下颌骨正中牵引成骨系统有限元模型的建立

目的:建立使用3种不同牵引器(牙支持式、骨支持式和混合支持式)的下颌骨正中牵引成骨系统的有限元模型。方法:使用人体颌面部标准解剖模型,通过激光扫描,建立下颌骨、牙列和颞下颌关节盘的三维几何模型。描绘出颞下颌关节囊轮廓并生成关节囊几何模型。将下颌骨几何模型和3种牵引器简化几何模型导入有限元建模软件中,建立3种牵引器的下颌骨正中牵引成骨系统的有限元模型。结果:成功建立了使用3种牵引器下,颞下颌关节可自行旋转的下颌骨正中牵引成骨的有限元模型。结论:该模型仿真程度高,接近临床实际,为后续研究下颌骨正中牵引成骨对颞下颌关节的生物力学影响,提供了良好的实验平台。     

建立管状骨增宽牵引同期种植的动物模型

目的 建立管状骨增宽牵引同期种植的实验动物模型,研究管状骨增宽牵引同期种植后的组织学变化,为临床应用提供依据.方法 采用成年山羊12只,分为实验组(9只)、对照组(3只).12只动物均在左后肢胫骨手术安放2只种植牵引装置.实验组术后1周开始牵引,0.35 mm/次,2次/d.通过影像学、组织形态学方法评价牵引后的不同时期管状骨增宽牵引成骨新骨的形成情况;对照组术后不牵引.结果 实验组胫骨增宽牵引后平均增宽7.83 mm.数字减影血管造影术(djgital subtraction angiography,DSA)评价结果显示:实验组与对照组胫骨与腓骨的供血血管相似,行走于胫骨的后外侧,伴行胫骨的全程,与胫骨的关系密切.X线观察显示:实验组牵引间隙逐渐模糊,牵引结束后3个月时牵引间隙充满新骨.组织形态学结果表明:牵引间隙两侧的成骨结果不一致,种植体骨整合仅发生在有螺纹部位的种植体;而牵引移动的种植体尾部有纤维组织包绕.结论 山羊胫骨的解剖以及血液供应与人类的腓骨相似,是研究人类腓骨种植同期增宽牵引理想的实验模型.     

影响牵引成骨术的若干因素

牵引成骨(distraction osteogenesis,DO)技术由于其良好的效果和难以替代的优点已成为治疗四肢骨和颅面骨缺损和发育不良的重要技术。疗程长是DO的主要缺点,为此众多学者用不同方法对DO过程干预,得到很多有意义的结果。     

牵引成骨术与骨生长因子

牵引成骨术用于颅凳面畸形矫正已越来越受到欢迎。牵引新骨的形成受多种骨生长因子的调控。作者综述了牵引成骨术中各种生长因素的表达及外源性因子对骨再生的作用。     

内置式下颌骨牵引成骨术的早期并发症及防治

目的 总结内置式下颌骨牵引成骨术(DO)术中和术后早期并发症，探讨其有效防治方法。方法 对1997年11月～2002年12月间应用DO治疗的48例(83侧)下颌骨畸形或缺损患者进行分析。其中颞下颌关节强直伴小颌畸形双侧13例、单侧9例，下颌骨发育不足或小颌畸形14例，第一、二鳃弓综合征单侧5例、双侧1例，爆炸伤或肿瘤术后缺损畸形5例，Treacher Colins综合征1例，伴睡眠呼吸暂停综合征(OSAHS)者19例。所有病例均采用口内或(联合)口外切口并应用内置式牵引器。总结自施行手术开始至牵引完成期间的并发症及处理措施。结果 6例患者出现术中或术后早期并发症，发生率为12．5％，其中牵引机械装置故障2例，骨皮质切开术不彻底1例，早期感染1例，前牙严重开He1例，牵引早期疼痛剧烈1例，积极处理后均达到预期治疗目的。结论 减少DO术中及术后早期并发症的关键在于充分理解下颌骨牵引成骨术的机理，熟悉掌握下颌骨及邻近解剖结构，熟练操作规范，充分的术前准备和术后护理尤为重要。     

