An Experimental Study on the Change of the Nerve Distribution in the Free Mucosal Transplantation

Abstract

Free skin transplantation and free mucosal transplantation were conducted clinically and histologically by many investigators. But many of these reports are about the observation of healing process generally after transplantation and the articles on the chronological changes of the nerve fibers in the mucosal grafts and the recipient beds, as far as the author has read, could hardly be found. So, the author conducted free mucosal transplantation experimentally by using the mucosal part of the lip of dog and examined its healing process patho-histologically and nerve-histologically. Results were summarized as follows ; 1. Around the 20th day after transplantation, slight contraction in the mucosal grafts was observed. After that not many changes in contraction could be observed. 2. In dogs which have melanin pigment at the recipient beds, the composure of melanin pigment into the margin of mucosal grafts could be observed around the 60th day after transplantation. 3. After transplantation, the epitheliums of mucosal grafts degenerated gradually and fell off, but a part of them survived in stripped condition. On the 5th day after transplantation, on the other hand, the epithelium of peripheral insized tissue and the epithelium surviving in stripped condition increased and began to cover the mucosal grafts, and on the 10th day it was covered completely. 4. In regenerated epithelial layer the rete pegs of each size were observed at first. Around the 20th day after transplantation, however, it became thin and flat. And from the 60th day the formation of short rete pegs was observed. 5. For one or two days after transplantation, the mucosal grafts were attached to the recipient beds with fibrin net and clot. On the 3rd day after transplantation, these junctions were observed and on the 7th day, they became complete. 6. Connective tissue under the epitheliums of mucosal grafts caused edema and alienation in the early stage after transplantation, but on the 20th day it became minute fibrous connective tissue and gradually became rough and around the 120th day it became resemble normal tissue. 7. New blood vessels of the mucosal grafts appeared on the 5th day after transplantation and they increased gradually and they became large, too. On the 30th day they became indistinguishable from that normal tissue. 8. Nerve fibers in the mucosal grafts suffered from, what is called, the Wallers degeneration and on the 7th to 10th day after transplantation they almost vanished. 9. The degenerated process of the nerve fibers differs according to their size. On the first day after transplantation, the nerve fibers of large and middle size were already degenerating, but those of small size showed the normal finding, but on second day the nerve fibers of small size also began to degenerate and after that there was little difference between the degeneration of each nerve fiber. 10. After transplantation, nerve fibers of the mucosal grafts disappeared gradually and Schwann cell increased and began to show the restis arrangement and it could be observed in all parts of the mucosal grafts. 11. On the 5th day after transplantation, observed finding of nerve fibers was seen at the cut end and the lateral of the nerve fibers at the junction of the mucosal grafts with the recipient beds. On the 10th day after transplantation, they came to enter the mucosal grafts. On the 15th day, they could be observed in every part of mucosal grafts 12. In the regenerated nerve fibers, some are closely connected with Schwann cell band and some have nothing to do with it. Most of the former were found in ones which form the bundles, and most of the latter were found in individual ones. From about 20th day after transplantation, ones that have no connection with Schwann cell band were decreasing gradually. 13. Around the 30th day after transplantation, the formation of nerve endings was observed in the regenerated nerve

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