种植型骨牵张器的初步实验研究

目的：了解种植型骨牵张器的牵张成骨效果及骨结合情况。方法：杂种犬6只,拨除双侧下颌前磨牙,12周后随机选取一侧犬下颌牙槽嵴,矩形截骨,植入种植型骨牵张器,延迟1周后垂直牵引加高牙槽嵴,1次／d,1.05mm/次,共加力牵引4d,固定6周,并进行X线和组织学观察。结果：除一枚牙种植型牵引器因伤口感染发生松动而取出外,其余牵引器与周围组织均愈合良好,牙槽嵴平均加高4．00mm,X线显示牵引6间隙消失,牵引器的周围骨组织密合,组织学观察牵张间隙被成熟新生骨修复,牵张器－肌界面形成良好的骨性结合。结论：种植型骨牵张器可用于垂直牵张加牙槽嵴,并可发生骨结合。     

双向牵张器增高牙槽骨的实验研究

目的：自行研制一种双向牙槽骨牵张器，通过建立萎缩牙槽嵴实验动物模型，评价其应用效果。方法：实验犬8只，随机分为2组，每组4只。自行设计双向牙槽骨牵张器装置。实验动物拔除一侧下颌前磨牙1个月后，骨切开放置牵张器．间歇7d后，以1mm／d速度牵张，共牵张6d。第1组于牵张过程中逐步颊向改变移动骨段位置，第2组于牵张完成后第2天，一步颊向改变移动骨段位置至术前预定位置，2个月后对牵张区行X线及组织学检查。结果：移动骨段均达到术前预定的高度及颊向位置。牙槽骨的高度平均增加5．5mm±0．23mm，移动骨段颊侧移位平均为2．6mm±0．17mm。X线及组织学检查显示，牵张区新骨形成良好。结论：双向牵张器能在垂直向及颊舌向上精确控制牵张方向．并能在垂直牵张过程中或牵张完成后，改变移动骨段位置。避免牙槽骨牵张成骨常见的并发症：轴向移位。     

种植型弹性牵张器的研制与初步牵张实验研究

目的:设计研制新型种植型弹性牵张器。方法:采用纯钛制作中空的两段式种植型牵张器,将镍钛记忆合金弹簧置入其内,利用镍钛记忆合金的形状记忆功能所产生的回复弹力,实现自动连续牵张。在犬头颅标本的下颌骨制备3cm长,6mm高骨传送盘,植入种植型弹性牵张器,行牵张实验。结果:各加工部件符合设计要求。骨传送盘被成功牵开,稳定性可靠,牵张器无破损,可达到预期牵张效果。结论:种植型弹性牵张器机械强度高,操作简单,可实现全埋置自动连续牵张成骨,符合牵张器的发展趋势。     

牙槽骨垂直牵张后骨段颊向移位牵张成骨早期的影响

目的 研究牙槽骨垂直牵张成骨后,移动骨段一步颊向移位较大距离对牵张成骨的早期影响.方法 自行研制双向牵张器.杂种犬8只,拔除双侧下颌前磨牙1个月后,骨切开放置牵张器,间歇7d后以每天1mm的速度牵张,垂直牵张高度为6mm.垂直牵张完成后,每只犬的随机一侧作为实验侧,于牵张结束后第2天一步将移动骨段颊向移位3 mm,另...     

外置式下颌骨牵张器的研制及实验研究

目的：设计研制一种用于下颌骨的新型种植型骨牵张器。方法：采用国际标准的钛合金材料按照生物力学原理设计机械加工制成,植入山羊的下颌骨完成牵张实验。结果：山羊的下颌骨成功延长15mm,牵张器稳定性良好。结论：该牵张器结构轻巧、操作简便,克服了以往牵张器的不足,具有较高的临床应用价值。     

硬腭两维牵张器的研制及体外实验研究

目的：探讨腭骨外固定两维牵张器在腭裂修复中关闭骨裂隙和后退腭骨的可行性。方法：设计并制作两维硬腭骨牵张器，在离体犬颅骨模型上制造人工腭裂模型，根据机械移动原理和牵张成骨原理，在硬腭后部设计2块可相对移动的转移盘，在一定范围内使骨块向内和向后移动，进行两维牵张成骨，并进行了手术模拟。结果：研制的两维缝牵张器可将转移盘前后方向移动16mm，近中方向左右各移动4mm，牵张器固定牢靠，转运盘稳定，牵张控制准确，在离体模型上可实现关闭裂隙、后退硬腭的设计要求。结论：设计的外固定两维牵张器可以向后、内牵张腭骨，从而达到关闭裂隙和硬腭后退的目的。     

