小型猪骨膜成骨修复下颌骨节段性缺损的研究

目的:探讨原位骨膜成骨修复小型猪下颌骨节段性缺损的可行性。方法:选用13个月龄小型猪8只,雌雄不限,拔除右侧下颌前后磨牙3个月后,随机分为保留骨膜组(A组)和不保留骨膜组(B组),每组4只。再按骨缺损长度分为30 mm组和40 mm组,每组各2只。制备小型猪下颌骨体部30 mm和40 mm节段性骨缺损,利用钛板固定两侧骨断端,A组完整保留缺损区颊舌侧的骨膜并将其严密缝合形成一封套层,B组则不保留骨膜,术后4、8、12周进行影像学观察。结果:影像学观察保留骨膜组术后12周完成骨连接,新生骨形态规则,不保留骨膜组未完成骨连接,仅在骨断端有极少量新生骨,且形态不规则。结论:利用骨膜原位成骨可以修复下颌骨较大范围节段性骨缺损。     

自发成骨修复小型猪下颌骨缺损的组织病理学研究

目的研究保留和去除骨膜情况下自发成骨修复小型猪下颌骨节段性缺损的组织学表现。方法选择18月龄雌性中国小型猪8只,拔除其右侧下颌前磨牙及第一磨牙,2个月后动物随机分为保留骨膜组（A组）与去除骨膜组（B组）。A组骨块切除长度分别为5cm与6cm,B组骨块切除长度分别为1cm与2cm,每个长度对应2只动物,骨块切除后均行坚固内固定。术后12周处死动物,标本行大体、x线及HE染色后组织学观察。结果保留骨膜5cm与去除骨膜1cm组完成骨连接,保留骨膜6cm与去除骨膜2cm组未完成骨连接。保留骨膜组可见膜内成骨,去除骨膜组可见软骨内成骨。两组未完成骨连接处可见纤维组织或纤维软骨组织。结论保留骨膜的成骨作用优于去除骨膜;保留骨膜时可以自行修复较大长度的骨缺损。     

骨膜原位成骨促进兔下颌骨缺损修复的研究

目的动态观察并验证骨膜在骨缺损修复过程中的作用。方法12只6个月龄新西兰大白兔随机分为去除骨膜组和保留骨膜组,每组6只,均制备下颌骨体10mm×8mm全层骨缺损,术后2周、4周、8周每组处死2只动物,标本行肉眼、X线、扫描电镜及组织学观察,计算缺损区新骨面积,两组间行独立样本t检验。结果X线、扫描电镜及组织学结果显示,第4、8周时保留骨膜组的成骨速度、新骨量及骨密度均优于去除骨膜组,第2周时两组间差异不明显。保留骨膜组后期出现少量中央成骨,去除骨膜组整个观察期间主要为边缘成骨。第2周时两组间新骨生成面积无明显差异,第4、8周时差异有统计学意义。结论保留骨膜能促进成骨,手术1个月后骨膜成骨的效果更明显。     

下颌骨切除骨缺损修复术后的X线影像分析

目的 :观察下颌骨切除骨缺损修复术后X线影像特点。方法 :对下颌骨良性肿瘤切除骨缺损修复术后的42例病例的X线影像分析。结果 :骨性愈合 31例 ;植入骨吸收 5例 ;植入块断裂 6例。结论 :曲面断层和下颌骨侧位应作为术后必备的片位 ;术后 1～ 2周、3～ 6月、1年以后作为随访的三个阶段 ,能较准确地观察术后愈合情况     

骨膜、骨髓单个核细胞复合纳米羟基磷灰石修复骨缺损的实验研究

目的:将骨膜、骨髓单个核细胞(BM-MNCs)、纳米羟基磷灰石(纳米-HA)复合应用于引导性骨再生,为临床修复骨缺损探索一条有效的途径。方法:6-8月龄实验用白兔18只,在兔双侧下颌骨各制备一10 mm×8 mm,深5 mm的骨缺损,按随机数字表法分为3组,每组6只,即A组用自体游离骨膜、骨髓单个核细胞和纳米羟基磷灰石复合修复,B组用自体游离骨膜和纳米羟基磷灰石修复,C组单纯用纳米羟基磷灰石充填修复。分别于术后第4、8、12周末用空气栓塞法处死动物,每次每组处死2只,标本行肉眼、X线、扫描电镜及组织学观察,计算缺损区新骨面积。结果:实验组A组在术后4、8、12周的骨密度值均高于其他两组(P<0.05)。环境扫描电镜观察显示,A组新生骨和原有骨结合致密且骨结构相似。组织学观察表明,A组材料大部分降解,大量成熟骨形成,较少材料包裹于其中,各项指标均优于其他组。结论:骨膜、骨髓单个核细胞、纳米羟基磷灰石复合的成骨作用优秀,可有效促进骨缺损愈合。     

