不同去势时间对大鼠牙槽骨微结构影响的比较研究

目的 比较不同去势时间对大鼠牙槽骨微结构的影响,探讨牙槽骨骨质疏松大鼠模型建立成功的参数。方法 24只6月龄雌性SD大鼠,随机分为4组：（1）对照组1（Sham1）;（2）去势组1（OVX1）;（3）对照组2（Sham2）;（4）去势组2（OVX2）。分别在全麻下行假手术和双侧卵巢去势术。于术后3个月和4个月处死各组大鼠,取双侧上颌骨标本,通过Micro-CT扫描、HE染色、抗酒石酸酸性磷酸酶（TRAP）染色、Van Gieson染色、荧光双标观察并分析牙槽骨微结构的变化。结果 去势3个月后OVX1组与Sham1组大鼠相比,体重增加25.09%（P<0.01）;牙槽骨骨体积分数（BV/TV）、骨小梁数目（Tb.N）、骨小梁分离度（Tb.Sp）,牙骨质界-牙槽嵴顶（CEJ-ABC）距离无改变（P>0.05）,骨小梁宽度（Tb.Th）降低了12.44%（P<0.05）,破骨细胞数量增加了40.12%（P<0.01）;骨形成沉积率（MAR）无明显改变（P>0.05）;去势4个月后OVX1组与Sham1组大鼠相比,体重进一步增加了26.25%（P<0.01）,BV/TV、Tb.Th、MAR分别降低了11.15%、17.22%和38.45%（P<0.01）,Tb.Sp和破骨细胞数量分别增加了81.89%和35.67%（P<0.01）,Tb.N和CEJ-ABC距离无变化（P>0.05）,HE和Van Gieson染色均表明OVX2组大鼠牙槽骨骨量降低,骨髓腔面积增加,骨小梁微结构破坏、变细,部分区域发生断裂。结论 6月龄雌性SD大鼠去势4个月后,牙槽骨发生明显骨质疏松,可作为合适的牙槽骨骨质疏松大鼠模型参数的理论依据。     

MMP-9在去势大鼠正畸牙齿压力侧牙槽骨表达的研究

目的:比较不同正畸加力时间牙槽骨压力侧破骨细胞数和MMP-9表达水平,探讨骨质疏松对正畸力作用下骨代谢的影响.方法:取6月龄雌性Wistar大鼠50只,随机分为去势组和对照组(每组25只).去势组大鼠切除双侧卵巢建立骨质疏松模型.术后6个月,于两组大鼠上颌双侧磨牙与中切牙之间安装矫治器,并施以0.49 N的拉力.分别于加力后0、5、7、10、14 d取材,免疫组化及抗酒石酸酸性磷酸酶(TRAP)染色法检测各组大鼠上颌第一磨牙压力侧牙周组织中MMP-9表达水平及破骨细胞数.结果:去势组和对照组大鼠移动牙齿压力侧MMP-9表达水平及破骨细胞数均随加力时间延长而增加,加力7d时达到高峰,10d后逐渐降低;相同加力时间点内两组相比,去势组MMP-9的表达和破骨细胞数均高于对照组,除加力14 d时两组破骨胞数无统计学差异(P＞0.05)外,其他差异均有统计学意义(P＜0.05).结论:骨质疏松状态下大鼠正畸移动牙齿压力侧牙槽骨吸收活动增强.     

卵巢去势后大鼠牙槽骨及牙齿的组织学观察

目的 建立卵巢去势法大鼠骨质疏松模型,观察下颌牙槽骨及牙齿的组织学改变.方法 3周龄雌性SD大鼠40只,随机平均分为2组:去势组和对照组.术后1、3个月各取大鼠心脏血,用发光法测定血清雌二醇;比较两组体重增加的差异;下颌硬组织脱矿后苏木素-伊红(HE)染色,观察下颌牙槽骨及下颌牙的组织形态变化.结果 与正常组相比,去势组的雌激素水平显著下降(P<0.05),体重增加明显(P<0.05);松质骨内骨小梁变细,排列稀疏;下切牙前期牙本质层变薄.结论 去势法SD大鼠骨质疏松模型成熟可靠,下颌牙槽骨表现出明显的骨质疏松样改变,牙齿硬组织形成能力降低.     

