根尖病巣の神経病理学的研究

Abstract

A total of 72 chronic inflammatory human periapical lesions were investigated for the distribution of nerve fibers, using improved Powers' impregnation method. The lesions were 7 cases of slight chronic apical periodontitis, 6 cases of chronic apical purulent periodontitis, 47 cases of radicular granuloma (simple-33 cases, epitheliated-12 cases) and 12 cases of radicular cyst. The results were as follows : 1. A large nerve bundle accompanying blood vessels entered the chronic inflammatory periapical lesions through the vasoneural space at the bottom of alveolar fossa. The distribution of nerve fibers in the lesions were divided into two groups. One group of the nerve fibers penetrated straight into the inner zone through the outer zone of the lesions, the others ran parallel with the connective tissue that formed the outer zone, and ramified extensively. 2. Few nerve fibers were observed in the epithelium of the lesions, but in some cases a few nerve fibers were found in it. 3. The nerve fibers distributed in the lesions were composed of both myelinated and unmyelinated fibers. In the inner zone the numbers of unmyelinated fibers were much more than those of myelinated fibers. 4. The nerve fibers penetrating into the lesions were mainly composed of sensory nerves and a few vegetable nerve fibers accompanying blood vessels. 5. Most of all sensory nerve fibers in the lesions showed free nerve endings. 6. On the distribution of nerve fibers there was a distinct difference among the same type of the lesions. This seems to have relation to the kind of tooth, case history and the degree of inflammation. 7. In chronic inflammatory lesions, large myelinated nerve fibers sometimes showed slight degenerative changes but most of the fibers were morphologically intact.