Variations in origin, course and distribution of lingual nerve: A cadaveric study

Abstract

Introduction: The lingual nerve is a branch from posterior trunk of mandibular nerve and is sensory to the tongue, lingual gingivae and conveys postganglionic secretomotor fibres to submandibular, sublingual and anterior lingual glands. The nerve is joined by the chorda tympani branch of the facial nerve, and often by a branch of the inferior alveolar nerve. Submandibular ganglion is connected to the lingual by anterior and posterior filaments.1 Communications between Lingual nerve (LN) and Mylohyoid nerve (MHN) may be the possible explanation for the functional recovery of LN when its get injured during third molar extraction.4 Materials and Methods: A study was carried out in twenty embalmed cadavers and forty lingual nerves were studied by standard dissection method. Results: out of forty lingual nerves studied one lingual nerve was found to be arising from two roots. Anterior (AR) & posterior (PR). Mylohyoid nerve was found to be connected with the submandibular ganglion by two roots (anterior and posterior) and later was found to join the lingual nerve. A CB from LN joined posterior root. Discussion: Kim et al. described the communication between MHN & LN in 12.5% of 32 heads and first mentioned that this communication could provide another route of sensory transmission, being a possible cause of incomplete anaesthesia during dental practice.6 Conclusion: Our study showed multiple variations in one specimen which included variation in its origin (partly taking origin from anterior division of MN along with posterior division), communication with MHN, MHN was connected to submandibular ganglion by two roots. The incidences of all these variations in our study were 2.5%. Keywords: Lingual nerve, Inferior alveolar nerve, Mylohyoid nerve, Submandibular ganglion.