骨髓基质细胞诱导分化修复髁突软骨面缺失的实验研究

目的:采用骨髓基质细胞(BMSCs)体内修复髁突软骨全层缺失。方法:15只山羊,9只作为实验组,将BMSCs和少量软骨细胞(7:3比例混合)按5×107/mL与生物可降解材料复合后,植入山羊髁突软骨全层缺失处;对照组6只山羊,髁突软骨全层缺失区植入支架材料,分别于术后4、8、12周每个时间段取材3只实验动物,2只对照组动物;2组分别用HE染色、Ⅱ型胶原分泌的免疫组化法进行评价。结果:实验组术后4周,山羊髁突软骨缺失区能形成成熟的软骨组织,12周时软骨未退变。对照组不能形成成熟的软骨组织。结论:骨髓基质细胞在自体软骨细胞基质的诱导下,可以修复山羊颞下颌关节髁突软骨面全层缺失。     

输送盘牵张成骨术重建下颌髁突后对下颌骨生长发育的影响

目的:研究输送盘牵张成骨术重建下颌髁突后对下颌骨生长发育的影响.方法:选用3～4 月龄健康幼年雄性山羊16 只,手术切除右侧髁突(保留关节盘),在右下颌升支行反"L"形骨切开术形成骨输送盘,并安置牵张器.以每日2 次,每次0.4 mm的速率向上牵引输送盘至关节窝.在手术后当天、牵张结束后当天、牵张结束后4、12、24、48 周时行三维CT检查评价输送盘改建及牵张间隙内新骨形成情况,并分别于12、24、48 周3 个时间点各处死动物2 只对新生髁突做组织学检查.牵张结束后48 周时处死剩余10 只动物,对下颌骨及重建髁突形态进行观察与测量.左侧下颌骨作为正常对照组.结果:三维CT显示新生髁突形态逐渐改建并接近正常髁突,牵张间隙新骨生成良好.大体观察发现新生髁突体积较正常侧明显增大,但下颌骨的生长与正常侧无显著差异.新生髁突表面有一层纤维软骨覆盖,组织学结构与正常关节软骨类似.结论:输送盘牵张成骨重建髁突未对下颌骨的生长发育产生明显影响;下颌运动产生的功能刺激是下颌骨继续生长发育的主要原因.     

牵引成骨重建缺损山羊下颌骨髁突的实验研究

目的：通过建立山羊牵引成骨延长下颌支重建下颌支高度动物模型,对山羊下颌支牵引成骨区新骨的组织及组织形态学进行观察,为牵引成骨术在下颌支缺损区的临床应用提供理论依据。方法：12只山羊随机分为4组,每组3只。实验用山羊在下颌切迹下方截骨,切除一侧髁突及其颈部,左右随机。再于下颌支后缘形成转移盘。牵引延长下颌支,于牵引结束后2、4、8、12周分别进行大体、组织学及组织形态学观察,并用Axioplan2imaging显微图像分析系统进行处理,结果采用SPSS12.0软件包进行t检验。结果：从牵引结束后4周始,通过牵引成骨形成的新髁突已经具备与正常山羊髁突相似的外形;组织学及组织形态学结果显示,牵引区新骨随时间推移,钙化程度增加。至牵引结束后6周时,牵引区新骨矿化率为（1.35±0.57）μm/d,已经接近正常山羊下颌支矿化率（0.95±0.13）μm/d（P〉0.05）。结论：以山羊作为下颌支及髁突缺损牵引成骨重建动物模型具有较好的重复性,与临床情况具有相似性。牵引结束后6周,可以考虑拆除牵引器,以利新骨在生理状态下进行功能改建。     

BMSCs／PLGA复合物修复山羊下颌髁突骨软骨缺损的实验研究

目的：观察利用BMSCs／PLGA复合物修复山羊下颌髁突骨软骨缺损的可行性及效果。方法：选取36只成年健康山羊，一侧关节制备3mm直径、5mm深的髁突表面骨软骨缺损，根据植入物不同分为BMSCs／PLGA复合物组、PLGA组及空白组，另一侧关节作为正常对照组。分别在术后6周和24周后处死每组6只动物，标本进行大体及组织学检查比较。结果：术后24周时空白组下颌髁突骨软骨缺损未能自发修复；植入PI。GA组的缺损表面虽有软骨形成，但连续性有中断；植入BMSCs／PLGA组的修复效果最佳，表面软骨接近正常纤维软骨。组织学评分结果也显示BMscs／PLGA组明显优于材料组和空白组。结论：BMSCs／PLGA复合物可以作为一种修复下颌髁突骨软骨缺损的新的有效方法。     

