Morphology and topography of the parietal emissary foramina in South Indians: an anatomical study.

The objectives of the present study were to study the prevalence of the parietal emissary vein in adult South Indian population and to study the distance of foramen from the sagittal suture. There were 58 adult human skulls in the present study which were available at the anatomy department of our institution. The study included 116 parietal bones which have been observed macroscopically for the number, prevalence and topography of the emissary foramen. The emissary foramen was present in 83 parietal bones (71.5%) of the present study. It was present at the junction between the middle 1/3 and posterior 1/3 region of the parietal bone. The foramen was observed solitary in 73 parietal bones (62.9%), double in 8 bones (6.9%), and triple in 2 parietal bones (1.7%). The foramen was not observed in 33 parietal bones (28.4%). The bilateral absence of parietal emissary foramen was seen in 7 skulls (12.1%). It was absent unilaterally in 19 skulls (32.7%). The accessory foramina were seen in only 8 skulls (13.8%). The mean distance of the foramen from the sagittal suture was 6.7±2.9 mm and 6.8±2.8 mm on the right and left sides respectively. The prevalence of parietal emissary vein in the present study was 71.5%. The present study has observed important data about the morphology and morphometry of the parietal emissary vein in South Indian population. The identification of parietal emissary veins and accessory veins is important in the operation room to prevent the blood loss.