牙种植数字化全景X线片失真率的临床评价

目的:了解数字化全景片失真率的大小以及在临床效果评价中的指导意义。方法:对术前使用统一直径钢珠的放射模板56个修复病例162个种植体拍摄数字化全景X线片,应用Cliniview5.1分析软件对各部位钢珠进行测量3次,取均值。了解拍摄后影像中钢珠的变化情况。结果:采用数字化全景X线片技术可观察到上下颌骨不同区域钢珠失真率与标准钢珠直径差异很小,失真率范围为0.2%￣2%,不同区域钢珠测量值之间有明显差异(P〈0.05〉):下颌前牙区与下颌双尖牙区、下颌前牙区与下颌磨牙区、下颌双尖牙区与上颌磨牙区、上颌磨牙区与下颌磨牙区钢珠测量值之间存在显著性差异。结论:数字化全景X线片对拟种植部位骨量进行评估可得出准确的数据。尽管不同区域钢珠测量值之间存在差异,但并不影响其测量值应用于临床的准确性。     

OSAHS与无睡眠呼吸障碍老年腭咽及其周围组织结构的MRI比较研究

目的研究睡眠呼吸暂停低通气综合症(OSAHS)与无睡眠呼吸障碍的老年男性腭咽及周围组织结构的三维形态差异.材料与方法70岁以上老年男性18名,根据夜间多导睡眠监测结果,8人AHI＞10,定为OSAHS组(T1组);10人AHI≤10,为无睡眠呼吸障碍组(T2组).所有受试者均行磁共振(MRI)检查,对两组腭咽及周围组织的MRI测量结果进行比较.结果①OSAHS组腭咽体积、截面积明显小于无睡眠呼吸障碍组;②与无睡眠呼吸障碍组相比OSAHS组腭咽左右径明显小、前后径/左右径之比明显大.③OSAHS组腭咽侧壁厚明显大于无呼吸障碍组、脂间距也明显小于后者.④两组的腭咽前壁厚度、后壁厚度、脂肪垫体积、舌体积、软腭体积没有显著差异.结论老年男性OSAHS患者由于腭咽侧壁增厚及咽旁脂肪垫的挤压,使腭咽左右径减小、截面积减小且形状趋圆,腭咽体积也减小.     

骨髓间充质干细胞移植促进大鼠下颌骨牵张成骨的实验研究

目的:探讨大鼠下颌骨牵张间隙内移植自体骨髓间充质干细胞,促进骨痂形成的可行性。方法:选用54只雄性SD大鼠,密度梯度离心法分离骨髓间充质干细胞(MSCs)。所有大鼠行右侧下颌骨牵张;并于术后随机分为试验和对照2组。牵张结束时,实验组牵张间隙内注射自体MSCs;而对照组只注射等量生理盐水。分别于固定期第2、4、8周分3批处死大鼠,进行放射学、组织学观察,并对骨组织形态计量学参数进行统计学分析(t检验)。结果:放射学和组织学观察表明,2组牵张间隙内均形成了骨痂组织,但实验组新生骨组织显著多于对照组。计量学分析也显示,各时间点实验组新生骨量(NBV1和NBV2)和新生骨小梁宽度(TNT)均显著高于对照组(P<0.01)。结论:牵张间隙内行自体骨髓MSCs移植,可有效促进新骨形成,缩短固定期;该方法对众多的颅颌面外科畸形的矫治极具价值。     

Cloning of hamster osteopontin and expression distribution in normal tissues and experimentally induced oral squamous-cell carcinoma

Osteopontin (OPN) is a non-collagenous extracellular matrix (ECM) protein expressed and secreted by several human cancers. This study investigated the expression pattern of OPN during development of oral squamous-cell carcinoma by using 7,12-dimethylbenz[a]anthracene (DMBA)-induced squamous-cell carcinomas in buccal pouch of syrian golden hamsters. We first identified the hamster OPN cDNA sequence by screening of a hamster calvariae cDNA library with a rat OPN cDNA probe. The resulting 1,449 bp of hamster OPN cDNA led to a deduced protein sequence of 305 amino acids containing several putative binding sites to integrins, CD44 receptors, calcium ions and hydroxyapatite, as well as multiple sites for phosphorylation, glycosylation and sulphation. Hamster OPN cDNA was then used as a probe to analyze the expression of OPN mRNA by Northern blot and in situ hybridization analyses of normal and malignant tissues. OPN mRNA was detected in several non-mineralized tissues as well as in mineralized tissues, but was not present in normal hamster buccal epithelium. DMBA-treated hamster buccal pouches expressed OPN mRNA as early as 4 weeks and displayed the highest level of expression at 15 weeks. The specimens treated with DMBA for 15 weeks exhibited histological features of squamous-cell carcinoma, presented microcrystalline deposits and showed OPN expression associated with malignant epithelium and tumor-associated macrophages. To summarize, our results suggest that buccal-pouch carcinogenesis of Syrian golden hamster may constitute an excellent experimental model to study the mechanisms by which OPN is associated with oral cancer pathogenesis, and to validate OPN-based therapeutic approaches to ameliorate oral cancer progression and metastasis.     