甲状旁腺激素与雌激素对去势雌性大鼠牙槽骨代谢的影响

目的 观察甲状旁腺激素与雌激素单独和联合应用对去势雌性大鼠牙槽骨代谢的影响。方法选用4月龄雌性Wistar大鼠66只,分成两组,分别为伪手术组（n=18）和去势组（n=48）。8周后各处死8只证实骨质疏松造模成功。剩余的伪手术组（A组,n=10）Wistar大鼠作为对照;将剩余的去势组Wistar大鼠随机分成4组,分别为去势组（B组）、去势加雌激素组（C组）、去势加甲状旁腺激素组（D组）、去势加雌激素和甲状旁腺激素组（E组）,每组10只。A组和B组注射生理盐水（1 mL·kg-1）;C组注射苯甲酸雌二醇（10 μg·kg-1）; D组注射甲状旁腺激素（20 μg·kg-1）;E组注射苯甲酸雌二醇（10 μg·kg-1）和甲状旁腺激素（20 μg·kg-1）。隔日腹腔注射1次,用药8周。治疗后处死大鼠并测定牙槽骨骨密度,观察每组大鼠骨组织形态计量学参数及血清钙、磷、碱性磷酸酶（ALP）水平。结果去势手术8周后,去势组大鼠牙槽骨密度明显低于伪手术组（P<0.05）。用药8周后,C、D、E组骨密度、骨小梁面积百分比（%Tb.Ar）、骨小梁宽度（Tb.Th）和骨小梁数量（Tb.N）较B组均有明显提高,其中E组提高最明显（P<0.05）。各组血清钙磷值无明显改变（P>0.05）,B组ALP值较A组明显升高（P<0.05）。结论间歇性、小剂量注射甲状旁腺激素能增加去势大鼠牙槽骨的骨密度和改善骨结构,与雌激素联合使用对骨质疏松的治疗有协同作用。     

软食对青春期大鼠下颌后牙区牙槽骨微结构的影响

目的 :观察软食喂养引起的机械负荷改变对青春发育期大鼠下颌后牙区牙槽骨微结构的影响。方法 :取16 d龄雄性SD大鼠20只,随机分为软食组(SD组)和硬食组(HD组),每组各10只。7周后,运用显微CT(Micro CT)技术观察分析2组大鼠下颌第一磨牙(M1)区牙槽骨的松质骨微结构,苏木精-伊红染色对脱钙后的下颌骨M1区域进行组织学观察。结果:Micro-CT结果显示,较HD组而言,SD组M1区松质骨的骨小梁厚度(Tb.Th)显著减少(P<0.01),骨小梁间距(Tb.Sp)显著升高(P<0.05);组织学结果显示,SD组M1牙槽纵隔以及根尖区域骨小梁较HD组稀疏、变细,骨髓腔增大,近牙周韧带区域骨细胞分布减少。结论:软食喂养引起的负荷降低减少了下颌后牙的牙槽骨骨小梁的厚度、增加了骨小梁间距,从而影响了其骨微结构。     

正畸牙齿移动过程中牙槽骨的Micro-CT形态学研究

目的了解不同矫治力作用下牙槽骨骨小梁显微结构变化情况,探索正畸过程中牙槽骨骨小梁结构变化规律,为正畸临床提供指导。方法选择11周龄sD雄性大鼠22只,分别施加100g和30g矫治力,近中移动上颌第一磨牙建立实验动物模型。2周后处死动物,获得上颌第一磨牙及其周围牙槽骨。使用Skyscan1172型Micro．CT扫描大鼠上颌牙槽骨骨小梁,计算骨小梁显微结构的各项参数并进行统计学分析。结果施加矫治力2周后,轻力组、重力组牙槽骨骨体积分数（BV／TV）都较对照组显著升高,重力组牙槽骨骨小梁间隙（Tb．Sp）比对照组明显减少（P〈0．05）,但重力组和轻力组之间没有显著性差别。结论在正畸矫治力产生的压应力作用下,牙槽骨进行相应的改建。     