生长期山羊囊内骨折复位术中保留髁突软骨的重要性及组织学研究

目的：通过组织学观察,探讨髁突囊内骨折内固定术中保留和切除髁突软骨对髁突生长发育的影响。方法：6个月龄山羊12只,随机分为实验组（n=8）和对照组（n=4）。实验组双侧髁突造成囊内骨折并同期行手术复位固定．一侧保留髁突软骨,另一侧切除髁突软骨。术后3个月、6个月处死动物,切取髁突标本行石蜡切片和硬组织切片观察骨折愈合和髁突生长情况。结果：实验组髁突骨折愈合良好,钛板被新生骨组织覆盖;HE染色显示．保留髁突软骨组,髁突软骨结构清晰,与正常对照髁突相同,软骨成骨活跃,髁突生长发育正常;切除髁突软骨组,髁突软骨层消失,表面为成熟的骨细胞覆盖,直接与关节盘的纤维组织相连,新生骨组织少见：硬组织切片显示,钛板与骨组织直接结合．未见组织渗出和排异反应。结论：手术复位髁突囊内骨折时保留髁突软骨,不会影响髁突的生长发育;损伤髁突软骨．会造成髁突与关节盘黏连．引起髁突生长发育障碍。     

不同方法诱导的骨髓基质细胞用于修复山羊髁突软骨缺失的实验研究

目的:比较用诱导因子诱导及用部分成体软骨细胞诱导的骨髓基质细胞(BMSCs)复合生物材料修复山羊颞下颌关节髁突软骨全层缺失的效果.方法:取山羊6只,分为2个实验组及1个对照组,每组2只.实验Ⅰ组植入经诱导因子(TGF-131、IGF-1、地塞米松)诱导的BMSCs与支架(PIuronic F-127溶胶)复合物,实验Ⅱ组植入软骨细胞-BMSCs(按3:7比例混合)的细胞-支架复合物,对照组仅植入支架材料.于术后8周取材,进行颞下颌关节软骨面缺失修复的大体观察、修复组织的HE染色、Ⅱ型胶原分泌的免疫组化染色.结果:术后8周实验Ⅱ组髁突软骨缺失区由软骨样组织修复.HE染色及免疫组化染色结果均提示修复组织为成熟的软骨组织.而实验Ⅰ组及材料对照组缺损区仅由少量的纤维性组织修复,不能形成成熟的软骨组织.结论:骨髓基质细胞在自体软骨细胞基质的诱导下,可以修复山羊髁突软骨面全层缺失,二维培养诱导后的BMSCs在山羊髁突软骨缺失区难以达到修复作用.     

山羊髁突刨削术后髁突软骨面修复的初步观察

目的:观察山羊髁突刨削术后髁突的愈合过程。方法:实验动物7只山羊,将6只山羊两侧髁突软骨面磨除,另1只未做手术为正常对照。分别于术后4、8、12周;每个时间点取材2只实验动物进行HE染色加以评价。结果:术后4周山羊髁突软骨缺失区粗糙,为骨样及一些纤维样组织修复,或可见少许纤维样软骨;术后8周及12周髁突表面较术后4周时光滑,修复组织逐渐变为以骨性组织为主,软骨样成分逐渐消失。结论:经过关节髁突的刨削术,术后3个月时,实验动物髁突软骨缺失区不能形成正常的软骨组织。     

胶原复合梯度磷酸三钙修复髁突软骨缺损

目的 研究胶原复合梯度磷酸三钙(Col/TCP)修复髁突软骨损伤的效果.方法 选用成年雄性新西兰大白兔30只,在实验动物的右侧髁突前斜面形成3 mm × 4 mm的全层缺损后,植入复合材料;左侧仅造成同样的缺损.分别于术后4、6、8、12和24周各处死6只实验动物,对缺损区的新生软骨进行大体标本、组织学、免疫组织化学及透射电镜观察.结果 实验组4周后复合材料即可诱导关节软骨的修复;12周时缺损区与周围正常软骨基本一致,且与关节下骨结合紧密;24周后再生软骨未见明显褪变;对照组缺损区由纤维组织充填,未见软骨形成.实验组Ⅱ型胶原免疫组织化学染色呈阳性,对照组为阴性;透射电镜观察实验组见典型软骨细胞出现,对照组为纤维组织.结论 Col/TCP可以修复髁突软骨缺损,形成类似正常的关节软骨.     

