Analysis of Bone Variations of the Occipital Bone in Man

Abstract

Inadequate ossification of the interparietal region induces the appearance of interparietal and wormian bones, also associated with genetic factors. The formation of the interparietal bone depends on the separation of the intermediate segment from the lateral plate by the transverse occipital suture, which means that this bone is formed by the medial and lateral plates. Wormian interparietal bones or epactal bones are located within the interparietal region, being single or multiple, and are located in the upper central region of the interparietal region, the sutural bones, however, are formed from additional ossification centers that can occur in near sutures. The aim of this work was to macroscopically evaluated the presence of changes in the structure of the adult human occipital bone in cadavers found in the human anatomy laboratory of the Gois Federal University in order to determine the frequency of supernumerary bones associated with occipital and parietal bones and relate it to literature, as well as to provide images and data for ethnic studies in the Brazilian population and data that could help medical practices such as fetal position and radiographs. Our data have indicated that the frequency of the interparietal bone of 1.92% is among those seen in countries such as Japan, Bulgaria, Nigeria, India and Turkey, but lower than values found in pre-Hispanics Chileans; however, for the sutural bones, the frequency of this study was higher than other data obtained from Spanish and other Brazilians.