Kieser et al. (Kieser J, Kieser D, Hauman T. The course and distribution of the inferior alveolar nerve in the edentulous mandible. J Craniofac Surg. 2005 Jan;16(1):6-9. ) investigated the vertical positioning and intrabony branching patterns of the IAN in 39 edentulous human cadaveric mandibles by buccal microdissection. Dissected mandibles were classified on the basis of the height of the IAN within the body of the mandible and the branching pattern of the IAN. The IAN was located in the superior part of the body of the mandible in 30.7% (12/39) of cases, all of which showed a small posterior molar plexus of branches. In 69.2% (27/39), the IAN was half-way or closer to the inferior border of the mandible. All of these latter cases, 41% demonstrated a small, posterior molar plexus of branches, 37% showed posterior and anterior plexuses, and 22% had either no branches or a single trunk with a small number of single branches directed at the superior border of the mandible.
This is an exerpt from Anatomy of Mandibular Vital Structures. Part I: Mandibular Canal and Inferior Alveolar Neurovascular Bundle in Relation with Dental Implantology (Juodzbalys et al. J Oral Maxillofac Res 2010).