牵张成骨关闭牙槽突裂的实验研究及组织学观察

目的:应用牵张成骨技术进行牙槽突裂关闭术,观测牙槽突裂硬软组织修复效果和牵张间隙新骨生成的过程、机制,探索一种牙槽突裂整复治疗的新途径。方法:以10只成年杂种犬为实验对象,建立人工上颌牙槽突裂的动物模型,其中2只为对照组。另8只为实验组,以牙骨复合体作为转运盘,以每次0.4mm,2次/天的速度沿牙弓方向行牵张成骨术,直到关闭硬组织裂隙。于原位固定0,14,28,63天分别处死动物各2只,对标本进行X线摄片、大体和组织学观察。结果:利用牵张成骨术成功地进行牙槽突裂整复术,硬组织裂隙关闭, 同时软组织得到扩张;骨牵张间隙完全被新生骨组织取代并沿牵张方向生长,随固定时间的延长改建、成熟。结论:牵张成骨术提供了牙槽突裂治疗的新途径,新骨的生成是膜内成骨方式。     

牵张成骨术修复火器伤性颌面部缺损的研究进展

颌面部属暴露部位，平战时遭受火器伤机会较多，枪弹等高速投射物击中质地硬而脆的颌面骨后，易于使之破碎，往往遗留骨性缺损，同时还会伴有软组织及牙列缺损，患者面容及咀嚼、发音等生理功能受损，如不作修复，会遗留严重面部畸形和功能、心理障碍，严重影响患者的身心健康和生存质量。牵张成骨术修复颌面部火器伤具有创伤小，效果可靠等优点，近年来受到关注。现将颌面部火器伤及牵张成骨术修复火器伤性颌面部缺损的研究进展综述如下。     

前颌中缝牵张修复牙槽裂的实验研究

目的　探索用缝牵张成骨技术以组织再生的原理修复牙槽裂。方法　采用犬牙槽裂模型 ,牙槽裂形成术后 2周 ,于前颌中缝处安置缝牵张器 ,外张力 2 0 0g。牵张 2～ 3周 ,裂隙侧的前颌骨向侧方移动贴紧远中裂缘 ,用局部黏骨膜瓣修复牙槽裂隙。保持 2周后去除缝牵张器。临床观察、连续X线、头颅干骨和组织学检查评价治疗结果。结果　所有对照动物形成规则的牙槽裂 ,无自发骨性愈合。前颌中缝牵张后 ,裂隙侧前颌缓慢向裂侧上颌靠拢 ,2～ 3周与远中裂缘密切贴合。X线片示前颌中缝呈现由窄渐宽的三角形 ,三角形的尖端指向后方 ,三角区域的骨密度逐渐增加。骨膜成形术后 3个月 ,原牙槽嵴缺损处骨质连续性完全恢复 ,且牙槽骨段在三维方向上均与对侧相同。前颌中缝恢复正常直线形态。结论　该牙槽裂模型稳定性和重复性好 ;前颌中缝牵张诱导缝区新骨形成 ,一侧前颌向裂隙移位和局部骨膜成形可达到完善的牙槽裂修复。     

扩弓后单侧完全性牙槽突裂的骨移植修复

目的:研究单侧完全性牙槽突裂畸形患者扩弓后骨移植修复的效果,为唇腭裂序列治疗后期正畸和正颌外科治疗提供临床基础。方法:对23例恒牙期单侧完全性唇腭裂术后伴发牙弓狭窄的牙槽突裂畸形患者进行快速扩弓并保持半年后,采用自体髂骨松质骨颗粒移植修复进行研究,对术后随访的X线片进行效果评价。结果:临床应用该方法治疗23例牙槽突裂患者,术后随诊3个月以上,临床观察牙槽突裂已修复,X线片显示骨密度接近正常骨质,移植骨块清晰可见,有较好的术后愈合效果。结论:正畸扩弓技术牙槽突裂骨移植修复术是唇腭裂序列治疗的重要组成部分,对于矫治伴有牙槽突裂的上牙弓缩窄畸形的唇腭裂患者,应在植骨手术前行扩弓治疗。     

唇腭侧联合入路植骨术修复牙槽突裂的临床观察

目的探讨经唇、腭侧联合入路植骨术修复牙槽突裂的临床效果。方法对收治的56例单侧牙槽突裂患者随机分为对照组(唇侧入路植骨修复)与观察组(唇、腭侧联合入路植骨修复),每组各28例。通过植入自体髂骨骨松质修复牙槽突裂,观察患者术后形态及功能变化。结果观察组植骨成功24例,成功率为85.71%;对照组植骨成功15例,成功率为53.57%。观察组患者术后疼痛及肿胀程度均低于对照组(P0.05);2组比较差异具有统计学意义(P0.05)。结论采用唇、腭侧联合入路植骨术修复牙槽突裂,术后不良反应较少,植骨成功率较高,具有临床应用价值。     

