种植体牵张成骨增高牙槽嵴的动物实验研究——形态学观测

目的 :采用多种形态学测量方法研究种植体作为牵张装置增高牙槽嵴的可行性。方法 :杂交家犬6只 ,随机分为3组。拔除犬所有的前磨牙 ,3月后在下颌前磨牙区施种植体牵张成骨增高牙槽嵴术 ,术后4周、9周、14周取材 ,进行大体观察、放射检查、电镜及计算机定量组织学研究。结果 :采用种植体牵张成骨增高牙槽嵴2.83mm±0.42mm ,种植体在骨升段与牵张段骨接触率基本接近 ,无统计学意义。结论 :同期种植体植入并牵张成骨技术是增高牙槽嵴的一种良好的方法 ,在临床上应有广阔的应用前景。     

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。     

种植体牵张成骨增高牙槽嵴的动物实验研究——组织学观察

目的：从组织学角度研究种植体作为牵张装置增高槽嵴应用的可行性。方法：杂交家犬６只,随机分为３组,拔除所有的前磨牙。３月后在下颌前磨牙区施种植体牵张成骨增高牙槽嵴术,要后４周、９周、１４周取标本,进行脱钙这检查和非脱钙这检查。结果：术后１４周牵张区形成成熟的骨小梁及骨皮质,种植种为骨性结合。结论：种植体牵张成骨增高牙槽嵴术可应用于临床。     

后牙区下颌骨高度的测量

牵张成骨技术于 2 0世纪 90年代后期开始应用于牙槽嵴增高 ,无论是牵张方法的研究还是牵张器的设计都需充分了解患者牙槽嵴丧失情况。至今对后牙区下颌骨吸收量及牙槽嵴需增加高度尚无确切的定量资料。我们测量下颌骨标本及临床患者曲面体层片 ,以期为下颌后牙区牙槽嵴增高术提供定量参考指标。1 材料 :89具成人离体下颌骨标本 ,性别不详 ,牙列完整者 6 5具 ,无牙颌 14具 ,后牙列缺失 (尖牙以后牙列缺失 )10具。 90张曲面体层片符合下列条件 :① 5 0岁以上患者 ;②有牙颌患者且牙列完整 ,颌关系正常 ;③下颌骨体无明显扭曲变形 ,左右基本对…     

应用钛种植体牵引增高牙槽嵴的实验研究

在行传统或种植义齿治疗的患者中,Ⅴ或Ⅵ类下颌骨常需行牙槽嵴增高。增高牙槽嵴的方法很多,但各有优缺点。骨移植需供区取骨,且可能发生骨吸收;引导骨组织再生仅适合于局限性牙槽嵴缺损修复;异体材料因其内在的问题不适合于放置种植体。本文旨在应用牵引成骨的原理,探讨种植体牵引增高牙槽嵴的可行性。 材料和方法 选取5只成年健康杂种狗,全麻下拔除左下颌前磨牙,并以牙槽成形术降低牙槽高度,形成牙槽嵴萎缩模型。12周后,自尖牙远中至第一磨牙     

使用钛镍记忆合金牵张器时截骨方式的选择

目的　比较不同截骨方式对钛镍记忆合金牵张器牵张增高牙槽嵴的影响。方法　 10只成年杂种犬随机分为 3组。Ⅰ组截骨时保留舌侧部分骨皮质 ,Ⅱ组完全截骨 ,使用牵张器增高牙槽嵴 ;Ⅲ组为内固定器对照组。各组动物下颌骨左侧为实验侧 ,右侧为空白对照侧。连续测量术区颌骨高度 ,摄X线片 ,3个月后处死动物 ,进行组织学观察。结果　Ⅰ、Ⅱ组牙槽嵴均增高 ,3个月时牵张区骨密度与周围牙槽骨接近。Ⅱ组比Ⅰ组初始牵张间隙大 ,增高高度大 ,但牵张区颊舌侧均有较明显凹陷 ,而Ⅰ组牵张区形态接近正常颌骨。结论　采用保留舌侧部分骨皮质的不完全截骨方式 ,更适于使用记忆合金牵张器的牙槽嵴增高术     