葛根素影响去势雌性大鼠牙周炎症的实验研究

目的探讨葛根素对去势SD大鼠牙周炎形成和发展的影响。方法雌性3月龄SD鼠60只分为6组,A组（正常对照组）、B组（牙周结扎组）、C组（去势组）、D组（去势结扎组）、E组（去势葛根素组）、F组（去势结扎葛根素组）各10只。C、D、E、F组大鼠分别经腹部切口摘除双侧卵巢;B组作假手术。B、D、F组在大鼠右侧上颌第一磨牙牙颈部结扎1根0.2 mm不锈钢丝。E、F组大鼠术后1周开始每天腹腔注射100 mg/kg葛根素;B、C、D组大鼠每天腹腔注射相应剂量生理盐水。给药12周后分别观察各组大鼠牙槽骨吸收值、血钙值、血磷值、血清碱性磷酸酶含量以及牙槽骨组织病理学改变。结果所有牙周结扎组都表现出不同程度的局部牙周炎症;各去势组大鼠都存在不同程度的骨质疏松改变,注射葛根素组病理学表现较未注射葛根素组为轻。血清钙水平去势各组与正常对照组差异均有统计学意义（P〈0.05）;血清碱性磷酸酶水平去势各组与正常对照组差异有统计学意义（P〈0.05）;血清磷水平在各组间差异无统计学意义（（F=1.764 1,P〉0.05）。A、C、E组未观察到明显的牙周骨质吸收,B、D、F组牙槽骨吸收值分别为（0.21±0.08）mm、（0.55±0.07）mm、（0.42±0.10）mm,3组两两比较,差异均有统计学意义（P〈0.01）。结论在局部刺激因素存在的前提下,雌激素水平降低可增加大鼠对牙周炎症的易感性和反应程度;葛根素对伴随雌激素降低的牙周炎的发生发展有一定的阻缓作用。     

糖尿病大鼠牙槽骨骨密度的变化

为了评价糖尿病大鼠牙槽骨代谢情况，采用放射免疫分析检测其血清骨钙素浓度，以双能量Ｘ线骨密度测量仪测量牙槽骨骨密度并结合组织学观察。结果表明，糖尿病大鼠血清骨钙素浓度升高，股骨与上、下牙槽骨骨密度降低，牙槽骨骨小梁变细变疏、骨吸收活跃，新骨形成减少。本研究结果提示，糖尿病大鼠牙槽骨骨吸收活跃，骨形成缓慢，有骨质疏松倾向。     

雄激素对大鼠牙槽骨骨量的影响

目的：探讨去睾丸对大鼠牙槽骨骨量的影响。方法：24只雄性SD大鼠随机分为3组：假手术组（Con）、去睾丸组（ORX）和雄激素治疗组（TP）。除Con组外,其余行双侧睾丸摘除术。Con组和ORX组给予溶媒5ml/kg/d灌胃,TP组给予丙酸睾丸酮5mg/kg/d灌胃。实验12周后取大鼠的牙槽骨,脱钙,切片,染色,用骨形态计量学方法测量牙槽骨松质骨的骨量,计算牙槽骨的骨静态学参数。结果：与Con组相比较,ORX组牙槽骨骨小梁厚度降低（P〈0.05）,其他变化均不明显。结论：雄激素缺乏使大鼠牙槽骨有丢失趋势,但不明显。     

OPG缺失后小鼠下颌骨微结构增龄性变化的Micro-CT评价

目的:基于Micro-CT评价骨保护素基因敲除(Opg-knockout,Opg-KO)型小鼠与野生型(wild type,WT)小鼠的下颌骨微结构增龄性变化,以便更好了解小鼠下颌骨的增龄性骨质改建情况。方法:分别采集6周、12月龄Opg-KO小鼠和WT小鼠各6只,采用Micro-CT扫描观察小鼠下颌骨三维结构,对感兴趣区域根分叉部位松质骨及前牙颏孔前缘区皮质骨骨微结构进行定量分析。结果:与WT小鼠相比,Opg-KO小鼠6周时第一磨牙根分叉处松质骨、髁突颈部、下颌角处、前牙颏孔前缘区均出现了明显的坑凹状吸收;12月时,这些区域破坏愈发严重,甚至出现穿孔;根分叉松质骨区域骨小梁平均厚度、骨密度、骨体积分数明显降低(P<0.05),骨小梁分离度明显升高(P<0.05);前牙颏孔前缘区皮质骨骨密度及骨体积分数明显降低(P<0.05)。结论:OPG缺失引起小鼠下颌骨发生严重的骨质破坏,随着年龄增加骨质破坏程度越发严重,并且松质骨骨微结构改变更显著。     

