Topographical Landmarks for the Identification of Branches of Mandibular Nerve and Its Surgical Implications: A Cadaveric Study

Introduction Basic knowledge of anatomy is crucial in providing predictable, safe, and efficacious mandibular anesthesia as the mandibular nerve is vulnerable to injury during dental procedures and other surgical manoeuvers. The lack of availability of the appropriate topographical bony landmarks for the location of the branches of this nerve often accounts for iatrogenic injuries and the failure to obtain adequate local anesthaesia. Hence we aimed to describe the topographical landmarks of the branches of the mandibular nerve and their variations in the infratemporal fossa. Methodology In 16 formalin-fixed cadavers, irrespective of the sex of the cadavers, bilateral dissection of the infratemporal fossa was done after identifying the necessary bony landmarks. The mandibular nerve and its branches were traced out and the required measurements were taken using the digital vernier caliper. The results were statistically analysed for mean, range, and standard deviation. Results The masseteric nerve is 15.87+/-1.64 mm superior to the lowest point on the mandibular notch. The lingual nerve in the third molar area is at the depth of 24.75+/-2.38 mm from the angle of the mandible (gonion), making an angle of 50° with the base of the mandible. 20.13+/-3.1 mm inferior to the mandibular notch is the precise location of the mandibular foramen which allows access to the inferior alveolar nerve. The incidence of accessory mandibular foramen in the dissected samples is 9.37%. Conclusion The topography of the masseteric nerve, lingual nerve, and inferior alveolar nerve was studied using constant and reliable bony landmarks in the cadaver which might aid effective dental and facio-maxillary surgical procedures. However, the outcome of this study could not be applied to paediatric patients as the subjects were restricted to adult cadavers.