不同牵引速率的牙周膜牵引成骨快速牙移动动物模型的建立

目的建立固定牵引频率与不同牵引速率组合的牙周膜牵引成骨快速牙移动的动物实验模型,探讨在牵引频率一定情况下的最适牵引速率。方法将6只犬的下颌左右两侧随机分组,按每天牵引速率分为0.2、0.6、1.0 mm/d三组。拔除下颌第一前磨牙后行凿骨减阻,用自制牵引装置进行牵引,固定牵引频率1次/天,每组分别以不同的牵引速率(0.2、0.6、1.0mm/d)进行牵引,牵引1周后维持3 d。测量每组支抗牙、移动牙移动距离;取材行光镜观察。结果在固定牵引频率为1次/天的条件下,1.0 mm/d组移动牙移动距离最大,0.6 mm/d组次之,0.2 mm/d组最小。组织学结果显示:0.6 mm/d组、0.2mm/d组牙周膜改建活跃,1.0 mm/d组牙周纤维断裂,牙周组织水肿。结论牙周膜牵引成骨可以加快牙齿移动速度,且随着牵引速率的增大,牙齿移动速度也相应加快,但存在一定限度。     

山羊双侧下颌骨牵引成骨动物模型的建立

目的:建立一个可行性良好的山羊下颌骨牵引成骨模型。方法:将6只山羊的下颌骨截断,安置牵引器,延迟期4 d后以0.5 mm/次,2次/d的速度牵引10 d;随后进入固定期。分别于固定期的2、4、6、8周处死动物,进行大体标本和放射学观察。结果:牵引过程被所有山羊耐受,牵引长度达到预期效果。结论:山羊是一种良好的牵引成骨动物模型;该模型有助于DO临床的应用及研究。     

兔成骨细胞体外培养及自体肌内成骨的实验研究

目的 :建立一种体外培养兔成骨细胞的生物学模型 ,并对其生物学特性及体内成骨能力进行研究。方法 :抽取日本大耳白兔骨髓液经离心后得骨髓单个核细胞 ,以1×106/ml的细胞浓度进行培养 ,经传代培养 ,通过倒置显微镜、HE染色、扫描电镜、透射电镜、碱磷酸酶 (alkalinephosphatase,ALP)染色、Ⅰ型胶原免疫组化染色和VonKossa钙染色等手段对获得的细胞进行生物学特性研究。然后将细胞与载体材料—膨体聚四氟乙烯(ePTFe)复合培养1周后回植自体兔肌肉内 ,4周、8周后分别取材 ,组织学方法观察其成骨能力。结果 :培养的细胞形态多样 ,呈集落样生长 ,可相互重叠成复层状 ,胞浆富含线粒体、粗面内质网和高尔基体 ,胞浆突起长短、粗细不等 ,互相连接。培养细胞富含ALP活性Ⅰ型胶原和VonKossa染色均阳性。这与典型成骨细胞的生物学特性相似。成骨细胞经体外增殖 ,与载体复合培养后生长良好。植入体内早期(4周时 )形成的骨基质结构疏松 ,周围仍有较多成骨细胞 ,晚期 (8周时 )则可见形成的骨样组织结构致密 ,内有骨细胞位于骨陷窝中 ,与典型的骨组织结构相似。结论 :用兔骨髓基质细胞在体外筛选、培养成骨细胞的方法是可行的     

骨形成蛋白家族与牵引成骨术

牵引成骨术(DO)中新骨的形成具有胚胎骨的发生和正常骨折愈合的某些特征,骨形成蛋白家族(BMPs)在其中扮演了重要角色。本文就BMPs与DO的生物学联系、作用调节机制、外源性BMPs的应用等方面作一综述。     