钛镍记忆合金牵张器牵张增高牙槽嵴后的种植修复

目的探讨TiNi-SMA牵张器牵张增高的牙槽嵴能否进行常规种植修复。方法6只成年杂种犬进行牙槽嵴牵张增高术,3个月后随机分为2组。Ⅰ组为牵张种植组,牵张侧及对照侧下颌骨各植入2个种植体;Ⅱ组为牵张对照组,不进行种植手术。在种植手术前、术后、术后3个月拍X线片,动物处死后截取骨块制作常规脱钙切片和带金属种植体的骨组织磨片进行组织学研究,并测量种植体-骨接触率。结果种植后3个月X线片可见各种植体与骨之间均无放射线透射区,种植体整合良好。种植体-骨界面表现为骨性结合,牵张侧与对照侧的种植体-骨接触率相比较差异无显著性。结论应用TiNi-SMA牵张器增高的牙槽嵴在牵张完成后3个月可以进行常规种植手术,种植体-骨结合良好。     

应用钛镍记忆合金牵张成骨增高下颌牙槽嵴的初步研究

目的 探讨应用钛镍记忆合金牵张成骨增高下颌牙槽嵴的可行性。方法 选用成年杂种犬10只，拔除两侧下颌全部前磨牙和第1磨牙，实验组1个月后用完全埋置的钛镍记忆合金牵张器完成牵张手术。在牵张手术前及术后1、5、13周测量术区颌骨高度，拍X线片，分别在牵张完成后1、3个月处死动物，进行组织学研究。结果 牵张器就位后骨块即开始牵张升起，术后1周达7．5～11．5mm，其后无明显变化。X线片可见牵张完成后1个月牵张区骨密度增高，有新骨生成；3个月骨密度与周围牙槽骨接近。组织学观察牵张区早期有胶原束形成，随后钙化成骨。结论 用钛镍记忆合金牵张器可成功牵张增高犬下颌后牙区牙槽嵴，新骨以膜内成骨方式生成。     

绵羊牙槽嵴牵张术后的愈合

利用牵张牙槽嵴来增高下颌体的方法已使用了多年。自1996年以来,奥地利格拉茨大学口腔颌面外科将牵张器植入牙槽嵴内牵张下颌骨,牵张结束后保留在牙槽嵴内,牵张器被改造成螺旋形牙种植体的形状用于以后的修复(图1)。本文目的是介绍这种牵张器在动物实验中的应用,并对牵张术后的愈合过程进行跟踪观察。     

下颌前部垂直牵张成骨在种植义齿中的临床应用

目的应用牵张成骨技术治疗下颌前部牙槽骨垂直高度不足,并进行种植义齿治疗下前牙缺失。方法应用国产骨牵张器对3例外伤后多个前牙缺失伴有严重骨缺损、骨高度不足的患者进行下颌前部垂直牵张成骨,牵引增高下颌骨至理想的高度并固定2个月后,去除骨牵张器,同期植入牙种植体,术后3个月完成种植修复。结果3例患者骨牵张手术伤口愈合良好,牵引顺利,平均牵引增高下颌骨8.2 mm。X线检查牵引骨块生长良好,无明显骨吸收。二期手术时未见明显感染,固定骨和牵引骨之间的间隙内充满了新生骨,牵引骨块稳固。共植入骨内种植体14颗,3个月后完成种植二期手术和种植修复。1年后复查,种植体稳固,咬合功能良好,外形满意。结论牵张成骨技术是治疗下颌骨前部严重骨缺损牙槽骨高度明显不足一项非常有效的方法,可以为牙种植术提供足够的骨量。在此基础上及时进行下颌前牙区种植义齿修复临床疗效满意。     

Experimental alveolar ridge augmentation by distraction osteogenesis using a simple device that permits secondary implant placement

The purpose of this study was to develop an improved technique of alveolar ridge augmentation by distraction osteogenesis using distraction screws, and to investigate tissue reactions to titanium implants at the distraction site. The left mandibular premolars were extracted from 6 adult dogs. After 12 weeks, a box-shaped osteotomy of the alveolar bone was carried out, and distraction devices were placed on the transport and base segments. After a 7-day latency period, the alveolar bone was augmented by 7 mm vertically at a rate of 1.0 mm/day. Just after distraction, these devices were replaced with dental implants for fixation of the transport segment and bone formation of the distraction site. Histologic and radiographic evaluations were made at 8 and 12 weeks after distraction. Vertical augmentation averaged 6.1 mm after 12 weeks of consolidation. It was possible to lengthen the alveolar bone without great difficulty, and good bone formation was recognized in the distraction site. Greater integration between the implant and the distracted bone was observed at 12 weeks after distraction than at 8 weeks. Distraction osteogenesis was successfully applied to alveolar ridge augmentation by this improved technique, and the implants osseointegrated in the augmented ridge.     