人髁突骨髓间充质干细胞体内成骨的实验研究

目的 探讨人髁突来源骨髓间充质干细胞(bone marrow-derived mesenchymal stem cells,BMSC)体内分化成骨的能力,为构建组织工程髁突提供种子细胞.方法取切除的人髁突冲洗收集骨髓细胞,采用密度梯度离心和贴壁培养法进行培养和纯化BMSC,取第3或4代BMSC进行成骨细胞和成软骨细胞诱导分化后接种于珊瑚骨支架表面,扫描电镜观察细胞在支架表面的黏附和增殖状况.将成骨或成软骨细胞-珊瑚骨支架植入裸鼠背部皮下,6和9周后观察体内成骨和成软骨情况.结果 培养3～7d后扫描电镜显示细胞黏附于珊瑚骨支架表面,呈多层生长,并跨越微孔连成网状或片状;植入裸鼠体内9周,髁突形珊瑚骨支架均基本维持最初的形态,可见散在或片状的新生骨形成,新生软骨呈岛状分布.结论从人髁突骨髓中分离出的BMSC具有体内形成新骨和软骨组织的能力,可作为构建组织工程髁突的种子细胞.     

醋酸泼尼松龙对髁突软骨急性损伤后修复的影响

目的　研究局部应用糖皮质激素类药物对髁突软骨损伤后修复再生的影响。　方法选用成年雄性大白兔 37只 ,分成 4组。第 1组 :髁突软骨全层损伤后局部应用醋酸泼尼松龙组 ;在兔髁突的前斜面形成直径 2mm的软骨全层缺损 ,局部应用醋酸泼尼松龙 2 5mg。第 2组 :单纯髁突软骨全层损伤组。第 3组 :空白手术对照组。第 4组 :正常对照组。结果　第 1组动物的髁突软骨损伤区骨皮质断端进行性增生 ,术后 12周时 ,原损伤区几乎充满致密骨质 ,表面有纤维组织覆盖。结论　醋酸泼尼松龙可促进髁突软骨损伤后的组织修复     

Microscopic changes in the condyle and disc in response to distraction osteogenesis of the minipig mandible.

PURPOSE: Unilateral mandibular distraction osteogenesis (DO) has been shown to cause gross changes in the mandibular condyle and articular disc. The purpose of this study was to correlate histologic findings with these gross changes in a minipig distraction model. MATERIALS AND METHODS: Semiburied distractors were placed via submandibular incisions in 15 minipigs. Two unoperated animals served as controls. The protocol consisted of 0-day latency and rates of 1, 2, or 4 mm/day for a 12-mm gap. After the minipigs were killed (at 0, 24, or 90 days), ipsilateral and contralateral condyles and discs were harvested, decalcified, prepared for standard paraffin embedding, and evaluated to determine changes in 1) morphology and thickness of the articular cartilage and subchondral bone and 2) morphology of the disc. RESULTS: In control animals, there were no degenerative changes in the articular cartilage and underlying condylar bone; there were no significant differences in the mean articular cartilage thickness. The temporomandibular joint discs were normal. In experimental animals, distracted condyles showed increasing degenerative changes and mean articular cartilage thickness as the DO rate increased. The discs were thinner. These changes were present, but to a lesser degree, in the contralateral condyles. After 90 days, degenerative changes in the condyles and discs were reduced, after remodeling, except in the 4 mm/day DO group. CONCLUSIONS: Histologic changes in the condyles and temporomandibular joint discs in response to mandibular DO correlated with previously reported gross changes. These changes were greater at higher distraction rates and remodeling back to normal occurred in mandibular condyles distracted at 1 mm/day.     

