Topography and Spatial Fascicular Arrangement of the Human Inferior Alveolar Nerve

Background: Topography and fascicular arrangement of the inferior alveolar nerve (IAN) can provide critical information for the estimation of damage to IAN based on patient symptoms, or conversely to evaluate the symptoms resulting from injury to the IAN. Purpose: The fascicular composition and organization of the IAN were determined to confirm the microarchitecture of the IAN bundles into each of the mandibular teeth, including the composition of the mental nerve. Materials and Methods: The IAN within the mandibular canal (MC) was examined in 30 hemifaces of embalmed Korean cadavers. Results: The most common patterns of nerve fascicle innervation to the mandibular teeth could be grossly classified into three: (1) the superior buccal portion of the IAN innervating the molars, (2) the superior portion innervating the premolars, and (3) the superior lingual or the superior lingual and inferior lingual portions in the posterior MC and the lingual portions in the anterior MC, innervating the incisors and canine. The buccal two-thirds portion of the IAN was composed of the mental nerve. Conclusion: The IAN had distinctive fascicular organizations, which make it possible to forecast the degree, location, and extent of nerve damage according to presenting symptoms.