Animal Experimental Study Of Repairing Cranial Defects With Autogenous Skull Bone Dust

Objective The aim of the study was to investigate basical problems of repairing cranial defects with autogenous skull bone dust by establishing animal model for directing to clinical work better.Methods Thirty new zealand white rabbits were selected with sex unlimited. Three whole thick defects(A B C) were created in the parietal bone of every new zealand white rabbit. Defect A was left empty as control. Defect B was grafted with autogenous skull bone dust with two pieces pyroxylin membrane placed on two side like a hamburger. Defect C was grafted with autogenous skull bone dust only. After 4,8,12 weeks 10 rabbits were killed and the defects were prepared for general observation,X-ray inspection,3-dimension CT rebuilding,histological analysis and calcium content mensuration.Results There was great amount of connective tissue entering the defect A with a little new bone formed .Defect B was repaired with new spongy bone in the early period,but maturation of the new bone formed was slow. Defect C was repaired with more mature new bone formed, but it in the centre of defect C was too thin. The autogenous skull bone dust was absorbed gradually. There were a lot of vessels in the zone of new bone formed. The new bone formed in the defect C was more mature than in the defect B in the same period (P<0.05). the calcium content of the new bone formed after operation 12 weeks is higher than that of after operation 4and 8 weeks(P<0.05). The fashion of repairing defect B was different from defect C. Conclusions A close temporal and spatial relationship exists between formation of regenerated bone and vascular proliferation. The use of pyroxylin membrane significantly promote the autogenous skull bone dust transfering into primary spongy bone.