kailashnagar, Bharatpur-5, Chitwan Nepal. The deformed skull and skull of pediatrics age group are excluded. The location, shape, number and side of Wormian bone are determined. The SPSS 20 program and descriptive statistical method analysis were used for data analysis. Result Total 25 adult dry skulls were observed in the study. Both sides of skull were observed. Out of 25 skulls Wormian bones are not found in left sided three lambdoidal suture (four percent). Conclusion The knowledge of Wormian bones plays a major role for the neurosurgeons, neuroanatomists, radiologists, forensic experts and anthropologist. Presence of few bones are normal. But multiple Wormian bones need attention as it may have underlying skeletal or central nervous system pathology. In radiographs they mimic fracture lines. Wormian bone at pterion may produce complications in neurosurgical procedures like burr holes.