种植型弹性牵张器的初步实验研究

目的:探讨利用自主研发的种植型弹性牵张器增高下颌牙槽嵴的可行性。方法:选用6只成年杂种犬,随机分为实验组和对照组,拔除一侧全部前磨牙和第一磨牙。2个月后,每个传送盘内植入两枚自主研发的种植型弹性牵张器行下颌牙槽嵴牵张成骨,传送盘长3 mm,高6 mm。在牵张手术前和术后摄X片,利用X线根管测长的原理测量牵张的高度。分别在牵张完成后4周和10周处死动物,进行组织学研究。结果:下颌牙槽嵴被平均抬高4.7 mm,方向满意。X线显示牵张完成后4周牵张区骨密度增高,10周时新骨密度接近周围骨组织。组织学观察可见牵张区新骨形成良好。结论:具有自加载特性的镍钛形状记忆合金与纯钛部件相结合,为牵张器的开发提供了可尝试的新思路。     

骨牵张技术治疗下颌骨陈旧性骨折

目的：观察骨牵张技术在下颌骨骨折错位愈合二期矫治中的应用。方法：采用内置术骨牵张器治疗2例因外伤造成的下颌骨错位愈合及下颌偏斜的患者，骨牵张器每天延长颌骨约1mm，直至下颌骨体部被延长得到理想的位置。结果：2例患者受损侧的下颌骨体分别被延长11mm和7mm，无论是咬关系还是面部外形均得到明显的改善。结论：骨牵张器为治疗陈旧性颌骨骨折的继发畸形提供了可行且有效的方法。     

曲线牵张成骨的初步实验研究

目的:探讨下颌骨弧线式牵张成骨修复部分下颌骨缺损的可行性。方法:以3只大型成年犬建立实验动物模型,制造下颌骨节段性弧形缺损,植入自行研发的内置弧线式骨牵张器,牵引间歇期7 d,牵引速度0.5 mm×2次/d,固定期3个月,共牵引约30 mm,采用大体观察、X线以及组织学观察其成骨特点。结果:实验过程中无感染等不良并发症,球形传力内置弧线式骨牵张器固位始终良好,大体观察可见骨呈现弧形愈合良好,X线影像显示:牵引结束时,骨移动盘实现显著的改向、内旋的曲线移动,与远端下颌骨呈弧线连接,HE染色显示出明显的新骨形成带。结论:球形挤压传力内置弧线式骨牵张器能够实现下颌骨后段弧线式牵张成骨。     

牙槽骨垂直牵张后骨段颊向移位牵张成骨早期的影响

目的 研究牙槽骨垂直牵张成骨后,移动骨段一步颊向移位较大距离对牵张成骨的早期影响.方法 自行研制双向牵张器.杂种犬8只,拔除双侧下颌前磨牙1个月后,骨切开放置牵张器,间歇7d后以每天1mm的速度牵张,垂直牵张高度为6mm.垂直牵张完成后,每只犬的随机一侧作为实验侧,于牵张结束后第2天一步将移动骨段颊向移位3 mm,另一侧作为对照侧不改变移动骨段的颊向位置.7d后处死动物并行墨汁灌注,进行临床检查,双能X线检查牵张区骨密度,组织学检查及图像分析血管面积比率.结果 实验动物均能很好地耐受实验操作,实验侧移动骨段在垂直牵张后可较容易地颊向移位3mm,实验侧与对照侧牵张区内都有新生骨组织生成.双能X线检查显示:实验侧与对照侧的平均骨密度无统计学差异.组织学检查显示:实验侧与对照侧有平行于牵张方向的血管生成,未见明显的血管破坏,图像分析血管面积比率无统计学差异.结论 在一定范围内,牙槽骨垂直牵张后移动骨段一步颊向移位可对牵张区新生骨组织塑形,避免轴向移位.这种操作并没有明显破坏其早期的血管生成及成骨潜能.     

