抄録
Courses and distribution of the nerve fibers in the periodontium has been studied on dogs, cats, rabbits, gunea pigs, mice and albino rats, and the following results has been obtained. 1) The nerve fibers supplying the periodontium came to distribute there from the bottom, wall, and crest of the alveolar bone, all the way beind accompanied by blood vessels. 2) In the periphery, however, this parallelism of nerves and blood vessels became obscure, and there remained only network ramification of the nervc fibers to be seen. 3) Exit of the nerve fibers from the periodontium took place partly through the walls of the alveolar bone toward into the bone marrow, and partly through the periodontium at the cervical region toward the gingiva. 4) Patterns in which the nerve distributed in the periodontium differed among two groups of carnivorous and rodent animals examined, in the following manner : a. In the carnivorous animals, the nerve developed into large plexus at the portion beneath the root apex, though it became rarefied toward upper part of the root. In the rodents, however, the nerve distributed almost uniformly over entire periodontium from the root apex to the cervical region of the teeth. b. In the rodents, the nerve fibers distributed very close to the alveolar bone, while in the carnivorous animals, the nerve fibers were seen relatively abundantly even in the vicinity of the cementum. c. With the rodents' incisors, the pattern of the nerve distribution on their labial and lingual surfaces was quite different one from the other. 5) There failed to be seen any single nerve fiber entering into the cementum. 6) The nerve endings allowed to be discriminated grossly into three forms, branchings, non-branching and glomerate, and in the carnivorous animals, the complicated branching form of nerve ending was more frequently observed than in the rodents examined. 7) In view of the forms in which the nerve endings occurred, it was presumed that the periodontium served mainly to receive tactile sensation, and partly also pain sensation.
