99mTc-MDP를 이용한 하악골의 자가골 이식의 평가에 대한 실험적 연구

An Experimental Study on the Evaluation of Mandibular Autogenous Bone Graft with 99mTc-MDP Bone Scan

The early and exact evaluation of the healing state of bone graft is very important and essential in practice. Author undertook the objective method for evaluating the bone graft healing in this study. This study was designed to compare three diagnostic methods at 1, 2, 4, 6, 8, week intervals after autogenous bone grafting in the dog s mandible: the conventional radiography, the histologic examination, and the analyzed data derived from the bone scanning with 99mTc-MDP. The obtained results were as follows. 1. The static image and the tomography of the bone scan demonstrated greater radioactivity in the experimental grafts than in the control during the whole experimental period, and the analyses on the tomography were more sensitive and accurate than on the static image because of avoiding of overlaying with other neighbouring anatomic structures. 2. The radioactivity ratios between the counts for pixel in the bone graft area and the counts for pixel in the control area showed increasing figures at one week, reached peaks at two weeks, then decreased and became stable between 4 and 8 weeks, but remained rather higher than normal state. 3. On the histologic findings, the recipients and the grafts were united with fibrous connective tissue and new bone formed predominantly at one and two weeks, on four weeks and after the recipients and the grafts were united with newly formed trabecular bone. There was a localized necrosis at the bone marrow of the grafts, however the grafts exhibited a plenty of vascularity and viability during the whole experimental period. 4. Since the radioactivity ratios seemed to be correlating to the degree of the bone graft healing in the comparison of conventional radiography and histologic findings as the immature bone were being replaced by mature bone, the bone scan was considered to be a useful objective method for evalvating the bone graft healing.