下颌骨单侧牵张成骨对下牙槽神经的影响

目的:研究下颌骨单侧牵张成骨对下牙槽神经的影响。方法:新西兰大白兔25只,24只行单侧下颌牵张,随机分为两组:一组牵张速率为0.5mm×2次/天(1mm组);另一组为0.5mm×4次/天(2mm组),间歇期均为5天,牵张长度均为10mm。在牵张完成后0周、2周、4周、8周时每组各处死3只动物,最后一只处死做对照。4%多聚甲醛灌注固定,取牵张区含下牙槽神经组织块做大体观察及组织学观察。结果:牵张区神经大体观察均可见直径变细,组织学上可见发生了不同程度的退行性变化,表现为髓鞘肿胀、层状分离和断裂、轴索数目减少,但神经外膜、束膜仍完整,随着时间延长,发生修复性变化。结论:下颌骨牵张成骨后下牙槽神经发生退行性变,但在合适的牵张速率下是可逆的,随时间延长可以完全修复。     

复合牛骨在修复牙槽突裂中的应用

目的:通过15例单侧牙槽突裂临床病例观察复合牛骨修复牙槽突裂的治疗效果。方法:随机选取15例单侧牙槽突裂的患者作为研究对象,使用复合牛骨行牙槽突裂植骨治疗。术前和术后拍摄X线片及三维CT重建,进行对比判断治疗效果。结果:15例患者无感染及骨外露情况,未见明显排异反应,均痊愈出院。术后患者外形矫正效果佳,患者鼻翼,鼻基底及患侧唇部明显上抬,达到手术预期效果。出院后1个月及4个月复查,外形良好,X线显示有明显新骨形成。结论:采用复合牛骨修复牙槽突裂,取得良好治疗效果,并且减少了因取自体骨给患者带来的手术创伤,减轻了患者的手术痛苦,同时减少了患者医疗费用。     

不同修复膜对牙种植引导骨再生的作用比较研究

目的比较分析Bio-Gide生物修复膜及博特修复膜在牙种植GBR治疗牙缺失的作用效果。方法选取2015年3月至2020年3月本院收治的牙缺损且需行牙种植GBR治疗患者共45例,治疗人员根据入院先后顺序将45例患者分为2组,其中观察组23例,行BioGide生物膜GBR治疗,对照组22例,行博特修复膜GBR治疗。结果术后半年观察组的成骨高度及厚度、水平骨生长及垂直骨生长比值均明显小于对照组(P0.05),而2组的植骨厚度及高度无明显差异(P0.05);术后半年观察组的骨生长效果明显优于对照组(P0.05)。结论在牙种植GBR术治疗牙缺失的过程中应用Bio-Gide修复膜,可以有效促进引导骨缺损处的骨再生,成骨效果更好,适合临床选择应用。     

应用牵张成骨技术修复腭裂的动物实验研究

目的:将DO技术应用于腭裂硬腭裂隙关闭,以探索一种硬腭部分成骨性修复的新方法,从而达到腭裂功能性整复的目的。方法:以1-1.5岁杂种大7只为研究对象,建立人工腭裂的动物模型。2只为对照组,只在硬腭后部形成8mm×30mm全层洞穿缺损裂隙,5只在形成缺损的同时安置DO装置,并形成骨转移盘,术后12天开始以每次0.3mm,每日2次向裂隙一侧牵张移动骨转移盘,至硬腭部软硬组织裂隙完全关闭,10周后处死动物行大体标本观察照相及X线摄片。结果:对照组10周后处死观察裂隙大小形态与手术时无差别,实验组DO装置固定牢靠、无松脱、顺利完成牵张过程,硬腭部裂隙完全关闭,骨标本及X线片示牵张区完全为新生骨组织取代,骨质厚度约0.5-1.0mm。结论:自行设计的牵张器具有稳定可靠的牵张作用,经牵张成骨能成功地完成硬腭缺损骨性修复,从而为腭裂修复提供了一种新的途径。     

