MS-1型内置式下颌骨骨牵引延长器及其动物实验

目的：报告自行研究开发的内置式下颌骨骨牵引延长器,探讨其用于动物实验的可行性。方法：１５只犬采用ＭＳ－１型下颌骨牵引延长器,并进行单、双侧下颌骨体部牵引延长２０ｍｍ,并进行Ｘ线与组织学观察。结果：实验犬下颌骨牵引延长效果肯定,器械均未见断裂或松动变形,牵引区成骨明显。结论：ＭＳ－１型内置式牵引器具有临床应用可能性。     

下颌骨牵引成骨对颞下颌关节的影响

利用牵引成骨技术扩张延长发育不良的下颌骨已获成功,近年来十分盛行。本文综述下颌骨牵引成骨过程对颞下颌关节影响的动物实验和临床应用研究,特别是下颌骨牵引成骨术对下颌骨发育不良病例的髁状突的影响,阐述应用传递牵引技术对重建髁状突切除术的髁状突和颞下颌关节的作用。     

rhBMP-2对兔下颌骨牵引成骨区骨保护素表达的影响

目的：通过动物实验,研究应用外源性rhBMP-2对兔下颌骨牵引成骨区骨保护素（osteoprotegerin,OPG）的影响。方法：在48只成年大耳白兔的一侧下颌骨前部行骨切开术,分别将空白胶原、rhBMP-2 1.5mg胶原复合物植入下颌骨切开处,用牵引器延长一侧下颌骨4mm,稳定期第1、3、7、14天,分别处死各组动物,取牵引区新生骨痂行组织学及OPG免疫组化染色。结果：下颌牵引延长后牵引间隙均有新骨形成,应用rhBMP-2 1.5mg效果好。免疫组化染色OPG主要定位于成骨细胞的胞浆中。在同一时间内,应用rhBMP-2组较对照组有显著性差异（P〈0.05）。结论：动物实验表明,rhBMP-2能促进兔下颌骨牵引成骨区新骨的生成。     

牵引成骨对牙胚生长发育影响的初步观察

目的:通过对3例下颌骨截骨牵引延长过程的观察,研究牵引成骨对牙胚生长发育及萌出的影响。方法:共有8例小下颌畸形患者接受了下颌骨截开牵引延长治疗以矫治小下颌畸形。其中3例患儿的下颌截骨线上有尚未萌出的牙胚。3例中6侧下颌骨最大牵引延长幅度为22.5mm,最小幅度14mm。在截骨前后、牵引前后及随访过程中X线纵向随访观察,研究牙胚的位置改变及其生长发育的变化过程。结果:经过7～12个月的随访,发现所有在截骨线上或附近的尚未萌出牙胚,在截骨间隙牵开扩大后牙胚将移至牵引间隙中,而且能正常地生长发育、萌出。新骨的沉积钙化速度及新骨成熟所需时间与其他病例无明显差异。结论:手术应避免损伤截骨线上及邻近的尚未萌出的牙胚;在颌骨截开牵引延长的过程中,牵引成骨将不影响牙胚的生长发育,牙胚可以在经牵引形成的新骨中正常地生长发育及萌出;截骨间隙中牙胚的存在不影响新骨的形成。     

下颌骨弹力牵引成骨再生骨密度及强度测量

目的：初步了解下颌骨持续弹力牵引成骨再生骨密度及强度的变化过程,为弹力牵引成骨这一新技术提供基本数据参考。方法：制作bi-focal技术牵引成骨重建一侧下颌骨3．5～4cm节段缺失的杂种犬动物模型,采用6cm长内置正弦波形记忆合金弹力牵引器自动完成牵引成骨,分别利用双能X线骨密度仪和生物力学检测仪测量术后不同时期牵引再生骨段的骨密度及强度。结果：各实验犬牵引再生骨段长度均达到3．0cm以上,术后3个月再生骨中央生长区强度和密度达同侧正常骨段的15％左右,术后4个月时可接近正常骨的40％,术后5个月时可达正常骨密度的60％左右。结论：以较快速度弹力牵引获得的再生骨,后期的骨化成熟过程也较为满意。     

