下齒槽神經 切除後 再生에 關한 組織學的 硏究

A HISTOLOGIC STUDY ON THE NERVE REGENERATION AFTER SECTIONING OF THE INFERIOR ALVEOLAR NERVE IN THE RABBITS

The author obserbed the regeneration of the inferior alveolar nerve sectioning of the rabbits histologically. Sixteen rabbits were used in this experiment. The weight of the animals varied from 1.5~2.0kg. As a method, under general anesthesia by means of intravenous injection 1% Pentotal Sodium 25mg/kg. Right mandible were dissected partially on the inferior mandibular border at the anterior border of masseter muscle with the round bur. And inferior alveolar nerves were sectioned to 5mm by surgical scissor. The rabbits were killed at periods of one, three, five, seven weeks. The right jaws were removed, fixed in 10% formalin, Paraffin embedded and stained with Hematoxylin and Eosin, Masson s trichrome, Gomori s for reticulin fiber. The results were as follows. 1. One week-Initiation of new bone formation along the surface of mandibular canal was mainly in the area of injury to the inferior alveolar nerve. There was evidence of myelin degeneration (Wallerian degeneration) phagocytic cells were present in the areas of degeneration in both proximal and the distal segment of the severed nerve. 2. Three weeks-Osteophytic bone and osteoid tissue formation on the surface of mandibular canal. At the distal portion of the proximal segment, there was a decrease in the amount of myelin degeneration but an increase in the activity of Schwann cell. The nerve buds emanating in a wavy pattern from the proximal segment. 3. Seven weeks-The endosteum nad returned to a normal physiologic state. The myelin degeneration at the distal portion at the nerve appeared in less quantity than at the proximal portion.