论文标题:颧骨牵张成骨修复部分上颌骨缺失的实验研究
The Experimental Study for the Segmental Reconstruction of Maxilla Loss by Distraction Osteogenesis of Zygoma
论文作者 牛学刚
论文导师 赵铱民,论文学位 博士,论文专业 口腔临床医学
论文单位 第四军医大学,点击次数 63,论文页数 102页File Size10375k
2005-04-01论文网 http://www.lw23.com/lunwen_513181227/ 牵张成骨;上颌骨;颧骨;牵张器;功能性修复
distraction osteogenesis; maxilla; zygoma; distractor; functional reconstruction
上颌骨缺失是严重的颌面部缺损之一,由于上颌骨特殊的解剖形态和组织结构,缺损区难以利用自体组织重建,多以上颌赝复体进行修复。然而,当单侧上颌骨缺失,患侧牙齿和牙槽骨组织大部或全部丧失时,义颌主要依靠健侧组织提供固位和支持,在缺损侧则缺乏有效的支持,受力时存在下沉、翻转趋势,长期的杠杆作用对健侧的牙齿、种植体不利,双侧上颌骨缺失时,义颌固位和承力不良,咀嚼功能受损的状况更加严重。因此,上颌骨缺失行赝复治疗时,如何使赝复体在双侧均获得有效支持是急需解决的问题。骨结合式种植体在颧骨区的应用为解决此难题提供了途径,以种植体为固位,承力基础的赝复体能够在很大程度上实现咀嚼功能重建,但此种方法还有待进一步优化,因为颧骨位置较高,种植体植入点深入到缺损腔内部,不利于其清洁、卫生,而且,种植体长轴与咬合力方向不一致,长期承受侧向力对种植体骨界面不利。而若能充分利用近年来迅速发展的颅颌面牵张成骨技术则可望在不植骨的情况下,将缺损侧颧骨由高位牵引至低位,替代缺失的部分上颌骨,成为缺损侧的骨性支持结构,并可在其中植入位置和方向适宜的种植体,从而为咀嚼功能重建奠定良好基础。 目前,已有学者采用牵张成骨术将颧骨颧弓拉长、拉宽,以矫正颌骨畸形,
The maxilla is the functional and aesthetic keystone of the midface. The patients suffer a lot from its loss. But maxillary reconstruction has posed a significant challenge because of the complex anatomy and neighborship . Nowadays , the maxillary prostheses are still the main modality for the reconstruction of the maxilla before the development of more sophisticated techniques .However ,how to achieve enough retention and support is the biggest problem in the reconstruction . In the condition of unilateral maxilla loss, only the ? residual tissue of healthy side is available for limited retention and support. The prostheses are liable to sink and turnover with the result of nerghboring tissue damaged .When bilateral maxilla lost ,the situation would be more worse. To overcome it, the clinicians apply the osseointegrated implant technique to the zygoma region .The employment of implants in the zygoma region provides good basis for the retention and support of maxillary prostheses . Nevertheless, because of zygoma" high position, the implants are always deep into the defect cavity with the disadvantage of difficulty of cleaning ,and prostheses are inconvenient to be takenand removed .Even Worse,the implants could only be put into the zygoma inclinedly ,the axis of it could not be unanimous to the occlusal force. So the occlusal force would act on the implants laterally, the peri-implant bone might be injured because of long term lateral force. However, if the technique of craniofacial distraction osteogenesis could be used to stretch the remained zygoma forward and downward to reconstruct the part of lost maxilla, the bony support could be set up ,and also, the implants could be applied in more suitable direction .On this basis, the mastication function reconstruction might be achieved better.The area of connection of zygoma and maxilla takes on a curved structure. So ,to reconstruct maxilla as possible,the zygoma should be distracted around an arc.The key of the success is the distractor.However ,most distractors used today are straight type, only straight distraction osteogenesis could be completed by them. Although ,some kinds of arced distractors have been invented and used ,they are usually external types and serve for DO of mandible.No one is suitable to zygoma. So,a new kind of internal arced distractor which could be applied to zygoma was designed and manufactured by ourself .The device was tested through animal experimental research and the vitro imitation on the dry human skull specimen.The research comprised of four part. Part I, The experimental animal model of DO of zygoma for the segmental reconstruction of maxilla loss was established to decide the way of DO of zygoma and test the feasibility of it; Part II, The animal experimental study of internal straight DO of zygoma for the segmental reconstruction of maxilla loss was performed. In the process of DO and after the specimen taken, the distracted areas were evaluated by general observation radiography histologic study SEM and BMD analysis to test and verify the feasibility and regularity of the DO of zygoma, and to investigate the effect of
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