下颌骨牵引成骨过程及机理的实验研究

目的　观察猴下颌骨牵引成骨的动态过程 ,探讨其成骨方式及机理。方法　恒河猴 10只行单侧下颌骨牵引 ,间歇期 5天 ,牵引速度 0 .5mm× 2次 /日 ,共 15天。于牵引后不同时期拍摄X线片 ,行四环素荧光双标记 ,将牵引区骨块标本平分 ,上部骨块制作不脱钙树脂切片 ,5u切片行甲苯胺蓝染色 ,2 0u切片荧光显微镜下测骨组织沉积率 ;下部骨块制作脱钙石蜡切片 ,HE染色。结果　牵引后早期 ,牵引区以平行于牵引方向排列的胶原纤维为主 ,可见纤细骨小梁及大量骨吸收陷窝 ,X线片上表现为低密度透光区。稳定期新骨逐渐由两端向中间形成 ,牵引后 4周 ,牵引中心充满平行排列的骨小梁 ,新骨密度仍低于正常 ;牵引后 6～ 12周 ,牵引区粗大的骨小梁呈网状排列 ,可见成熟哈佛氏系统 ,新骨表面形成骨皮质 ,X线片表现接近正常。牵引完成时骨组织沉积率为对照组的4.2倍 ,在稳定期逐渐减慢 ,但牵引后 12周时仍较对照高 40 .91%。结论　缓慢有规律地牵引下颌骨可明显促进新骨形成速度 ,延长骨段。牵引后足够时间的稳定期是新骨生成的必要条件。牵引区主要以膜内成骨方式形成新骨 ,成骨过程为新生与改建并存。     

内置式牵引成骨技术治疗颌骨畸形

目的 :探讨内置式牵引成骨技术在不同类型的牙颌面畸形治疗中的应用。方法 :应用 2种类型的内置式牵引装置 ,为严重的小颌畸形、上颌后缩畸形、半侧颜面萎缩畸形和下颌骨缺损畸形患者行下颌骨体水平方向延长、上颌骨水平前徙、下颌升支与上颌骨同期垂直向延长以及下颌骨体部双端式牵引延长 ,共 5例。结果 :5例牵引成骨手术 ,部分病例辅助正颌外科手术 ,均达到术前设计要求 ,临床效果满意。 2例因牵引方向导致的错牙合问题 ,在牵引结束时及时得以纠正。无伤口裂开、感染、骨坏死、骨不连等并发症。结论 :应用内置式牵引成骨技术可重建面部轮廓 ,恢复理想的咬合关系和口颌功能 ,创伤小 ,安全可靠     

个体化内置式牵引器在修复下颌骨部分缺损中的应用

目的：应用个体化设计的内置式下颌骨牵引器,通过牵引成骨技术修复下颌骨部分缺损。方法：对因肿瘤行下颌骨部分切除的2例患者,术前根据头颅三维模型,设计个体化内置式牵引器,同期（1例）行肿瘤切除与牵引成骨手术,或二期1例行牵引成骨手术,运用转移盘牵引方式修复下颌骨部分缺损,固定期8～9个月,行X线及CT检查。结果：2例患者均成功进行了牵引器植入手术,术后牵引顺利,其中（1例）出现伤口感染,给予抗生素后得到控制,未影响牵引成骨治疗的进行。2例患者新骨形成均良好,转移盘远端骨质连接间隙处在拆除牵引器时需以植骨或钛板固定。结论：个体化设计的内置式下颌骨牵引器,可以根据不同患者颌骨缺损情况,进行一次性复杂牵引成骨,修复下颌骨部分缺损。     

下颌骨牵引成骨对颞下颌关节的影响

利用牵引成骨技术扩张延长发育不良的下颌骨已获成功,近年来十分盛行。本文综述下颌骨牵引成骨过程对颞下颌关节影响的动物实验和临床应用研究,特别是下颌骨牵引成骨术对下颌骨发育不良病例的髁状突的影响,阐述应用传递牵引技术对重建髁状突切除术的髁状突和颞下颌关节的作用。     

