가토 하악골 우각부의 골절단술후 골치유에 관한 실험적 연구

Experimental study on the bone healing, after osteotomy in the mandibular angle of rabbits

The healing in osseous tissue different from soft tissue healing is the regeneration process which doesn t remain scar tissue. For primary bone healing, the ideal method is no gap and rigid fixation. But if the fragments could not fixed without gap, tight bone graft must be recommanded. However, actually in clinic, small gaps during fixation could be occurred, then many surgeons were willing to fix the fragments commonly without bone graft in small gaps because they did not want to make other wound. So, this experiment was performed to know the effect of various sized gap on the bone healing when the fragments were fixed with various sized gaps, and no bone grafts. After submandibular incision and angle exposure, the bony gaps of 0㎜, 1㎜, 3㎜, 5㎜, and 7㎜ were made in each 4 rabbits, and the fragments were fixed rigidly. After 20 weeks, the rabbits were sacrificed and their mandibles were extirpated. The observations and the measurements of the bony defects were performed, and the microscopic specimens were obtained. The results as follows 1. In group of no gap the wounds of bones were healed completely, and in group of 1㎜ the wound were also healed satisfactorily. In these groups, the bony continuities were kept, the new bones in the cut areas were irregular and had high cellularity. 2. In group of 3㎜ the sizes of remaining defects were similar as one of original defects. 3. In group of 5㎜, 7㎜ the defects were partly larger than original defects since bony resorption. From this experiment, author concluded that during reduction and fixation the fragments must be adhere closely without gap. If impossible, the gaps must be minimized.