Innervation of the Hamster Maxillary Incisor

¹ Department of Histology, College of Dentistry, University of Illinois, Chicago, Illinois

This study was based on 12 hamsters ranging in postnatal age from 13 days to 26 months. The extradental investigation consisted of gross dissections and tracings of anterior superior alveolar nerve and of microscopic examination of thick serial sections. The study of pulpal innervation of hamster incisors consisted of serial histologic sections at 10 and 15 µ.

The following findings were observed: There is a recurrent branch of the superior alveolar nerve that courses posteriorly from in front of the nasolacrimal duct to the basal end of the incisor and sends bundles into the tooth. Three distinct areas of the pulpal innervation were characterized by different neural morphology, corresponding to the metabolic activity of the pulpal tissues. The basal third of the incisor showed growing nerve fibers, the middle third mature myelinated fibers, and the incisal third degenerating nerve fibers.