下颌骨牵引成骨与直接延长术的组织学比较

目的：通过对下颌骨牵引成骨与直接延长术组织学变化的对比研究分析，探讨牵引成骨的成骨机制。方法：24只狗随机分为牵引成骨组和直接延长组各12只，用HE染色光镜组织学检查方法分别观察牵引第6天、牵引后固定2、8周不同时期的两组组织学变化。结果：牵引组在牵引后固定第8周，牵引区几乎完全由新生的骨组织连接修复，成骨方式是以膜内成骨为主，伴有少量的软骨内成骨；而直接延长组仅早期在两骨断端附近可见活跃的膜内成骨，两周以后则以软骨内成骨为丰，中间区域仍为大量的纤维结缔组织，8周以后成骨量增加．但中央仍为软骨组织和纤维组织间隔。结论：牵引成骨以膜内成骨为主，达到良好的骨愈合，直接延长成骨效果不稳定，容易导致成骨不良。     

Distraction osteogenesis for reconstruction after mandibular segmental resection.

Distraction osteogenesis with the shortening and lengthening method is a well-established procedure for repairing extremities. We used this technique for reconstruction after mandibular segmental resection. A 74-year-old woman underwent distraction osteogenesis with an intraoral device, initially shortening the mandible after a 20-mm-long segmental resection, followed by lengthening at a rate of 0.8 mm per day for 21 days. Eight weeks after the distraction, the device was removed and a dental implant was placed at the site of distraction. Radiographic observation showed new bone formation, and the implant was completely osseointegrated. Although the follow-up period is relatively short, the clinical course was uneventful. Distraction osteogenesis with the shortening and lengthening method seems to be a feasible option for reconstruction after segmental resection of the mandible.     

BMP-2、bFGF在牵引成骨中的表达及意义

目的 :通过两种不同术式的比较 ,研究骨形态发生蛋白 - 2 (BMP - 2 )、碱性成纤维细胞生长因子 (bFGF)的表达水平和成骨的关系 ,探讨牵引成骨的成骨机制。方法 :2 8只狗随机分为牵引成骨组和直接延长组各 12只及正常对照组 4只 ,用免疫组化染色方法观察比较BMP - 2、bFGF在两组牵引第 6天、固定 2周、固定 8周时的表达情况。结果 :两组在牵引第 6天骨断端附近的新生编织骨边缘基质及周缘的活跃的成骨细胞、骨膜下及牵开区增生活跃的间充质细胞、成纤维细胞、胶原纤维基质均可见BMP - 2、bFGF强阳性的染色 ,染色平均灰度比较均无统计学差异 (P >0 .0 5 ) ;牵引后固定 2周 ,牵引组新生编织骨边缘的成骨细胞、软骨细胞、牵开区纤维结缔组织仍可见BMP - 2、bFGF阳性染色 ,而直接延长组的BMP - 2、bFGF在牵开区的染色强度明显降低 (P <0 .0 5 ) ;牵引后固定8周 ,BMP - 2、bFGF在牵引组和直接延长组的组织中的染色强度均明显减弱 ,染色灰度比较均无统计学差异 (P >0 .0 5 )。结论 :在下颌骨牵引成骨过程中 ,在机械的牵引力和微创伤等多种因素刺激下 ,局部牵开区BMP - 2和bFGF持续高表达。两种生长因子可能共同参与促进了牵开区大量新骨的形成。     

Experimental study of mechanical analysis in mandibular lengthening. Application of strain gauge measurement

In distraction osteogenesis, the assessment of new bone formation and the decision of when to remove the distraction device are very important from clinical viewpoint. The purpose of this study was to measure bone stiffness using a strain gauge during and after mandibular lengthening, and to compare the results with those from radiographic and histological examinations. Twelve adult mongrel dogs served as the experimental subjects. An external distraction device was connected to the mandible, and distraction was started 7 days after operation and continued for 10 consecutive days. The animals underwent strain gauge measurement and radiographic examination of the mandible at the completion of distraction and every 2 weeks until the end of the consolidation period. The animals were then sacrificed at 2, 4, 6, 8, 10, and 12 weeks after completion of the distraction for histologic examinations. There was correlation between the amount of decrease in strain, increase in ratio of radiopacity, and newly formed bone in the distracted area.     