Endosseous implants in horizontal alveolar ridge distraction osteogenesis

PURPOSE: This study evaluated horizontal distraction of the narrow alveolar ridge in dogs and the possibility of achieving osseointegration of implants placed into the distracted site during a consolidation period. MATERIALS AND METHODS: Six beagle dogs weighing approximately 9 to 10 kg were used in this experiment. Twelve weeks after extraction of the mandibular premolars, horizontal alveolar ridge distraction was performed using an originally designed lengthening apparatus. Twelve days after the completion of distraction, screw-type implants were placed into the distracted site. RESULTS: Twelve weeks after the placement of implants, thin lamellar bone rose horizontally from the transport segment toward the surface of the implant. Twenty-four weeks after their placement, the implants were fully embedded in mature lamellar bone, and direct bone contact with the implant surface could be seen. DISCUSSION: Horizontal alveolar ridge distraction was performed successfully by using a lengthening apparatus in the narrow alveolar models. Osseointegration was achieved even though the implants were placed into the distracted site during the consolidation period. CONCLUSION: Horizontal alveolar ridge distraction can be a beneficial technique in the placement of implants In the narrow alveolar ridge in the dog population.     

Distraction implants: a new operative technique for alveolar ridge augmentation.

In the past alveolar ridge augmentation was mainly based on autologous or allogenic bone transplants. Since 1996 alveolar ridge distraction has enabled local osseous build-up without bone transplantation. The 'distraction implant', uniting qualities of a distraction apparatus with those of a dental implant, has been in use for three years at the Department of Oral and Maxillofacial Surgery of Graz University. Its application in patients with alveolar ridge atrophy and other defects is demonstrated and the first results are presented in this study. Three patients with severe alveolar ridge atrophy of the edentulous mandible, three with extensive alveolar ridge defects and three with local alveolar defects following traumatic loss of a single tooth were treated with distraction implants. Segmental osteotomy was carried out in all patients and one or two distraction implants were positioned. Following this alveolar ridge distraction was carried out. In seven cases there were no complications, whereas in one patient distraction was discontinued, and altogether two distraction implants had to be removed. All complications were treated by conventional operative techniques. Fifteen of 17 distraction implants were loaded successfully. Alveolar ridge distraction by means of distraction implants is an adequate method of alveolar ridge augmentation resulting in improved implant sites and gingival conditions. The segment for distraction should not be smaller than an upper central incisor. The implants can be used for prosthetic treatment, but long-term results are still not finalised.     

Use of horizontal alveolar distraction osteogenesis for implant placement in a narrow alveolar ridge: a case report

Although alveolar distraction is a promising method for ridge augmentation involving the atrophic maxilla or mandible for implant placement, techniques of horizontal and oblique alveolar distraction for expanding a narrow alveolar ridge have not been established. A case of horizontal alveolar distraction for implant placement using a titanium mesh plate and a distraction screw is reported. Horizontal alveolar distraction was performed on a patient with an extremely atrophic alveolar ridge in the anterior mandibular region. Two transport segments using horizontal osteotomies were prepared, and 2 horizontal alveolar distraction devices were inserted. After a 7-day waiting period, the devices were activated and alveolar widening was performed labially (0.225 mm twice a day for 14 consecutive days). Three months after consolidation, the distraction devices were removed. The distracted areas were completely filled with newly formed solid bone tissue. Two months after the device was removed, 4 endosseous implants were placed and an implant-supported definitive prosthesis was placed. This method of horizontal alveolar distraction appears to be clinically useful for the placement of implants in atrophic or knife-edged alveolar ridges.     

Vertical alveolar bone distraction at molar region using lag screw principle.

PURPOSE: Recently, alveolar bone distraction has been widely used and several devices have been developed for this purpose. However, there are some disadvantages in each device, especially for distraction of posterior alveolar ridge. The purpose of this study was to develop a new device for vertical alveolar bone distraction at the molar region and to show the results of its clinical application. MATERIALS AND METHODS: The mechanism of device is based on lag screw principle and the device consists of the following 4 components; distraction screw, hole implant fixture, supporting plate, and temporary short implant and/or neighboring natural teeth. The distraction screw suspended at the supporting plate is inserted into the internal thread of the hole implant fixture placed at alveolar transport segment. If the distraction screw turns at the supporting plate, the hole implant fixture with transport segment moves to the supporting plate without vertical movement of the screw at the supporting plate like a lag screw. After an animal experiment using 4 beagle dogs, the device was clinically applied in 4 patients before implant insertion. RESULTS: The distraction of the alveolar bone could be successfully performed in all patients without any complications. The direction of distraction with this device could be adjustable, and the alveolar bone could be distracted not only vertically but also horizontally. Moreover, the surgical technique is simple with no need for a second surgery, and there is no occlusal disturbance from the device. CONCLUSIONS: The new device for alveolar bone distraction using lag screw principle can be used effectively in the molar region.     

