STUDY OF OCCURRENCE OF THE ANTERIOR TUBERCLE IN THE MARGIN OF THE OCCIPITAL FORAMEN IN BIHAR STATE REGION

Abstract

Background: The presence of structures that pass along the anterior margin of the occipital foramen interposed between the basilar part of the occipital and the atlas may reduce the circumference of the foramen causing compression of the spinal cord and leading to signs and symptoms of neurological decits due to its asymmetry. The aim of this study was to determine the incidence of anterior tubercle at the occipital foramen margin. Out of 50 skulls, 2 (4%) skulls shows occurrence of the anterior tubercle in the margin the occipital foramen/foramen magnum with different antero-posterior and transverse measurement . Tubercle was found in the anterior margin of the occipital foramen in 2 (two) skull, The incidence of occipital tubercle, probably formed by the apical ligament exostosis of the dens, was 04 %. In 1st case the tubercle had a triangular shape, was situated at the midpoint of the anterior margin of the foramen, with its apex facing back toward the occipital foramen and measuring about 4mm in the antero-posterior direction and 3 mm in the transverse. In 2nd case a pyramidal projection was found at the anterior margin of foramen magnum, with the apex directed backwards towards the posterior margin of foramen magnum. The tubercle measured 3.5 mm antero-posteriorly and 2mm transversely. The knowledge of the presence of the occipital tubercle is of great clinical importance, as it may lead in many cases to compression of the neurovascular structures.