Tooth-borne distraction of the mandible. An experimental study

Two mini-pigs and 6 micropigs were fitted with a dentally fixed device for osteodistraction of the mandible. Following bilateral osteotomy and after a latency period of 7 days, the apparatus was activated 1 mm per day. A 9 mm lengthening of the mandible was achieved. After a retention period of 6 weeks, the device was removed followed by a consolidation period of 6 weeks. During the experiment, the callus and bone formation and potential dental and periodontal reactions were radiologically examined. Polychrome sequential labelling was performed by injecting calcein green and xylenol orange for histological assessment of bone. The animals were killed at the 14th postoperative week and the area of distraction and the roots of the adjacent teeth were histologically studied. After 12 weeks, the osteogenesis in the distraction gap was complete, showing lamellar bone. No detrimental effects at the roots or in the periodontium of the adjacent teeth were seen. Thus, lengthening or widening of the mandible using a tooth-borne distraction device seems feasible in selected cases.     

Enhancement of bone formation by bone morphogenetic protein-2 during alveolar distraction: an experimental study in sheep

BACKGROUND: The purpose of this study was to perform alveolar ridge augmentation by distraction osteogenesis (DO) and to enhance bone regeneration through the use of recombinant human bone morphogenetic protein-2 (rhBMP-2), followed by implant placement. METHODS: Alveolar segmental osteotomy was performed in the mandible of 10 sheep followed by placement of 1.5 mm alveolar distraction devices. The study group was injected on the fifth day of distraction with a single dose of 10 microg rhBMP-2. Only distraction was performed in the control group. RESULTS: A mean alveolar augmentation of 12 mm was achieved. After 12 weeks of consolidation, the distraction devices were removed and biopsies were taken for histological and immunohistochemical characterization and morphometry of the newly formed bone. Titanium threaded cylindrical implants were then placed in the newly augmented bone. Radiological evaluation showed lifting of the transport segment and integration of the implants within both the transport segment and the regenerated bone. The histological study demonstrated that the association of DO and BMP resulted in increased trabecular bone size and volume (32.2%+/-0.95% versus 18.6%+/-0.71%; P <1 x 10(-17) after 24 days of lengthening and 63.8%+/-1.89% versus 42.5%+/-1.33%; P<1 x 10(-15) after 12 weeks of consolidation) and increased numbers of proliferating cell nuclear antigen stained cells (0.7+/-0.04 versus 0.47+/-0.04; P<1 x 10(-10)) compared with the DO only group. CONCLUSIONS: Alveolar distraction augments atrophic alveolar ridge and creates new bone that permits implant placement. rhBMP-2 enhances bone quality and may shorten the consolidation period of distraction allowing for earlier implant placement.     

2/3 osteotomy for lengthening the mandible in dogs by gradual distraction

Successful lengthening of the mandible by gradual distraction has been reported previously. There are various methods for osteotomy before distraction osteogenesis. In this paper, a new type of osteotomy, performed on growing dogs as a model, is reported.Ten mongrel dogs, aged 6 months, were studied. A unilateral 2/3 osteotomy was performed, and an external lengthening device was fixed to the mandible perpendicular to the osteotomy. Seven days after the operation, the mandible was lengthened by 1 mm per day. The dogs were sacrificed for histological study at the end of the distraction on days 14, 28, 56 and 120 following completion of the distraction.     

