These experiments were based on human clinical autologous transplantation of the lower third molar into the space of an extracted first molar and homologous transplantation of human teeth. These operations have been repeated by many clinicians 1-5 and radiographic and clinical evidence have been submitted as criteria for success. This type of clinical research left many questions unanswered. Further work was started, 6-8 using the rhesus monkey as the experimental animal.The rhesus monkey was selected because its physiology and anatomy are similar to those of the human being and because it is not a laboratory inbred strain. The clinical procedure was duplicated in every respect, except that the rhesus monkey was substituted for the human subject.Because of the anatomical characteristics of the rhesus monkey, the lower third molar has not proved to be a good tooth for transplanting. It is too large to readily fit into the region of the jaw to which it would be transferred. Reports on this work are inconclusive because of the variable factors encountered.9 The experiment was repeated, except that transfers between right and left mandibular incisors were made, other conditions being the same.
Materials and MethodsForty autologous operations were performed, involving lower permanent central incisors. The right incisor was removed and the socket was prepared for the left lower incisor. The left lower incisor was then removed and its socket prepared for the lower right incisor. After the immediate transfer of the teeth was made, the gingival tissues were sutured from labial to lingual aspects across the contacts. No other method was used to stabilize the transplants.Twenty monkeys of either sex were used, the development of the teeth to be transplanted being the guiding factor for the selection of the monkeys. Radiographs were used to determine root growth. In previous autologous operations, general experience has indicated that the stage of development of the donor tooth should include approximately a third of the root formation. Consequently, the donor tooth is not a tooth germ and is not a tooth bud; rather, it is a fully developed and calcified crown with a partially developed root.During the operation, a tooth was extracted from its own socket and, for the short time it took to prepare the recipient socket, it was kept in a gauze sponge moistened with physiologic saline solution. Antibiotics were not used after the operation. Periodic radiographs were made for longterm studies and, in most instances, were made 6 months after transplantations.At postoperative intervals of 4, 8, 21, and 31 days and 3, 7, 9, and 11 months, the monkeys were sacrificed and tissue preparations were made for observation. Monkeys were anesthetized with pentobarbital sodium* injected into the saphenous vein and sacrificed by perfusion, under positive pressure in the ascending aorta, with an isotonic saline solution until clear fluid was observed flowing from an outlet opening that was made into the heart and then with a 10 percent neutral ...