壓接이 骨癒合過程에 미치는 影響에 關한 硏究

A study to the effect of compression on the bony union process : Histopathologic and photoelastic study

The purpose of this study was to investigate the effect of compression on the bony healing process. Ten Korean dogs weighting about 8-12 ㎏ were selected in order to carry out this experiment. Under the general anesthesia with Ketalar？？, the both side of mandibular angle region were transected from the retromolar triangle superiorly to the antegonial notch inferiorly, care being taken not to compound the fracture into the oral cavity and not to damage the inferior alveolar nerve and vessels. In the right side of osteotomy site were fixed with autocompression plate and screws and in the left side, fixation was performed with stainless steel wire in 0.56 ㎜ diameter. Experimental dogs were sacrificed at 1, 2, 4, 6, and 8 weeks after the surgery and the soft tissue were dissected from the mandible. Thc operation sites were examined under the light microscope to observe the bony repair process histopathologically. To investigate the stress distribution patterns, similar fixation methods were performed on the photoelastic epoxy resin and photoelastic stress analysis was done with the polariscope. The results obtained from this study were as follows; 1. In the wire fixed group, the active bone formation was proceeded from the endosteum and periosteum and large quantity of callus was formed. 2. In the compression plate-fixed group, a large quantity of lamellated bone was matured and than resulted in bony union. Small amount of the callus was also observed. 3. The bony union process of the compression plate fixed group was occurred more rapid than those of the wire fixed group at the early stage, but similar repair processes were observed on both groups at the 6th and 8th weeks after the surgery. 4. In the photoelastic stress analysis, note the tremendous number of pressure lines in the compression plate fixed model than the wire fixed model. And it could be observed that the continuous pressure was applied to the transected area. 5. When the vertical load was applied on the split model, the compression plate fixed model showed the stability without any change of the compression stress or any widening of lower part of model.