SD大鼠人造牙槽突骨缺损自愈率的显微CT评价

目的:采用显微CT评价SD大鼠牙槽突不同大小骨缺损的自愈情况,为建立大鼠牙槽突裂标准缺损模型提供实验依据。方法:7周龄SD大鼠18只,随机分为A、B2组,采用手术方法在大鼠右上颌建立3mm×3mm×2mm(A组)和4mm×4 mm×3mm(B组)的单侧牙槽突骨缺损。分别在手术后即刻、4周和8周处死取材。通过显微CT三维重建检测,定量分析骨缺损区的愈合情况。结果:4周时,A组的新骨形成量为80.42%,B组为54.35%;8周时,A组的新骨形成量为97.5%,B组为93.12%。2组标本的骨缺损在8周时均基本自愈。结论:显微CT可用于大鼠离体骨标本的骨量计算,2种不同大小的牙槽突骨缺损自愈率无明显差别。     

Alcoholic and isocaloric diet,but not ovariectomy,influence the apoptosis of bone cells within the alveolar bone crest of rats

ObjectiveStudies suggest that chronic alcoholism as well as oestrogen deficiencies may affect bones in general, including alveolar bone and, by doing so, increase individuals’ susceptibility to develop progressive periodontal disease. This paper aims to verify the influence of chronic alcoholism and/or oestrogen deficiencies in the apoptosis of bone cells of the alveolar bone crest region in rats.DesignInitially, 54 rats were divided into ovariectomized (Ovx) and Sham operated (Sham) groups. Thirty days after surgery, these two groups were equally sub-divided, and received, for 56 days, the following dietary intervention: alcoholic diet (with 20% alcohol solution,), isocaloric diet and ad libitum diet (free diet). Analysis was undertaken by immunohistochemistry, using an antibody to detect apoptosis (anti PARP p-85).ResultsWhen comparing the six experimental groups, no significant differences were observed in the apoptosis of bone cells. Also, there was no significant difference in the quantity of cells undergoing apoptosis when the animals from Ovx groups were compared with those from Sham groups. However, when comparing only different dietary groups, differences were observed between the groups ad libitum and isocaloric, to osteoblasts (p = 0.045); and ad libitum and alcohol, to osteocytes (p = 0.007).ConclusionIt is concluded that ovariectomy was not able to influence the rate of apoptosis of bone cells of the alveolar bone crest region in rats and that a possible influence of diet on apoptosis of osteoblasts and osteocytes cannot be ruled out.     

Histological and histomorphometrical changes in rat alveolar bone following antagonistic tooth extraction and/or ovariectomy

OBJECTIVE: To examine changes appearing in the alveolar bone following the removal of the mechanical stress of occlusal loading, as well as the added influence of estrogen deficiency on such changes. DESIGN: The right mandibular molars of female rats were extracted. After 8 weeks, 12 animals were ovariectomized (OVX), and the other 12 were subjected to sham surgery (sham). Four weeks after surgery, all rats were sacrificed. The left-half and right-half maxillas of the sham group (the sham-occluded side and the sham-extruded side, respectively) and right-half maxilla of OVX group (the OVX-extruded side) were examined by histological observation and bone histomorphometry. RESULTS: The vertical height of alveolar bone in the sham-extruded and the OVX-extruded sides increased as compared with that of the sham-occluded side. In both extruded sides, active bone formation occurred on the surface of the alveolar bone facing the periodontal ligament, but the bone marrow was expanded and the bone volume had decreased in the internal area of the alveolar bone. In the OVX-extruded side, the bone marrow expanded more remarkably than that of the sham-extruded side, and the highest percentage of osteoclast surface was detected. CONCLUSIONS: Around the extruded teeth, there were regional differences in bone dynamics between the internal area of the alveolar bone and the bone surface facing the periodontal ligament, and estrogen deficiency seems to have caused further loss of bone volume in the interior of the alveolar bone supporting the extruded tooth.     

