An experimental study of the effect of the orthodontic tooth movement into the bone graft area of the cleft palate patient

本研究旨在评价自体PMCB(颗粒骨髓和松质骨)和TCPC(β-磷酸三钙陶瓷)移植到实验性诱导性颌骨缺损修复过程中的组织学变化，并比较它们对正畸力的反应。实验结果如下：1)在植骨后1~2周，PMCB表面出现早期的吸收和坏死；另一方面，在植骨后8周左右，PMCB表面出现直接的对位成骨；8周左右，PMCB和同种异体颗粒被新骨形成重塑；同种异体充填区重建的骨结构比植骨区更接近于牙槽骨；2)在植骨后5周内，施加正畸力的PMCB区有牙根吸收和坏死颗粒残留。3)施加正畸力的合植区生物降解和新骨形成增加，这可能是正畸力作用的结果。4)在两个部位均观察到牙骨质和牙周膜的再生。因此，在骨重建的早期，PMCB似乎不能对正畸力做出适当的反应，而合体移植物对正畸力的反应比PMCB更合适。提示TCPC是一种更好的骨形成支架，在正畸力承重区，临床上非常有用的材料作为自体骨的更好的替代材料。

This study was performed to evaluate the histological changes during remodelling of autogenous PMCB(particulate marrow and cancellous bone) and TCPC(beta-tricalcium phosphate ceramic) when trans planted into the experimentary induced jaw bony defects and compared their responses to the orthod ontic force. Following results were obtained.1)Early resorption and necrosis was observed on the surface of PMCB before appositional bone formation occurred about 1-2 weeks following bone graft.On the other hand,directly appositional bone formation was observed on the surface of the Synthograft granules.lost of PMCB and Synthograft granules were remodelled by new bone formation around 8 weeks following the graft procedure.The reconstructed bony architecture of Synthograft filled area was more similar to that of the alveolar bone than the bone graft area.2)In the PMCB area root resorption and remnants of necrosed graft particles were observed where orthodontic force was applied within 5 weeks following the bone graft. However,a good biological responses to the orthodontic force were observed in the both areas after 7 weeks.3)Increased biodegradation and new bone formation were found in the Synthograft area where orthodontic force was applied.It may be the result of the applied orthodontic force.4)The regeneration of cementum and periodontal ligament was observed in the both areas.Thus,it is concluded that,PMCB seemed to be not able to response appropriately to the orthodontic force in the early bone remodelling stage,while Synthograft showed more appropriate response to the orthodontic force than PMCB.IT is suggested that TCPC is a better scaffold for bone formation where orthodontic force bearing area,and clinically very useful material as a better alternative substitute for autogenous bone.