牵张成骨术治疗复杂颌面骨骼缺损和畸形

目的:探讨用牵张成骨技术治疗常规方法处理困难的颌面骨骼缺损和畸形。方法:18例无法采用常规方法治疗的多类颅颌面畸形患者,分别使用外置式和内置式牵张器进行骨牵张术矫治。术前均作外科模型和必要的头影测量。术后延迟期为7天,牵张节律为lmm/天,2～4次/天,牵张结束后常规固定6～8周。结果:术后伤口正常愈合,牵张过程顺利,均达到预期牵张目的,无严重并发症发生。患者的咬合关系和面形均得到恢复。腭裂治疗后继发畸形患者最大牵张距离为20mm,最小距离为15mm;下颌骨重建患者最大牵张距离为30mm。下颌骨垂直牵张患者固定期近牵张区出现病理性骨折,但未出现错位,经内固定处理,牵张完成后,未出现畸形愈合情况或骨不连接。结论:骨牵引延长技术可以很好地适用于多种颅颌面骨畸形或骨缺损患者的治疗,尤其适用于软组织量不足、不易覆盖移植骨的患者,而且不需要另取自体骨移植。     

Limb salvage using distraction osteogenesis

Distraction osteogenesis is a novel technique for the biological restoration of segmental bone defects. Definitive treatment of musculoskeletal tumors often requires large bony resections that can leave patients with significant osseous defects. Limb salvage using distraction osteogenesis is an attractive reconstructive alternative that may, in fact, offer advantages over other conventional techniques. We present our initial experience with the use of distraction osteogenesis in limb salvage.     

Mandibular elongation and remodeling by gradual distraction. An experience of 277 cases]

Distraction osteogenesis at the craniofacial skeleton offers superior results than using standard osteotomies and other surgical techniques when treating mandibular hypoplasia. After ten years, we have performed 221 patients with hemifacial microsomia and 56 patients with micrognathia using external mandibular distraction. For every single patient the distraction vector is different according to the degree of bone hypoplasia. The bone elongation ranged from 12 to 49 mm, and the results were excellent: facial symmetry was reestablished, the menton became horizontal and the long term result controls shows stability clinically and occlusally.     

Ilizarov's distraction osteogenesis using the mono-fixator system and initial clinical experiences with the injured lower leg

Distraction osteogenesis, as developed by Ilizarov, allows the limbs to be lengthened and intercalary defects to be filled by bone transport without the use of bone grafts. In five patients with traumatic sequelae (fractures of the lower leg), unilateral dynamic mono_fixation and a special distraction apparatus were used for application of the Ilizarov technique. With the distraction device, gradual distraction of the osteotomy surfaces (1/3 mm in three steps per day) is easy for the patients to perform. In three cases distraction osteogenesis was used to correct shortening of the lower leg and in two cases for bridging a tibial defect due to an infection in the plate osteosynthesis. In all cases, the course of treatment and bone healing were uneventful. Based on our first clinical experiences, we believe that mono_fixation provides appropriate stability and the distraction apparatus permits appropriate bone transportation for successful distraction osteogenesis in the tibia.     

Novel approach to calvarial bone transport using a rabbit model

Calvarial defects sometimes require cranioplasty to protect the brain. Alloplastic materials, such as acrylic resin, hydroxyapatite ceramics, and titanium, involve various problems, such as vulnerability, infection, deformity resulting from growth, and high cost. We devised a new bone transport model in the rabbit based on the distraction osteogenesis theory of Ilizarov. Twelve Japan white rabbits with a mean body weight of 2.5 kg aged 12 weeks were used. Craniectomy (7 x 14 mm) was performed in 12 rabbits. Trapezoid bone osteotomy was performed anterior to the calvarial defect in 10 rabbits. The distraction device (Extension-plates) was fixed between the trapezoid bone island and the skull. Distraction was initiated 5 days postoperatively. The device was activated once every other day, with approximately 0.75 mm or 0.5 mm per activation. Bone distraction was continued until the rod could not be moved. The lengths of distraction were 4 mm in two cases, 5 mm in one case, 6 mm in one case, and 7 mm in two cases, with a mean of 5.5 +/- 0.56 mm. Both radiographic and histological findings showed osteogenesis by intramembranous ossification and trans-chondroid bone formation. Distraction osteogenesis has potential clinical applications in cranioplasty, especially in children because usage of autogenous bone is difficult if not impossible in most cases.     

Reconstruction of segmental mandibular defects by distraction osteogenesis for mandibular reconstruction

