Anthropometric analysis of the infraorbital foramen in a South Indian population.

INTRODUCTION The aim of this study was to document the morphological and topographical anatomy of the infraorbital foramen (IOF) in relation to the infraorbital rim (IOR), which is necessary in clinical situations that require regional nerve blocks. METHODS A total of 80 dry South Indian adult human skulls of unknown age and gender were studied. In each skull, the IOF on both sides was measured using a metal casing digital vernier caliper, with the IOR as the reference point. The IOF's location and its transverse and vertical diameters were measured. The shape, size, orientation and accessory foramens of the IOF were also documented. RESULTS The majority of IOF among the skulls were oval-shaped on both the right (55 percent) and left (51.25 percent) sides. The majority were directed inferomedially on both the right (55 percent) and left (52.50 percent) sides. The overall combined distance between the IOR and IOF was 4.1 to 11.5 (6.57 +/- 1.28) mm. The overall combined vertical diameter was 1.2 to 4.7 (2.82 +/- 0.79) mm. The overall combined transverse diameter was 1 to 5.1 (2.87 +/- 0.78) mm. Accessory foramens of IOF were found in 13 (16.25 percent) skulls. CONCLUSION Knowledge of the anatomical characteristics of IOF locations, diameters, shapes, directions and its accessory foramens may have important implications on blocking the infraorbital nerve for surgical and local anaesthetic planning. Information on the shape of the foramens obtained from this study may provide additional guidance to surgeons when introducing needles in anaesthetic procedures.