下颌骨缺损即刻修复的动物实验研究

目的:通过动物实验,观察较大下颌骨缺损及伴牙脱位的下颌骨缺损后骨复合材料结合生物膜即刻修复的效果.方法:40只健康新西兰大白兔,随机分为3组.A组为下颌骨缺损后未植入骨复合材料,B组为植入骨复合材料加Bio-gide膜,C组为植入骨复合材料加Bio-gide膜,同时在其上植入自体脱位牙.分别于术后4、8及12周处死动物,获取标本行大体观察、X线检查及组织学观察.结果:术后12周,A组下颌骨缺损处形成一较原截骨范围略小的骨缺损;B组下颌骨缺损区基本由新生骨组成,X线观察骨缺损区密度接近正常骨组织,组织学观察骨植入物基本形成板状骨;C组动物自体再植牙有17例无明显松动,X线观察13例根尖无透射区,组织学观察有13例出现替代性吸收.结论:骨复合材料结合生物膜即刻修复较大下颌骨缺损效果良好,在其上进行自体牙再植,近期效果较好.     

在移植骨上延期种植的实验研究

目的论证冷冻自体下颌骨复合髂骨移植后延期种植的可行性。方法16只成年雄性杂种狗，制备下颌骨双侧骨缺损，左侧行冷冻自体下颌骨骨块的原位再植并结合髂骨松质骨移植，即复合移植组（composite transplantation group，CTG），右侧缺损行自体髂骨块移植即髂骨移植组（iliac transplantation group，ITG），术后3个月分别在两类骨块上植入IMZ TPS种植体，种植体植入后3、6、9、12周分别处死4只动物取材，采用数字化X线片对种植体与颌骨结合界面进行灰度定量分析，组织学观察种植体．骨结合情况。结果各期种植体周围均未见吸收性骨质密度减低影像。骨一种植体界面灰度定量分析显示，种植体植入两类移植骨3、6和9周时，其界面骨质密度改变差别明显，复合移植组明显优于髂骨移植组；种植体植入12周时，两组界面骨质已无明显差别，两类移植骨均与种植体有良好的骨结合，其骨愈合方式基本相同。结论冷冻自体下颌骨复合移植修复下颌骨缺损并延期植入牙种植体后，二者可形成良好的骨结合。     

无机诱导因子支架材料行颌骨重建的放射学评价

目的:在实验外科的基础上,用预制型无机诱导因子复合性支架材料对颌骨缺损行修复重建,从放射学角度评价组织工程化骨构建的效果。方法:实验组对15只山羊下颌角缺损(30mm×25mm×10mm大小)以预制型支架材料修复,左侧为实验组,右侧为空白对照组,术后分别于4、8、12周处死5只动物行X线检查。临床应用组31例,分别于术后5d、1、2、3、6个月摄取下颌骨全景片和CT,观察骨缺损区的新骨形成情况,并按X线分级评分、6点法和X线阻射密度测量的评分标准测评,对各组的X线评分值及阻射密度值进行t检验。结果:实验组骨缺损放射影像评分及新生骨情况在4、8、12周显著优于对照组,空白对照组12周时骨缺损区均无明显骨修复现象。临床应用组发现组织工程骨表现出随时间的增长,成骨量逐渐增加的特征,在6个月时,阻射静止期有骨髓重建X线像。结论:预制型无机诱导因子复合性支架材料具有优良的成骨效果,放射学检查对骨缺损的评估有重要意义。     

骨髓基质细胞复合多孔矿化Bio-Oss骨胶原移植修复下颌骨缺损的实验研究

目的:探讨以多孔矿化Bio- Oss骨胶原为载体的自体骨髓基质细胞移植修复下颌骨缺损的效果。方法:标准成年新西兰白兔16只随机分2组,一组抽取骨髓基质细胞进行培养,矿化诱导后,细胞悬液与凝胶混匀滴入Bio- Oss胶原骨块中, 静置于37℃, 50ml/L的CO2 培养箱中温育4 ~6h,加入DMEM成骨条件培养液培养。然后修复下颌骨极限骨缺损。另组单纯Bio -Oss胶原块,修复下颌骨极限骨缺损。分别于术后8周和12周取材,分别行大体、X射线、组织学观察骨缺损的修复情况。结果:术后12周, (1)BMSC 凝胶 Bio -Oss胶原组,基本上由新生骨组织所修复。(2)单纯Bio- Oss胶原组大部分由纤维组织填充,周围骨形成明显,中央少量骨痂形成。结论: (1)Bio -Oss骨胶原有较强的诱导成骨能力; ( 2 )Bio -Oss骨胶原为载体的自体骨髓基质细胞移植能有效修复骨缺损,是骨组织工程良好的支架材料。     