BACKGROUND: Distraction osteogenesis is an established technique for the lengthening of long bones and correction of selected craniofacial deformities. Regenerate osteoid bone matrix formed during the distraction phase is malleable and can recreate the three-dimensional form of native bones. Animal experiments and early clinical experience have confirmed that distraction osteogenesis can be used for the reconstruction of segmental bony defects. Herein we discuss the principles of distraction osteogenesis in reference to reconstruction of segmental bony defects and report its clinical application of the mandible continuity defects. PATIENTS AND METHODS: Four patients (age, 7-83 years) with critical segmental mandibular defects (range, 3.5 cm-6.5 cm), resulting from ablative oncologic head and neck surgery underwent primary mandibular reconstruction by transport distraction osteogenesis. Two defects were at the angle and body region, one at the body, and the other at the parasymphysis and body region. Synthes Titanium Multi-vector and Leibinger Multi-guide distractors in bifocal (n = 2) and trifocal (n = 2) architecture were used after the stabilization of the segmental continuity defect using a defect-bridging mandibular reconstruction plate. Osteodistraction was carried out at a rate of 1 mm per day, with once or twice a day rhythm, after a 1-week latency period. The consolidation period was equal to the period of distraction. RESULTS: All patients tolerated the distraction procedure. Satisfactory bone formation was observed in two patients, and partial bone formation was seen in one patient. Treatment failure was encountered in one patient who had a second oral cavity primary tumor observed during the consolidation period, requiring interruption of the treatment sequence. CONCLUSIONS: Mandibular reconstruction with distraction osteogenesis is a potentially useful technique in selected patients with segmental mandibular continuity defects after ablative head and neck cancer surgery.     

Vertikale Augmentation

Background

Vertical deficits of the bony alveolar ridge represent the most complex defect configurations, irrespective of the augmentation procedure. There are several options in implantology to compensate for vertical deficits, including guided bone regeneration (GBR), onlay and inlay techniques, distraction osteogenesis and combinations of these techniques. The technique used depends on the type of deficit.

Methods

Distraction osteogenesis has the advantage that no further bone or bone substitute has to be incorporated and that soft tissue can additionally be gained; however, a certain amount of residual bone height is necessary. The inlay technique or sandwich osteoplasty provides a good foundation for the bone or bone substitute to be inserted and can easily be incorporated due to the original vascularization of the surrounding tissues. In addition to a minimum amount of residual bone, the maximum vertical bone gain is limited by the ductility of the surrounding lingual and palatal soft tissues. For extensive vertical defects treated with the onlay technique or GBR, usually autologous bone is used resulting in additional donor site morbidity. With all these methods an experienced surgeon can achieve excellent results but individual experience plays an important role. Alternatively short implants offer the possibility to reduce the spectrum or the dimension of augmentations so that these should be included in the differential therapy and explained to patients during informed consent.

     

Distraction osteogenesis in management of composite bone and soft tissue defects

A soft tissue defect is one of the most difficult problems that may accompany bone defects. Plastic surgery is often required. During distraction osteogenesis, not only the bone but also the soft tissues are lengthened, which may help in spontaneous closure of the soft tissue defects. This study examines 11 cases of composite bone and soft tissue defects which were managed by distraction osteogenesis. After debridement of the necrotic tissues, the soft tissue defects ranged from three by four centimetres to five by 14 centimetres and the bone defects ranged from four to 12 centimetres. All the soft tissue defects healed during the process of bone transport without the need for plastic surgery, except in one case. The complications were successfully managed during the course of treatment. Distraction osteogenesis is a good method for simultaneous treatment of composite bone and soft tissue defects.     

Expression of angiogenic factors during distraction osteogenesis

Distraction osteogenesis is a unique and effective way to treat limb length inequality resulting from congenital and posttraumatic skeletal defects. However, despite its widespread clinical use, the cellular and molecular mechanisms by which this surgical treatment promotes new bone formation are not well understood. Previous studies in distraction osteogenesis have noted increased blood flow and vessel formation within the zone of distraction. These observations suggest that distraction osteogenesis may be driven in part by an angiogenic process. Using immunohistological analysis, the expression of two different angiogenic factors (VEGF and bFGF) was shown to localize at the leading edge of the distraction gap, where nascent osteogenesis was occurring. These cells were spatially adjacent to new vessels that were identified by staining for factor VIII. Microarray analysis detected maximal mRNA expression for a wide variety of angiogenic factors including angiopoietin 1 and 2, both Tie receptors, VEGF-A and -D, VEGFR2, and neuropilin 1. Expression of these factors was found to be maximal during the phase of active distraction. Expression of mRNA for extracellular matrix proteins and BMPs was also maximal during this period. A comparison between the patterns of gene expression in fracture healing and distraction osteogenesis revealed similarities; however, the expression of a number of genes showed selective expression in these two types of bone healing. These data suggest that bone formation during distraction osteogenesis is accompanied by the robust induction of factors associated with angiogenesis and support further investigations to elucidate the mechanisms by which angiogenic events promote bone repair and regeneration.     

Alveolar distraction osteogenesis of bone graft reconstructed mandible.

This case report describes a patient who had severe mandibular bony deficiency as a result of excision of aggressive central giant cell granuloma. The defect was reconstructed with iliac bone graft. Four years later vertical distraction osteogenesis was performed on the grafted mandible in order to obtain a satisfactory bony height of mandibular ridge. Distraction osteogenesis can be a good alternative for the reconstruction of mandibular deficiencies.