Histological evaluation of condylar hyperplasia model of rabbit following distraction osteogenesis of the condylar neck

Summary Condylar hyperplasia is the excessive unilateral growth of mandibular leading to facial asymmetry, occlusal disturbance, joint pain and dysfunction. The aim of this study is to evaluate the histological presence of temporomandibular joint in model of condylar hyperplasia by lengthening unilateral condylar neck of distraction osteogenesis. An extra oral distractor was employed to achieve unilateral condylar neck distraction (1·0 mm daily for 7 days). The experimental condylar necks were elongated by 7 mm compared to the contralateral. Eleven adult white rabbits were used. Eight rabbits were, respectively, sacrificed after the post‐distraction period (4 or 8 weeks). All animals were evaluated clinically and histomorphometrically. The condyles radiologically showed remodelling, flattening and sclerosis. In 4‐week group, thinning of the cartilage was evident, and the trabeculae were long, not multiply connected. A thin, dense fibrous layer covered all over the surface of cartilage. In 8‐week group, the cartilaginous layer was similar to thickness of the normal cartilage, but still thinner than control. However, the fibrous layers covering condyle manifested slight degenerative changes, and even depressions and erosions were seen in the cartilage and subchondral bone. The trabeculae showed denser and multiply connected. In 8‐week group, the cartilaginous thickness of surgical condyles was significantly thinner than the contralateral. This study indicates that unilateral distraction of condylar neck loads the condyles asymmetrically. Asymmetrical loads affect more on the surgical condyles than the contralateral, and after 8 weeks of the post‐distraction, condyle could recover from asymmetrical loads in some degree.     

运用输送盘牵张成骨术重建猴下颌髁突的实验研究

目的研究在猴颞下颌关节（TMJ）缺损动物模型上运用输送盘牵张成骨术重建髁突的可行性及其整复效果。方法选取6只成年恒河猴,手术截除其双侧关节髁突与关节盘,在下颌升支部行“L”形骨切开术,形成骨输送盘,并安置自行研制的牵张器。按每次0.4 mm,每次间隔12 h的牵张速率向上牵引输送盘至关节窝。牵张结束后第4、12、24周各处死2只动物。通过影像学分析和组织学检查评价输送盘改建与牵张间隙内新骨生成情况。以术中切除的髁突作为正常对照组。结果术后所有动物都有不同程度的咬合错乱,牵张结束后咬合基本恢复正常。骨输送盘形态基本接近正常髁突,其下方可见大量软骨细胞;牵张间隙内新骨生成良好。结论输送盘牵张成骨术可以重建一个形态和功能都基本接近正常的髁突,这种技术可以作为一种整复TMJ缺损的新方法。     

牵张成骨延长一侧下颌骨对颞下颌关节的影响

目的：研究牵张成骨（DO）延长一侧下颌骨对双侧颞下颌关节（TMJ）的影响。方法：用DO技术将8只山羊的一侧下颌骨延长10mm，在牵张完成后第8和16周分别处死4只动物，取双侧关节作组织学和扫描电镜研究。结果：下颌一侧DO术后双侧髁状突发生适应性改建，髁突表面超微结构正常。结论：在适当的牵张条件下延长一侧下颌骨不会对TMJ造成病理性损害。     

Changes in the condyle and disc in response to distraction osteogenesis of the minipig mandible.

PURPOSE: Distraction osteogenesis (DO) is a commonly used technique for mandibular lengthening, but changes in the temporomandibular joint have not been well documented. The purpose of this study was to evaluate the effect of DO, at varying rates, on the mandibular condyle and articular disc. MATERIALS AND METHODS: Semiburied distractors were placed via submandibular incisions in 15 minipigs. Two unoperated animals served as controls. The protocol consisted of 0 day latency and rates of 1, 2, or 4 mm/d for a 12-mm gap. After the animals were killed (0, 24, or 90 days), ipsilateral and contralateral condyles and discs were harvested and evaluated to determine changes in 1) condylar form and size, 2) condylar surface, and 3) the articular disc. RESULTS: Articular surfaces of the condyles in control animals were smooth, with no irregularities or erosions. In animals undergoing distraction, ipsilateral condyles showed increasing changes in morphology and AP dimension, and surface contour irregularities as the DO rate increased. These changes were present, but to a lesser degree, in the contralateral condyles. Articular discs of both ipsilateral and contralateral sides showed variable thinning at the medial aspect at end DO. After 90 days, changes in the condyles and discs were reduced by remodeling except in the 4 mm/d DO groups. CONCLUSIONS: Results of this preliminary study indicate that gross changes occur in condyles and discs after unilateral mandibular DO. These changes are more severe at faster distraction rates (4 mm/d) and tend to resolve during neutral fixation when a rate of 1 mm/d is used.     