骨膜及下齿槽血管束对下颌骨牵张延长的作用

目的:确定下颌骨较差血运状态下进行牵张延长术的参数。方法:成年家兔16只,体质量2. 4~2. 6kg,随机等分为4组,每组4只;行双侧下颌骨骨切开术,采用内置式牵张器(西安中邦公司研制)对双侧下颌骨同时进行牵引;手术时破坏左侧下颌骨膜及下齿槽血管,而保护右侧。延迟期分别为1、7d;牵引速率分别为0. 5、1. 0mm/d, 2次/d;牵引距离均为10mm;保持期为4周。拍摄X线片,测量新骨抗弯强度,并脱钙组织切片观察。结果:骨膜及下齿槽血管破坏侧,延迟期7d组,牵张区新骨形成良好;延迟期1d组成骨质量较差或导致骨不连。结论:兔下颌骨骨膜及下齿槽血管破坏之后,也能进行牵张成骨修复,但要适当延长延迟期,对临床上早期应用牵张成骨技术修复创伤性下颌骨缺损有一定提示作用。     

bFGF复合NNB无机骨修复兔下颌骨缺损的实验研究

目的研究碱性成纤维细胞生长因子(bFGF)与天然型无机骨(NNB)复合人工骨修复兔下颌骨缺损的效果,以期为临床提供一种较为理想的骨替代材料.方法在30只成年新西兰兔双侧下颌骨下缘形成15mm×6mm全层骨膜骨质缺损,每一缺损作为一个实验单位,术后3周、6周、12周取材行大体标本、X片观察,并对HE染色切片行计算机定量分析.结果复合骨与NNB相比,同期成骨量大;6周时复合骨成骨面积尚不如自体骨,而12周时已接近自体骨水平,空白缺损则始终未能修复.结论复合骨生物相容性好,效果明显优于NNB,远期与自体骨相似,是一种较为理想的骨替代材料.     

Quantitative computed tomography bone mineral density measurements in irradiated and non-irradiated minipig alveolar bone: an experimental study

Objective: The objective of this study was to analyse the effect of irradiation on bone mineral density (BMD). Materials and methods: All maxillary and mandibular pre‐molars and molars of six minipigs were extracted. After a 3‐month healing period, the maxilla and mandibles of three minipigs received three irradiation exposures at a total dose of 24 Gy. At 3 months after irradiation, quantitative computed tomography (QCT) was performed. As a reference, a calibration bone phantom with pre‐determined BMD was attached to the head of the minipigs. The QCT data were imported into a software program to calculate the BMD of the alveolar bone and the calibration bone phantom. In order to compare BMD values of individual minipigs, the so‐called bone mineral density quotient (BMDQ) was created, dividing the BMD value of the alveolar bone by the BMD value of the calibration bone phantom. Results: Mean BMDQ values appeared to be higher in irradiated than in non‐irradiated minipigs. However, the difference was not significant. In both irradiated and non‐irradiated minipigs, the average mandibular BMDQ values were statistically significantly higher than the average maxillary BMDQ values (P=0.003). The P‐values of the Student t‐test, determining the irradiation effect, were 0.11 for maxillary, 0.14 for mandibular, and 0.07 for overall peri‐implant BMDQ. P‐values of the non‐parametric Mann–Whitney test were all 0.05. Conclusion: It could be concluded that, 3 months after irradiation, the BMD of irradiated alveolar minipig bone was increased, when compared with non‐irradiated alveolar minipig bone. However, the increase was not statistically significant.     

Effects of fibrin sealant protein concentrate with and without platelet-released growth factors on bony healing of cortical mandibular defects. An experimental study in minipigs

In this study, the effects of fibrin sealant protein concentrate (FSPC; from the Tissucol Kit, Baxter, Vienna, Austria) with and without platelet-released growth factors (PRGF) on bony healing of cortical mandibular defects were investigated. Defects made in the facial mandibular wall of eight adult minipigs with a hollow drill were filled with FSPC alone, a mix of FSPC+PRGF or left untreated as controls. The animals were killed 4 and 8 weeks later. Specimens were processed for histology with the Donath method (1988) and stained with the Levai-Laczko stain. On histology, periosteal osteoneogenesis exceeded endosteal bone formation. No difference was seen in bone formation between FSPC alone, FSPC+PRGF and the controls at 4 and 8 weeks. On histomorphometry, there was no significant difference between the three groups in terms of the percent of newly formed bone at 4 and 8 weeks (P=0.6977). This study showed that FSPC neither increased nor decreased the amount of newly formed bone vs. controls and that the addition of PRGF had no effects on bone regeneration of cortical minipig bone at 4 and 8 weeks.     

