论文标题:牵张成骨技术修复兔下颌骨创伤性缺损的实验研究
Study on Reconstruction of Rabbits" Mandibular Traumatic Defects by DO Technique
论文作者 刘瑞峰
论文导师 周树夏,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 146,论文页数 107页File Size12794k
2005-04-01论文网 http://www.lw23.com/lunwen_38387082/ 下颌骨;内置式牵张器;牵张成骨;延迟期;牵张期;牵张速度;牵张频率;固定期;骨膜;骨内膜;下齿槽血管束;血供;骨密度;生物力学;三点弯曲强度;抗弯强度;X射线能谱分析扫描电镜;骨钙磷含量;骨面积比;碱性成纤维细胞生长因子;微血管密度
mandible; internal distracter; distraction osteogenesis; latency period; distraction period; distraction rate; distraction frequency; consolidation period; periosteum; endosteum; inferior alveolar vessels; blood supply; bone mineral density; biomechanics; 3-point bending strength; bending strength; x-ray energy analysis; scanning electronic microscope; bone calcium phosphorus ratio; bone area ratio; basic fibroblast growth factor; micro vessels density
颌面部是人体的暴露部分,无论平时或战时都容易遭受创伤。而下颌骨创伤后常常导致骨部分缺损,修复方法较多,主要包括骨移植和生物替代材料移植等,其中自体髂骨、肋骨、腓骨移植开展最广泛。国内外学者为了研究颌面部创伤的致伤机理以及损伤范围,相继建立了瑞典模型、颌面部高速投射物模型、颌面部爆炸伤模型以及颌面部爆冲复合伤模型等,研究不同致伤方式下颌面部骨组织及软组织的损伤程度以及损伤范围,确定了清创范围;并检测了损伤组织内与创伤及组织修复有关的细胞因子的表达及其作用,认为颌面部火器伤可进行一期修复,并且成功地进行了动物实验以及临床应用。 牵张成骨(DO)技术是一种通过外科手术在骨切开术或骨皮质切开术后植入具有牵引延长功能的固定装置,通过外力在截骨线的两端牵张使骨组织之间形成新骨的技术。该技术是利用骨组织的自身愈合能力来增加新骨的一种方法。牵张成骨的实验研究及临床应用表明,该技术之所以能增加骨量是因为骨组织具有自身愈合能力,而牵张区的外骨膜、内骨膜以及血供起着重要作用。但下颌骨的创伤性缺损,尤其是火器伤或爆炸伤引起的缺损,骨断端周围的骨膜、骨质以及周围软组织的血供受到不同程度的损害,此状态下
Maxillofacial regions are often under attack whether in war times or peace times, and mandibular trauma often results in partial bone defect. There are a lot of methods to rehabilitate mandibular defects, including bone graft and biomaterial substitues, in which autogenous bones such as ilia, ribs and fibulae are the most frequently used ones. Scholars from craniomaxillofacial departments around the world have established many traumatic animal models to study the mechanism of injury in maxillofacial region, such as Sweden Model, high speed projectile injury model, blast injury model and blast-explosive injury model in maxillofacial regions. They have studied the severity and range of bone tissue and soft tissue injury from different kinds of trauma, and determined the range of debridement, and surveyed the expression and function of various kinds of cytokines within the traumatic tissues. They concluded that mandibular defects resulting from firearm injuries could be rehabilitated in early stage, and many experiments and clinical experiences confirmed the hypothesis.Distraction Ostogenesis technique is a new method to generate newbones between bone fragments by distration devices after osteotomy. Experimental studies and clinical applications show that the mechanism of regenerate bone by DO is attributed to the ability of concrescence of bones. The periosteum and endosteum and blood supply of the distraction area and the nearby areas are the most important factors during DO procesure. The traumatic defects of mandible, especially suffered from firearm or explosive injuries, are lack of blood supply and loss of periosteum, so could we rehabilitate the defects in this situation? Could we precede the regenerate bone formation by delivery some kinds of angiogenic growth factors? Bone formation is closely linked to blood vessel invasion. Therefore, neo-formation of blood vessels in bone could enhance bone formation. Neo-formation of blood vessels in a tissue can achieve by exogenous delivery. Bone formation is preceded by vascular invasion and osteogenesis takes place in the vicinity of newly formed vessels, that mediate delivery of osteoprogenitor cells, secrete mitogens for osteoblasts, and transport nutrients and oxygen. In this experiment we simulated madibular traumatic defects to investigate the feasibility of mandibular reconstruction in this situation, loss of periosteum and lack of blood supply, and we investigate the feasibility of angiogenic growth factor delivery to precede bone formation in this situation. Four parts are included in this study. As follows:Part 1 Experimental Model of DO in the Rabbits" Mandible and theDistraction ParametersTo determine the parameters of prolonging of the rabbits" mandibles by DO after severe trauma, we simulate unilateral mandible trauma and prolong it by DO. In this study we use adultrabbits (provided by Experimental Animal Department of Fourth Military Medical University), weighing from 2.4 to 2.6kg. For every rabbit we apply mandibular osteotomy, and then introduce internal distraction devices by which both of the rabbits" mandibles can be prolonged. We destroyed the blood supply of the left mandible by removing the periosteum and cut the inferior alveolar vessels to simulate mandibular trauma. Latency period is 1 or 7 days, and distraction rate is 0.5 or 1.0mm per day, distraction length is 10 mm and consolidation period is 4 weeks. After 4 weeks the regenerate bones with 7 days latency period are better than those with 1 day latency period. DO technique can be used even after the blood supply of the mandibles are destroyed, but the latency period should be lengthened, and this may have some implications to the clinics in rehabilitation of mandible defects in early stage after trauma.Part 2 Effects of Local Appliction of rbFGF on rabbits" mandiblularprolonging by DOIn this part we simulate bilateral mandible trauma and prolong the bilateral mandible of rabbit by DO, and the distraction parameters: 7 days latency period, l.Omm/d distraction rate, 2/d, distraction length 10
|