牙槽骨垂直牵引成骨种植术的临床研究

目的 评价牙槽骨垂直牵引成骨技术在改善种植区域骨量中的可行性、临床效果及优缺点。方法 19例因肿瘤切除术或外伤等原因造成重度牙槽突垂直向骨缺损（缺损均大于10mm)患者接受了垂直骨牵引术，其中男性15例，女性4例，平均年龄35岁。常规行术前、术后及牵引前、后X线检查记录及取牵引器时直接测量牵引高度。安放牵引器7d后开始牵引，每日牵引1mm至设计高度。保留牵引器2－3个月，局麻下拆除牵引器，植入种植体。结果 19例中11例已完成种植上部结构修复，已植入种植体尚未完成上部修复6例，共植入种植体65枚。19例在牵引成骨后均形成理想新骨，平均新生骨的高度13mm。牵引区意外骨折2例，牵引区感染1例，植入种植体后感染1例。结论 牙槽骨垂直牵引术是解决重度骨量不足的有效的替代方法。     

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。     

Two-stage maxillary distraction osteogenesis using a modified external device: clinical outcome and complications

Rigid external distraction is currently used to correct severe maxillary hypoplasia. The purpose of this retrospective study was to present the clinical results and complications of a two-stage surgical approach using a modified external distraction system that consists of maxillary distraction and then maxillary fixation. We treated eight patients with cleft lip and palate in this way from 2016 to 2018. Lateral cephalograms taken before the first operation, after distraction, two weeks after the second operation, and one year after treatment were used to examine maxillofacial morphology. Velopharyngeal function was evaluated by a speech therapist. The mean movements of the maxilla forwards and downwards at Point A were 12.0 mm and 8.0 mm at the completion of distraction and those at Point B were 5.0 mm backwards and 9.7 mm downwards. Mouth opening was limited at this time, and was relieved after maxillary fixation. The mean relapse one year postoperatively was 24.3% horizontally and 52.5% vertically. Velopharyngeal function was unchanged by the operation. We conclude that the method has advantages that include the short duration of wearing distractors and increased acceptance by patients. The modified external device advanced the midface sufficiently.     

Development of a device for the delivery of agents to bone during distraction osteogenesis

Various agents have been theoretically and experimentally implicated as mediators of distraction osteogenesis (DO). The purpose of this study was to develop a vehicle for the potential delivery of these factors to the region of the distraction site in an attempt to manipulate this biologic process. Three adult mongrel dogs (12 months old) had oblique osteotomies performed bilaterally through the gonial regions. In group I, the external distracter was affixed to the right hemimandible of two dogs (n = 2 hemimandibles) with cannulated pins (external diameter = 1.5 mm; lumen diameter = 1.0 mm; length = 60 mm), whereas the distracter on the left was affixed with standard, noncannulated pins of the same dimensions. In group II, cannulated pins were used to affix the external distracter to both hemimandibles (n = 2 hemimandibles) of a dog. The devices were activated after a 5-day latency period and were lengthened at a rate of 1 mm/day for 20 days. During the distraction period, 0.1 ml/d of sterile india ink was injected into the cannulated pins, after which the sterile stylet was replaced. The activation protocol was followed by 28 days of fixation (consolidation period). The hemimandibles from group I underwent removal of soft tissues, acetone fixation, and gross examination/photography, whereas the hemimandibles from group II were prepared for histologic evaluation (whole mount, hematoxylin and eosin staining). All dogs survived to the end of the study and demonstrated successful DO without evidence of complications. Hemimandibles in group I displayed evidence of india ink on both the lingual and buccal cortex around the cannulated pin site, in the regenerate and on the neocortices of the distracted segment. Hemimandibles of group II showed histologic evidence of the india ink being deposited densely around the cannulated pin site and extending in a radial fashion around the pin site into the regenerate. This study demonstrates for the first time a vehicle device for the delivery of an inert dye to the regenerate site during distraction osteogenesis. This vehicle offers the potential of delivery of various factors implicated in distraction osteogenesis (i.e., mitogens) in an attempt to alter this process and also substances (i.e., chemotherapy, antibiotics, etc.) for use in the treatment of various osteopathies.     

