Prevalence of Accessory Infraorbital Foramen in South India: An Anatomical Study

Cross sectional observational study was carried out to estimate the prevalence of accessory infraorbital foramen on both sides in a collection of 200 skulls available in the Department of Anatomy, St John’s Medical College, and other medical colleges of Bangalore. India. The data of the present study will be of considerably use to cliniciansanaesthetist following failure of infiltration of anaesthetic agent and an operating surgeon for preventing injury to the nerves. †Assistant Professor ‡Professor †Corresponding author INTRODUCTION Infraorbital foramen (IOF) is located on the anterior surface of the maxilla of norma frontalis. The infraorbital nerves and vessels exit through this foramen. Infraorbital nerve is the continuation of the maxillary nerve, which provides sensory supply to lower eyelid, lateral part of the nose, upper lip through its orbital, nasal and labial branches (Snell, 2008) . The foramen is usually single occasionally additional foramen ranging from two to four has been reported as accessory foramen. The reported prevalence of accessory foramen is 2.2 to 18.2% (Bery, ’75; Canan, ’99; Aziz, 2000; Higashizawa, 2001; Kazkayasi, 2001; Kyung, 2007) and is not applicable to all population, is variable between ethnic groups. Sound knowledge of anatomic, ethnic variability, is essential for various surgical, anesthetic and growing cosmetic facial procedures. Infraorbital nerve block is one of the commonly preferred blocks for operative procedures of the face, as it can be easily approached either by transcutaneous or transoral routes. On considering the clinical importance and variability the present study was undertaken to estimate the prevalence of accessory infraorbital foramen in South Indian skulls. MATERIAL AND METHODS Cross sectional observational study was carried out on two hundred skulls (four hundred sides, 200 right and 200 left sides) from the collection of department of Anatomy, St John’s medical college, Bangalore. There is no record of age or sex of these skulls. They are all presumed to be of mixed South Indian origin. Norma frontalis was inspected for the presence of accessory infraorbital foramen on the anterior surface of the maxilla. When present patency, number, shape, diameter (measured using digital calliper) and relation to main infraorbital foramen confirmed by observation. The damaged and broken skulls were excluded from the study. The results were analysed and expressed as percentage.