Periodontal sensory innervation of the dentition of the Japanese shrew mole.

The neurohistological investigation of the periodontal sensory innervation in the whole dentition of the Japanese shrew mole showed that the periodontium is much more densely supplied by the free nerve endings at the apical region than at the intermediate one at a ratio of about 8:1 in the upper dentition and 5:1 in the lower dentition. The interdental gingival tissue is innervated by the nerve plexus formed by the nerve fibers deriving mostly from the gingival and a few periodontal nerve fibers. The neurohistology of the tooth is analogous to that of the vibrissa.