BMP-2和OPG在腭横缝牵引中的表达

目的：了解腭横缝牵张成骨中骨形成蛋白2（BMP-2）和护骨素（OPG）的表达，探讨持续牵引力对骨改建的调控过程。方法：以杂种犬16只为实验动物，实验组在腭横缝及额上颌缝安置内置式镍钛合金牵引器。空白对照组不处理。术后10、20、30、40d切取腭横缝组织，行组织学观察。结果：实验组上颌骨成功前移，BMP-2、OPG阳性染色主要定位于成骨细胞中。结论：缝牵引可以顺利扩张生长期上颌骨，其成骨方式是膜内成骨；BMP-2可以诱导和激发成骨细胞活性，OPG在骨吸收过程中起重要调控作用。     

Combined simultaneous distraction osteogenesis of the maxilla and mandible using a single distraction device in hemifacial microsomia

Facial asymmetry in hemifacial microsomia can be corrected by an effective procedure of gradual distraction of the mandible. In younger children with deciduous dentition, changes in dental occlusion secondary from mandibular distraction can be easily corrected with orthodontic treatment. In older patients, mandibular elongation through distraction osteogenesis can produce good aesthetics but can create a severe alteration in occlusion requiring complex orthodontic treatment during an extended period. A Le Fort I osteotomy was performed simultaneously with mandibular corticotomy to avoid this problem. We present an 11-year-old patient with grade II hemifacial microsomia with facial asymmetry that was corrected with a combined simultaneous distraction of the maxilla and mandible using a single mandibular distraction device and an interdental splint. Excellent facial symmetry was achieved while maintaining preexisting dental occlusion.     

颞下颌关节紊乱病动物模型的建立及其评价

目的探讨经颧弓后上牵引下颌，建立颞下颌关节紊乱病（TMD）动物模型的可能性。方法21只新西兰大白兔（实验组15只，对照组6只），单侧经颧弓后上牵引下颌，观察关节盘、关节间隙及关节软骨的组织病理学改变。结果实验组术后2周4只动物关节盘移位或变形；4周时5只动物关节均发生粘连，关节软骨发生不同程度表层破裂、缺损或排列紊乱；6周时4只动物关节盘严重变形，5只动物关节发生严重粘连，骨小梁排列紊乱。对照组均正常。结论经颧弓后上牵引下颌是研究TMD病理机制一种较可靠的动物模型。     

Innovation in anterior mandibular alveolar distraction osteogenesis: Introduction of a new bone-borne distraction device and first clinical results

Segmental distraction osteogenesis of the anterior mandibular alveolar process (frontblock) is a sufficient method to avoid extractions in patients with dental crowding and to decompensate retroalveolism. Up to now dental-borne devices were used, but limitate the indications for front-block distraction.A new bone-borne distraction device for mandibular alveolar front-block movement is introduced in this study. The distractor allows sufficient segmental transport without loading on the teeth. Clinical evaluations of 7 patients have been performed including the feasibility and predictability of the distraction, postoperative pain and patients’ discomfort. The results indicate that this technique is a promising strategy in the correction of dental crowding, correcting the curve of Spee and to decompensate mandibular retroalveolism even in patients with impaired periodontal health and a thin mandibular symphysis.     

牵引成骨过程中前列腺素E2的表达及其作用

目的观察牵引成骨过程前列腺素E2的变化与表达。方法通过组织化学、免疫组化、放射免疫等方法检测牵引成骨过程前列腺素E2的变化和表达。结果牵引成骨过程前列腺素E2表达增高。结论前列腺素E2参与了骨牵引过程新骨生成的调节，PGE2的变化与牵引成骨机制密切相关。     

钛-镍记忆合金牵张成骨的新生骨骨密度及生物力学测试

目的通过对牵张成骨新生骨的骨密度和生物力学测试，研究钛-镍记忆合金牵张器牵张成骨的质量。方法选用成年杂种犬12只，下颌两侧拔牙后用全埋置钛-镍记忆合金牵张器完成牵张手术，左侧为实验侧，右侧为自身对照。分别在牵张完成后3、6个月进行双能x线骨密度测量和压缩生物力学测试。结果术后3个月，牵张区新生骨骨密度、抗压强度、弹性模量低于对照侧；6个月，各项指标均有增加，与对照侧的差异无统计学意义。结论用钛-镍记忆合金牵张器牵张，增高犬下颌后牙区牙槽嵴，新生骨质量可以满足种植等后期修复的要求。