山羊颞下颌关节强直病理模型的建立

目的：建立山羊颞下颌关节强直病理模型,以进一步探讨颞下颌关节强直的病因。方法：取山羊9只,随机等分为3组。分别采用破坏关节表面软骨、破坏关节表面软骨＋去除关节盘、破坏关节表面软骨＋去除关节盘＋关节腔内植骨3种不同手段制作模型。术后3个月后观察颞下颌关节强直的形成情况。结果：关节软骨破坏＋去除关节盘组全部发生强直;保留关节盘者无一例发生强直;植骨组仅2只山羊发生关节黏连。强直者,光镜下表现为髁突与关节窝间类骨质形成;未强直者。光镜下表现为关节表面破坏。结论：去除关节盘＋关节软骨破坏形成的TMJ强直,具有可重复性、短期内发生以及良好的相似性,接近人类病变发生的过程．是一种较好的制作颞下颌关节强直模型方法。     

Changes in parathyroid hormone-related protein and 3-dimensional trabecular bone structure of the mandibular condyle following mandibular distraction osteogenesis in growing rats.

PURPOSE: Distraction osteogenesis (DO) is commonly performed for mandibular reconstruction during the growth period. We tested the hypothesis that parathyroid hormone-related protein (PTHrP) in mandibular condylar cartilage and underlying trabecular bone in growing individuals undergo changes in response to distraction forces. MATERIALS AND METHODS: Forty-eight 6-week-old male Sprague-Dawley rats were used. Animals underwent unilateral mandibular distraction using a distractor that we devised, and unoperated animals were evaluated as controls. DO procedure was performed: 3 days' latency period, 0.4 mm/day rate, total 4.0 mm. Changes in cartilage morphology, PTHrP activity, and 3-dimensional trabecular bone structure changes measured by micro-computed tomography were examined at 0, 2, 4, and 6 weeks of consolidation. RESULTS: A marked irregularity was noted in the superior portion of the distracted side's condylar cartilage that resolved after distraction ceased. PTHrP was more strongly expressed in the hypertrophic layer of condylar cartilage on the distracted side than in controls, up to 6 weeks after the end of distraction. Subchondral trabecular bone volume, percent bone volume, and trabecular number in the superior and posterior regions of the condyle decreased significantly by 2 weeks after distraction. These parameters returned to normal in the posterior condyle, but not in the superior part of the condyle by 6 weeks following distraction. CONCLUSION: These results suggest that unilateral mandibular distraction in growing rats causes temporary morphologic alterations of trabecular bone structure on the distracted side accompanied by increased production of PTHrP in the mandibular condyle.     

Reconstruction of mandibular condyle by transport distraction osteogenesis: Experimental study in rhesus monkey.

PURPOSE: This study investigated histomorphologic changes in the newly formed condyle reconstructed by transport distraction osteogenesis through a nonhuman primate model. MATERIALS AND METHODS: Six adult rhesus monkeys were used in this study. Bilateral condyles and articular discs were extirpated, and the technique of transport distraction osteogenesis was carried out to reconstruct the condyles. X-ray and 3-dimensional (3D) computed tomography (CT) scanning films were taken at various intervals. Two monkeys were killed respectively at 4, 12, and 24 weeks after completion of distraction; the transport segments and the distracted calluses were harvested and processed for histologic examination. The original condyles removed at surgery served as normal control. RESULTS: Open bite was seen in all animals postoperatively and diminished at the end of distraction. Bone regeneration was perfect in the distraction gap between the transport disc and the pre-existing mandible. The bony transport disc gradually remodeled to a neocondyle that was similar to the original condyle in the appearances and structures. The head of neocondyle was covered with a fibrous cap, which might play the role of an articular disc. CONCLUSION: A neocondyle with functional shape can be created by transport distraction osteogenesis. This suggests that this technique is an alternative method for reconstruction of the mandibular condyle.