Analysis of morphology of foramen magnum in Indian population

The foramen magnum is a unique and complex neuroanatomical structure. This is an important landmark of the skull base for neurosurgical procedures. The aim of this study is to analyze the morphometry pertaining to variations of the shapes and sizes of foramen magnum separately for males and females of Indian population along with comparing antero-posterior and transverse diameters available in literature and to bring out associated clinical implications. Thirty-five dry skulls (13 females and 22 males) have been examined for morphometric variations of foramen magnum. The surface area of foramen magnum was calculated manually using graphical method. The importance of morphometry and clinical significance of foramen magnum has been established by available literature. Mean antero-posterior diameter and transverse diameter of foramen magnum are 33.8 ± 02.5 mm and 28.2 ± 02.6 mm, respectively. The minimum, maximum and mean areas of foramen magnum in assorted skulls are 434 mm2, 902 mm2 and 648.5 ± 112.2 mm2, respectively. Foramen magnum index in assorted skulls vary from 1 to 1.45. The dimensions of foramen magnum, separately for males and females in the Indian population, have been analyzed for the first time. This analysis will be of paramount importance for clinicians in surgical procedures around this region.