Morphometric nerve fiber analysis and aging process of the human inferior alveolar nerve

We studied morphometric nerve fiber analysis and the aging process of the inferior alveolar nerve (IAN). Human IANs were resected at the mandibular foramen. The preparation of sections involved fixation, washing, dehydration, embedding, sectioning and staining as described in our previous reports. We estimated the total number of myelinated axons in the IAN being average 26,200, the transverse area of those being average 37.1 microns 2, the average perimeter of those being 23.0 microns, the average circularity ratio of those being 0.85, respectively. According to these results, the IAN did not demonstrate notable age-relation change in any measured item. The IAN differed from not only our previous data on the human motor peripheral nerves but also those on the human sensory peripheral nerves. With regard to the aging process, the IAN indicated morphological features compared with other peripheral nerves.