口内入路个体化三焦点圆弧牵引器修复下颌骨大型缺损

目的:根据下颌骨缺损类型,设计个体化内置式圆弧牵引器,通过三焦点牵引成骨技术修复下颌骨缺损畸形。方法:对患成釉细胞瘤行下颌骨部分切除的患者,确定手术切除范围及修复后下颌骨形态,在快速原型模型上设计个体化内置式圆弧形牵引器,应用三焦点转移盘牵引方式,在肿瘤切除同期行牵引成骨手术,牵引前间歇期7d,牵引参数为0.4 mm/次,2次/d,固定期6个月。拆除牵引器后,二期行牙列修复。结果:牵引器植入后牵引过程顺利,固定6个月后X线片显示新骨形成均良好,但2个转移盘间见纤维愈合,拆除牵引器时需行钛板内固定。牙列修复前,发现下颌骨形态略小、矢状向后缩,再次行双侧下颌支矢状劈开前移下颌骨,到达设计位置并稳定后,行覆盖义齿修复。结论:个体化内置式圆弧牵引器可以有效修复下颌骨大型缺损,避免传统骨移植手术造成的供区创伤,但在前期设计时,需要适当矫枉过正。     

牙支抗羊下颌骨牵张成骨的组织学观察

目的：用自制的牙支抗骨延长装置进行羊下颌骨延长的实验研究，观察其组织学特征。方法：将9只7～9月龄山羊，实验组分4组，每组2只，对照组1只，在下颌第2和第3前磨牙之间行骨皮质切开术后，将自制的颌骨延长装置黏固于牙齿之上，术后5d开始加力，每次0．25mm，2次／d。在开始加力后分别于8、16、32、48d时将动物处死，标本进行四环素荧光标记检查、HE染色及Mallory三色染色观察。结果：四环素荧光标记结果显示：存延长区域内有黄绿色荧光标记的新骨形成；HE染色及Mallory三色染色结果显示：新骨从牵引区两侧逐渐向中央延伸，融合后的骨小梁逐渐改建成熟，纤维束、新形成的骨小梁以及早期的各种细胞均表现为长轴与牵引力的方向一致。结论：新骨有沿着牵引力方向形成与改建的组织学特点：     

牵张成骨矫治腭裂的激光共聚焦荧光定量分析

目的：利用激光共聚焦显微镜与计算机辅助荧光定量分析，研究牵张成骨术矫治腭裂新骨生成随时间间期不同的动态变化趋势，为临床矫治腭裂应用提供理论与实验依据。方法：以家猫20只为实验对象。其中18只动物建立人工腭裂实验模型。实验组（动物15只）：应用牵张成骨术，以0．4mm×2次／d的速率牵张整复封闭其腭部组织缺损。术后第2、4、6、8及12周前6d以四环素肌注标记（30mg／kg）后各取材3只动物，标本制片后激光共聚焦显微镜观察荧光沉积并进行计算机定量分析，结果与实验对照组（动物3只）及空白对照组（动物2只）对比。结果：实验组不同时间间期标本的荧光强度平均值及其总量，显示出明确的动态变化规律，自2周组起，成骨活动明显活跃，到4周组达到顶峰，至8、12周组逐渐减弱，但仍显著高出无明显荧光沉积的空白和试验对照组。结论：应用牵张成骨术移动骨运送盘封闭组织缺损，牵张间隙逐渐被膜内成骨新骨生成修复，恢复了骨连续性。随时间间期的延长，新骨逐渐改建成熟。成骨活动呈现短期达到高峰后，逐步减弱的动态变化规律。     

兔下颌骨骨膜牵张成骨的实验研究

目的 探讨骨膜牵张成骨术的新方法。方法 将自制骨膜牵张器固定于3只兔的双侧下颌骨表面,左侧行骨膜牵张,右侧不牵张,作为对照。牵张过程结束后处死所有动物,标本进行X线和组织学检查。结果 3只动物术后情况良好,无明显并发症。在大体标本和X线片上表现出新骨形成。组织学检查显示牵张区有成骨样细胞浸润和骨组织形成。结论 骨膜牵张成骨技术能够为骨缺损的修复提供一种新的方法。