Loaded hydroxylapatite-coated implants and uncoated titanium-threaded implants in distracted dog alveolar ridges

AIMS: The aim of this study was to determine the response of alveolar bone after it was augmented vertically with distraction osteogenesis, implanted with hydroxylapatite (HA)-coated implants and noncoated titanium-threaded implants, and subsequently loaded for 1 year. METHODS: Eight dogs each had 4 implants placed horizontally into an edentulous mandibular quadrant. After integration, a distraction osteogenesis device was fabricated in the laboratory. An osteotomy was made to allow the crest of the alveolar ridge to be distracted vertically. After 10 mm of vertical distraction, the distraction devices were stabilized with light cured resin. After bone fill of the distraction gap was radiographically confirmed in all dogs at 10 weeks, 2 implants were placed into the ridges. Four dogs had threaded titanium implants placed, and 4 dogs had threaded HA-coated implants placed, with 1 implant in the distracted bone and 1 implant in adjacent nondistracted bone, for both groups. After 4 months for implant integration, bridges were fabricated and secured to the implants with screws. Crestal bone levels were evaluated by radiographs through 1 year of function. Animals were killed after 1 year of loading for histologic evaluation. RESULTS: The vertical ridge augmentation averaged 8.8 +/- 1.0 mm after 10 weeks of healing after distraction. Analysis of variance indicated a significantly greater change from baseline for HA-coated implants and for distracted bone sites. Histologic examination showed that bone had formed between the distracted segments creating an augmented ridge. The average thickness of the labial cortex in the distraction gap was significantly thinner than the lingual cortex in distracted bone or the lingual and labial nondistracted cortical bone. The presence of a dental implant did not significantly affect cortical bone thickness. Serial sections showed that implants remained integrated and functional without soft tissue inflammation. CONCLUSION: Dental implants placed into alveolar ridges augmented with the technique of distraction osteogenesis were functional for the length of this study.     

Study of mandibular alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method: report of four patients, a preliminary study

OBJECTIVE: This study was conducted to show dimensional and volumetric changes after vertical alveolar distraction osteogenesis using a three-dimensional computed tomography measurement method. MATERIALS: Four patients with mandibular alveolar ridge atrophy were evaluated. Three-dimensional computed tomography reconstructions were obtained 2 weeks before and 3 months after the operation. The results of the three-dimensional computed tomography measurements were used for preoperative planning and for quantitative assessment of the mandibular alveolar distraction. The results of the preoperative and postoperative three-dimensional computed tomography measurements were compared statistically using paired t-test. RESULTS: The increase in distracted mandibular segment volume and surface area, height, and width of each slice after distraction were statistically significant (P < 0.001). CONCLUSION: In atrophic jaw cases, the dimensions of the present alveolar bone were clearly measured so that the amount of augmentation needed could be estimated. Three-dimensional computed tomography provided better understanding of the effects of distraction osteogenesis on the anterior mandible. Newly formed bone can be viewed as close to its real dimensions after distraction osteogenesis.     

Use of alveolar distraction osteogenesis for implant placement: a case report with eight‐year follow‐up

Insufficient alveolar ridge width may impede the success of dental implants. Techniques for resolving this problem include autologous bone grafts, guided bone regeneration, bone splitting and bone spreading techniques. Recently, alveolar distraction osteogenesis has become an alternative method for alveolar augmentation. We propose the use of alveolar bone distraction for insufficient alveolar ridge width. A healthy 33‐year‐old female presented with missing teeth to our clinic. Clinical and radiographic examination revealed the alveolar ridge was too narrow for placement of dental implants. Therefore, horizontal distraction osteogenesis of the posterior mandibular ridge was chosen for augmentation. Two months later, two implants were placed. No significant marginal bone resorption was seen around the implants eight years after placement. Our results indicate that horizontal alveolar distraction is recommended to increase ridge width and allow placement of standard dental implants.     