Prototyped grafting plate for reconstruction of mandibular defects

To esthetically and functionally restore a 40-mm canine mandibular discontinuity defect using a custom-made titanium bone-grafting plate in combination with autologous iliac bone grafts. Individualized titanium bone-grafting plates were manufactured using a series of techniques, including reverse engineering, computer aided design, rapid prototyping and titanium casting. A 40-mm discontinuous defect in the right mandibular body was created in 9 hybrid dogs. The defect was restored immediately using the customized plate in combination with autologous cancellous iliac blocks. Sequential radionuclide bone imaging was performed to evaluate the bone metabolism and reconstitution of the grafts. The specimens were evaluated by biomechanical testing, 3-dimensional microcomputed tomographic scanning, and histological examination. The results revealed that the symmetry of the mandibles was reconstructed using the customized grafting plate, and the bony continuity of the mandibles was restored. By 12 weeks after the operation, the cancellous iliac grafts became a hard bone block, which was of comparable strength to native mandibles. A fibrous tissue intermediate was found between the remodelled bone graft and the titanium plate. The results indicate that the prototyped grafting plate can be used to restore mandibular discontinuous defects, and satisfactory aesthetical and functional reconstruction can be achieved.     

Assessment of vascularity in irradiated and nonirradiated maxillary and mandibular minipig alveolar bone using laser doppler flowmetry

PURPOSE: The purpose of this animal study was to confirm that laser Doppler flowmetry (LDF) is a reproducible method for the assessment of maxillary and mandibular alveolar bone vascularity and that there is less vascularity in irradiated mandibular and maxillary bone compared to nonirradiated bone. MATERIALS AND METHODS: All maxillary and mandibular premolars and molars of 6 G?ttingen minipigs were extracted. After a 3-month healing period, 3 minipigs received irradiation at a total dose of 24 Gy. Three months after irradiation, 5 holes were drilled in the residual alveolar ridge of each edentulous site in each minipig. Local microvascular blood flow around all 120 holes was recorded by LDF prior to implant placement. In 1 irradiated and 1 nonirradiated minipig, an additional hole was drilled in a right maxillary site to enable repeated LDF recordings. RESULTS: The alveolar bone appeared less vascularized in irradiated than in nonirradiated minipigs. The effect of radiation appeared more pronounced in the mandible than in the maxilla. LDF was demonstrated to be a reproducible method for assessing alveolar bone vascularity. However, recordings varied by edentulous site as well as by minipig. CONCLUSION: The authors' hypotheses regarding LDF and vascularity were supported. Further research validating the use of LDF in human beings, especially in those who have undergone radiation therapy for head and neck cancer, is necessary.     

hBMP-7基因修饰犬骨髓基质干细胞复合珊瑚羟基磷灰石修复下颌骨缺损

目的:构建携带人骨形态发生蛋白7(hBMP-7)基因的重组腺病毒载体,体外转染犬骨髓基质干细胞(dMSCs)复合珊瑚羟基磷灰石(coral hydroxyapatite, CHA),观察其修复下颌骨缺损的效果。方法:利用AdEasy腺病毒表达系统,体外构建高效表达hBMP-7重组腺病毒载体,转染dMSCs 与珊瑚羟基磷灰石支架材料复合,再分别植入取材动物的自体下颌骨缺损区,分别于4周和8周取材观察成骨情况。结果:大体观察、X线检查及组织学观察均发现构建组织工程骨在祼鼠皮下及骨缺损处均有明显新骨组织形成。结论:构建携带人骨形态发生蛋白7(hBMP-7)基因的重组腺病毒载体,体外转染dMSCs后复合珊瑚羟基磷灰石有较多量骨组织形成,可有效修复下颌骨缺损。[关键词] 人骨形态发生蛋白7 骨髓基质干细胞 腺病毒 组织工程     

冷冻异体骨膜引导骨组织再生的实验研究

目的：探讨用冷冻异体骨膜作为引导骨组织再生膜的可能性；方法：取兔颅骨顶部骨膜经冷冻处理，在３１只日本大耳白兔的下颌骨造成两处骨缺失，采取同体对照，一处表面覆盖冷冻异体骨膜，另一处不覆盖。分别在第４、８、１２、１６周处死动物，行Ｘ线及组织学观察。结果：冷冻异体骨膜不产生排斥反应，可在体内维持８￣１２周，具有良好的阻挡纤维组织长入骨创面、分隔不同细胞及引导组织再生的功效。结论：冷冻异体骨膜是一种理想的