Abstract
Since Nordin et al. and Schmid (1955) reported bone grafting in the defects of cleft alveolus and palate, negative views of early bone grafting have arisen because maxillary bone growth inhibition, malocclusion and so on. In secondary cases of the cleft palates of the adolescents, however, good cosmetic and functional results came from bone or periosteal grafting. It has been reported that electrical stimulation to the periosteum was characterized by the existence of the defined bone formation. Transplantation of electrically stimulated periosteum (ESP) was useful as augmentation in bone defects.
In the present study, adult Japanese monkies were used. The tibial periosteum was electrically stimulated by direct current of 20 μA for 2 weeks and the ESP consisting of large ammounts of osteoid with proliferating osteoblasts was transplanted into the artificially defected region of the palatal bone. At the same time, the ESP was transplanted into the muscle tissue of the same animals. As a control, non-electrically stimulated periosteum was transplanted into the palatal bone defect region and the muscle.
The X-ray findings showed that new bone formation was identified in the ESP transplanted area of all cases after 1 and 2 month treatments. In the control side, however bone defect without ESP, showed no bone formation. Histologically, transplanted ESP into the palatal bone defect was differentiated to more calcified, matured bone and not proliferated in situ, excluding bone absorption, and that the ESP transplanted into the muscle has formed a defined bone. The ESP showed that osteogenesis was included Cambium layer in periosteum, proliferated undifferentiated mesenchymal cells, osteoblasts, osteocytes and osteoid. The proliferated undifferentiated mesenchymal cells in the ESP were directly differentiated into osteoblasts and formed bone. As new bone is definitely formed in this method, this is a clinically useful one as a boneless bone graft.
