A Study of Anterior Superior Alveolar Nerve Variation in Asian and Caucasian Cadavers

The anterior superior alveolar nerve (ASAN) is a branch of the infraorbital nerve (ION) which traverses the anterior wall of the maxilla in a distinct bone canal known as canalis sinuosus (CS). Traumatic or iatrogenic injury to this nerve may result in neurological deficit such as dental or upper lip numbness, tingling sensation or pain over the facial region. The purpose of this study was to look for morphometric variation of ASAN from surgically important landmark, the pyriform aperture (PA) and to look for variation in the branching pattern of ASAN in Asian and compare it to Caucasian cadavers. The study was carried out by identifying the ASAN on anterior wall of maxillary sinus in 60 hemifaces of 15 Asian and 15 Caucasian cadaver heads. We found a significant difference between the two ethnics in horizontal distance from ASAN loop until the lateral border of PA (Mann-Whitney U test; P  = 0.049). There was also statistical difference in the branching pattern of ASAN when analyzed according to ethnicity of cadavers (chi-square test; P  = 0.005). Distances of ASAN from surgically important landmark as well as its branching pattern in Asian and Caucasian can be different. Therefore, the surgeon should be aware to modify the techniques of surgery to reduce the risk of nerve injury in the local setting as appropriate.