Distraction osteogenesis versus autogenous onlay grafting. Part I: outcome of implant integration

PURPOSE: The primary goal of this study was to compare bone-to-implant contact (BIC) in alveolar bone augmented by distraction osteogenesis with BIC in alveolar bone augmented by onlay iliac crest grafting. MATERIALS AND METHODS: Alveolar bone defects were created bilaterally in 5 American foxhounds, and after healing, bone augmentation was accomplished using distraction osteogenesis on 1 side of the jaw and onlay grafting on the other. Twelve weeks after consolidation, implants were placed in augmented and control sites. The animals were sacrificed and the jaws harvested for histologic analysis after an additional 8 weeks. RESULTS: The mean BIC was 54.7% +/- 14.6% for implants placed in distracted sites, 53.8% +/- 11.8% for sites where an onlay graft was used, and 51.2% +/- 14.4% for control sites. Significant differences in BIC were noted between experimental and control sites only at the apical third of the implant (19.8 +/- 1.8 for distracted sites; 15.5 +/- 1.5 for grafted sites; 8.0 +/- 0.5 for control sites; P < .05). DISCUSSION: The data showed that both distraction osteogenesis and onlay grafting produce sufficient bone for implant placement. There were no differences between procedures in regard to BIC after 8 weeks. CONCLUSION: These data suggest that both onlay grafting and vertical distraction are appropriate methods for bone augmentation prior to implant placement.     

3D vector control during alveolar ridge augmentation using distraction osteogenesis and temporary anchorage devices: a new technique

This report describes a combined orthodontic surgical technique involving vertical alveolar distraction using temporary anchorage devices (TADs) in cases of massive alveolar ridge bone and teeth loss. A combined surgical orthodontic protocol included presurgical orthodontic preparation and a preimplantation surgical augmentation stage for insertion of a vertical distractor. During the active vertical alveolar distraction process TADs were inserted. Intraoral orthodontic elastics were attached to the main orthodontic archwire exerting multidirectional forces to control the vertical distraction vector. After 3 months of vector controlling and active bone moulding, the TADs were removed. Anterior alveolar ridge augmentation using distraction osteogenesis was achieved. The application of TADs for better anterior segment curvature enabled dental implant insertion, better positioning and restoration. A combined surgical orthodontic management protocol involving vertical alveolar distraction osteogenesis for augmentation purposes is an efficient treatment method to improve alveolar ridge volume for the preimplantation stage.     

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.     

Horizontal alveolar ridge distraction osteogenesis in dogs: radiographic and histologic studies

PURPOSE: This study was designed to evaluate the healing process in horizontal alveolar ridge distraction of the narrow alveolus in dogs. MATERIALS AND METHODS: Six beagle dogs weighing approximately 9 to 10 kg were used in this experiment. Horizontal alveolar ridge distraction was performed in the right mandible, where the premolars had been extracted 12 weeks previously. Twelve days after the completion of distraction, the lengthening apparatus was removed. The distracted site was evaluated at 12 and 24 weeks after the removal. RESULTS: At 12 weeks, thin woven bone was observed at the distracted site growing from the surface of the original lingual cortical bone toward the transport segment. At 24 weeks, the distracted site had fully changed into new mature lamellar bone, but the transport segments had been almost completely resorbed. DISCUSSION: Horizontal alveolar ridge distraction was performed successfully in beagle dogs even though the apparatus was removed 12 days after the completion of distraction. The most important feature of this technique is the resorption of the transport segment. CONCLUSION: Horizontal alveolar ridge distraction can be a beneficial technique for augmenting the alveolar ridge horizontally in the buccolingually reduced alveolar process before the placement of implants.     

Bone resorption and complications in alveolar distraction osteogenesis

Distraction osteogenesis presents an alternative procedure for augmentation of atrophic alveolar bone prior to inserting dental implants. The aim of this retrospective study was to evaluate complications of this method with specific focus on bone resorption during the consolidation period and the follow-up period after dental implant insertion into distracted bone. Thirty partially edentulous patients underwent a total of 36 vertical alveolar distractions with an extraosseous distraction system. Eleven devices were placed in the maxilla and 25 in the mandible. Eighty-two dental implants were inserted after a mean consolidation period of 4.5 months. Treatment results were evaluated by means of panoramic radiographs for distraction follow-up and periapical radiographs for implant follow-up. The mean length of the transport segment was 19 mm. The average alveolar height achieved was 6.4 mm with a mean resorption of 1.8 mm (21.1%) at the time of dental implant insertion. Main problems comprised oral displacement of the transport segment (n = 15) and inadequate soft tissue extension (n = 13). Eighty-two dental implants were inserted with an overall survival rate of 95.1% after 45.8 months. For periimplant marginal bone, an average resorption of 3.5 mm was recorded 50.4 months after implant insertion. Although alveolar distraction osteogenesis seems to be an effective tool to treat vertical defects of the alveolar ridge, it is not an uncomplicated procedure. A combination with vestibular augmentation of autogenous bone grafts should be considered. Overcorrection of 20% may compensate bone relapse during the consolidation period of the distracted alveolar bone. Further bone resorption after dental implantation is common.