成人前牙内收前后切牙牙槽骨高度变化的研究

目的：研究成人双颌前突患者前牙内收前后切牙区唇侧、舌侧牙槽骨高度的变化。方法：选取双颌前突成人患者15例，治疗需拔除4颗第一前磨牙行前牙内收，内收前后分别拍摄 CBCT 片，对其上、下颌8颗切牙唇舌侧牙槽骨高度进行测量和对比分析。结果：上、下颌切牙内收后唇侧牙槽骨高度均有不同程度升高，以下颌更为显著（P ＜0．05），舌侧牙槽骨高度降低（P ＜0．05）。结论：成人双颌前突患者切牙行大范围舌向移动时舌侧牙槽骨高度降低，临床治疗中应予以关注。     

Effect of sympathetic nervous activity on alveolar bone loss induced by occlusal hypofunction in rats

Objective

To elucidate the effect of sympathetic nervous activity on alveolar bone loss induced by occlusal hypofunction in rat molars.

Design

Occlusal hypofunction in the molar area was produced by attaching appliances to rat maxillary and mandibular incisors. In addition, a non-selective β-adrenergic receptor antagonist, propranolol, was administered orally to rats in drinking water to pharmacologically suppress sympathetic nervous activity. After 1 week, alveolar bones in all groups were examined by micro-CT, histomorphometry and histology to determine their trabecular bone phenotypes and histological changes.

Results

The marrow spaces of the interradicular alveolar bone of rat mandibular first molars (M1) increased in the occlusal hypofunction group (Group H) but not in the control group (Group C), whilst these decreased in rats in the occlusal hypofunction group that were administered propranolol (Group HB). Bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th) and trabecular number (Tb.N) for interradicular alveolar bone in M1 in Group H were significantly lower than those in Group C, whereas those in Group HB remained as high as those in Group C. The number of TRAP-positive cells in Group H increased compared to that in Group C, whereas it significantly decreased in Group HB.

Conclusions

These results suggest that sympathetic nervous activity may influence the alveolar bone loss induced by occlusal hypofunction.     

雌激素缺乏对大鼠牙槽骨吸收影响的实验研究

目的观察雌激素缺乏对大鼠牙槽骨吸收的影响。方法34只雌性SD大鼠随机分为4组。第1组假手术(n=8),第2组卵巢切除(n=9),第3组卵巢切除加牙周结扎(n=9),第4组卵巢切除、牙周结扎加雌激素治疗(n=8)。适应性喂养7天后行假手术或双侧卵巢切除术。第4组于术后第二天起皮下注射苯甲酸雌二醇．20μg／kg体重／次,三天一次。第3、4两组于卵巢切除术后28天,结扎丝结扎上颌第一磨牙诱导牙周炎。第63天处死全部大鼠。常规取材。观察牙用组织组织学改变。测量牙用骨丧失值(PBL)。比较牙用骨支持率(PBS)。检测血清碱性磷酸酶(ALP)。结果采用成组f检验,第1、2两组的PBL分别为0．398±O．147mm,0．663±0．132哪。PBS分别为O．588±O．058。0．440±0．197,组间差异均有统计学意义(P<0．05);第2、3两组的PBL、PBS组间差异均有统计学意义(P<0．05)。第3组的PBL为0．875±0．197mm,PBS为0．336±O．087;第3、4两组的PBL、PBS组间差别没有统计学意义(P>0．05),第4组的PBL为O．823±0．119mm,PBS为0．360±0．950。结论雌激素缺乏促进牙槽骨吸收,茵斑刺激加剧骨质疏松大鼠牙槽骨的吸收,雌激素替代治疗不能预防骨质疏松大鼠因茵斑刺激引发的牙槽骨吸收。     

雌激素对骨质疏松大鼠牙槽骨改建过程中IL-1表达的影响

目的:研究雌激素对骨质疏松牙槽骨改建过程中白细胞介素-1(IL-1)的分布及表达的影响,探讨雌激素对骨质疏松牙槽骨改建影响的机制。方法:利用大鼠卵巢切除术制成骨质疏松模型,并运用免疫组化染色方法及半定量分析,观察IL-1在骨质疏松及雌激素治疗后的牙槽骨中的表达变化。结果:IL-1在骨质疏松牙槽骨中的表达明显增强,阳性反应主要分布于破骨细胞、部分成骨细胞中,而经雌激素治疗后,IL-1的阳性表达明显下降。结论:雌激素对骨质疏松大鼠牙槽骨中IL-1的表达有明显的抑制作用。