Evaluation of distraction implants for prosthetic treatment after vertical alveolar ridge distraction: a clinical investigation

PURPOSE: The purpose of this study was to clinically evaluate the mucosal condition and the esthetic and functional results of distraction implants loaded with fixed or removable implant-supported restorations. MATERIALS AND METHODS: A total of 35 patients were treated with 62 distraction implants for correction of alveolar ridge deficiency. The distraction implants were loaded with prosthetic superstructures 4 to 6 months after distraction. Nine patients were provided with single-crown restorations, 16 received metal-ceramic fixed partial dentures, and 10 received removable overdentures. Recall was scheduled before and 3, 6, and 9 months after implant loading. Periotest values, periimplant probing depths, and radiographic marginal bone levels were recorded, along with any biologic or mechanical complications. RESULTS: Patients were followed for 9 months after implant loading. Two distraction implants were lost before abutment connection. After fabrication and placement of individual abutments, all implants were loaded with prosthetic superstructures. The results showed a decrease of the Periotest values, and thus an increase of implant stability, during the following 9 months. Periimplant probing depths also decreased in the first months after implant loading. Soft tissue around the superstructures and adjacent teeth was healthy. CONCLUSION: The distraction implant system has a high potential for osseointegration. Because of the gentle distraction technique and the possibility of using individual abutments at almost any angulation, satisfying esthetic and functional results are possible. The rate of complications was low in this short-term study.     

Histologic and radiographic evidence of vertical ridge augmentation utilizing distraction osteogenesis: 10 consecutively placed distractors

BACKGROUND: Vertical ridge augmentation for dental implant placement is one of the greatest challenges facing the surgeon. Inadequate vertical bone compromises the implant positioning and resulting restoration. The cleansibility, esthetics, and mechanical properties of the restoration can all be compromised. While the technique of distraction osteogenesis has been successfully employed for long bone applications for over 40 years, it has only recently been introduced as a technique for vertical ridge augmentation prior to dental implant reconstruction. METHODS: In this study, the placement of 10 consecutive distractors in 7 patients was evaluated. The surgical technique, latency period, distraction rate, and consolidation period are reviewed. RESULTS: The technique of distraction osteogenesis resulted in an average vertical augmentation of 7 mm, with a range of 5 to 9 mm. There were no complications affecting the outcome of the distraction procedure. No failures have occurred to date in the 16 implants that were placed and loaded following distraction. CONCLUSIONS: In summary, clinical, histologic, and radiographic evidence of consistent vertical bone augmentation was found with this technique of distraction osteogenesis for vertical ridge augmentation.     

外置式兔下颌骨牵张器的设计及其在动物实验研究中的应用

目的：报告自行研究开发的外置式兔下颌骨牵张器．探讨其用于动物实验的可行性方法：10只新西兰兔，采用外置式牵张器，牵张延长下颌骨，并进行X线及组织学观察。结果：牵张器成功延长兔下颌骨1cm,稳定性良好。结论：此牵张器结构简单，操作方便，适合在动物实验中应用.     

Alveolar distraction before insertion of dental implants in the posterior mandible

We investigated the efficacy of alveolar distraction for reducing crown height:implant length ratio in the posterior mandible. Ten alveolar distractions were done in seven patients. The pre-distraction ratio of required crown height to bone height available for implantation was in all cases > or =1. Two implants were placed in each distracted area (total 20 implants). Before distraction, the mean (SD) predicted crown height was 12.8 (2.1) mm; mean bone height available for implantation was 7.8 (1.5) mm. After distraction and insertion of implants, mean crown height was 8.1 (1.9) mm, and mean implant length was 11.3 (1.9) mm. Before distraction, the mean required crown height:available bone height ratio was 1.7 (0.3); after distraction and insertion of implants, the mean crown:implant ratio was 0.7 (0.2) (P<0.0005). Alveolar distraction is effective for increasing the height of the alveolar ridge in the posterior mandibular region, and should be considered when the height of the predicted crown that is required is greater than or equal to the maximum height of bone available for implantation.