Foramen Magnum: Morphometry, Possible Variation In The Shape And Its Clinical Implication

ABSTRACT

Introduction: Foramen magnum is midline opening in the occipital bone in the floor of posterior cranial fossa. Morphometryof cranium also helps in establishing the origin of various neurological and skeletal pathologies and also designing varioussurgical procedures and approaches.Methods: We conducted a study on 50 dry skull bones in the Department of Anatomy, Government Medical College and Hospital,Chandigarh. The foramen magnum was analyzed for its shape, anteroposterior (AP) diameter, width/transverse diameter (TD),area, perimeter, and FM index. All the measurements were taken with Vernier caliper and were statistically evaluated.Results: The common shape observed was hexagonal in 45% of cases. The mean of AP and TD was found to be 34.44 mmand 30.46 mm. AP diameter was more than TD. FM index and perimeter were found to be 98.91 mm and 88.44. However, areaof foramen magnum was observed to be 745.727 mm2.