Soluble CD14 levels in gingival crevicular fluid of subjects with untreated adult periodontitis

BACKGROUND: This study determined soluble CD14 (sCD14) levels in gingival crevicular fluid (GCF) and their potential relationship to periodontal conditions in adult periodontitis. METHODS: GCF was collected from 15 patients with untreated adult periodontitis. sCD14 levels were determined by ELISA and presented as total amount (ng/site) and concentration (microg/ml). The periodontal examination consisted of plaque index (PI), bleeding index (BI), probing depth (PD), and clinical attachment level (CAL). PD and CAL were measured with an electronic probe. RESULTS: sCD14 was detected in all 15 subjects and was found in 59% (62/105) of the sampled sites. The percentage of sites with sCD14 varied greatly, ranging from 14% to 100%. The mean total amount of sCD14 was 1.71+/-0.40, range 0.03 to 5.41 ng/site; the concentration of sCD14 was 14.04+/-4.15, range 0.16 to 51.74 microg/ml. No significant difference in clinical data was found between the sites with and without detectable levels of sCD14. However, on the basis of the individual profile of sCD14 levels, i.e., those individuals with >50% of the sites containing sCD14 and mean levels of sCD14 >5.0 microg/ml, the 15 subjects were divided into a high sCD14 group (9 subjects) and a low sCD14 group (6 subjects). Compared to the high group, the low group showed greater mean PD and a higher percentage of sites with PD > or = 5.0 mm (P <0.05). Consistent with this, sCD14 concentrations showed a negative correlation with PD (r(s) = -0.636, P = 0.0174). CONCLUSIONS: The present study shows that sCD14 levels in GCF varied greatly among subjects with untreated adult periodontitis. Individuals with higher levels of sCD14 in GCF and more sites containing sCD14 had fewer deep pockets. The negative correlation between GCF sCD14 levels and probing depth implies a crucial role of sCD14 in bacterially induced periodontal destruction. The relationship between GCF sCD14 levels and probing depth warrants further investigations.     

咽旁颞下区的外科解剖钥匙──茎突

目的研究茎突毗邻关系，为咽旁颞下区手术提供外科解剖基础。方法测量颅骨。结果茎实根部深面有颈静脉孔，两者相距约3mm。颈静脉孔前有动脉管外口，分隔两者间的骨板下缘厚约1．87mm。在颈动脉管外口前外方有蝶骨角棘，二者相距约6．5mm。角棘之外侧有颞下颌关节窝，之前方为棘孔。棘孔之前内侧有卵圆孔。结论茎突可作为咽旁颞下区的外科解剖钥匙。     

ICRF154,加热对腺样囊性癌ACC-2细胞放射增敏的实验研究

目的研究ICRF154和加热对腺样囊性癌ACC－2细胞放射增敏的作用。方法以腺样囊性癌ACC－2细胞作为实验模型，用新抗癌药ICRF154在乏氧条件下研究该药的放射增敏性以及加热对放射的增敏效应。结果在0．2mmol／L浓度和2个小时作用时间下，ICRF154对ACC－2细胞有放射增敏作用，增敏比为1．22、放射后加热43℃，30分钟对ACC－2细胞有显著的放射增敏作用，增敏比为1．51。用上述浓度和作用时间ICRF154，作用于ACC－2细胞后进行照射，照华后即行加热43℃，30分钟，增敏比为1．67，表明ICRF154和加热的放射增敏作用有加成效应。结论ICRF154的放射增敏机制可能与其抑制拓扑异构酶Ⅱ，从而抑制DNA损伤的修复有关。     

非调和型正畸粘接剂的粘接强度考察

采用一种自制的非调和型正畸粘接剂,考察了牙釉质与正畸托槽在五种实验条件下的粘接抗张强度。结果表明该粘接剂不需调和,操作时间充裕,具有足够的初始粘接强度和长期粘接强度,其平均粘接抗张强度大于7MPa,特别适用于对多个正畸附件的粘接。     

基质金属蛋白酶-7和c-myc在口腔鳞状细胞癌中的表达和意义

目的研究基质金属蛋白酶-7(MMP-7)与c-myc在口腔鳞状细胞癌组织中的表达及其意义。方法应用免疫组化EliVisionTM法分别检测MMP-7和c-myc在49例口腔鳞状细胞癌和5例正常口腔黏膜上皮中的表达情况。结果1)MMP-7和c-myc在口腔鳞状细胞癌组织中的阳性表达率分别为83.7%和77.6%。2)在不同病理分级、不同临床分期和有无淋巴转移的口腔鳞状细胞癌组织中MMP-7阳性表达率的差异有统计学意义(P<0.05)。3)在不同病理分级和有无淋巴转移的口腔鳞状细胞癌组织中c-myc阳性表达率的差异亦有统计学意义(P<0.05)。4)口腔鳞状细胞癌组织中MMP-7和c-myc的表达呈正相关(P<0.05)。结论MMP-7和c-myc在口腔鳞状细胞癌组织中均有高表达,在口腔鳞状细胞癌的发病过程中,其高表达具有协同效应,共同促进口腔鳞状细胞癌的发生和发展。     

渐进性咬合紊乱导致兔髁突退行性变的研究

目的 探讨渐进性咬合紊乱是否可导致兔髁突软骨退行性变。方法 27只5月龄雄性新西兰大白兔，随机分为渐进性咬合紊乱组(A组)、操作对照组(B组)和空白对照组(C组)。A组动物以正畸用橡皮圈分别将一侧上颌和对侧下颌第一前磨牙向近中牵拉，以形成上下牙不吻合接触的咬合紊乱；B组作结扎钢丝操作对照，不牵拉。分别在6月龄、7月龄、8月龄时取材，各时间点每组取材3只实验动物，对双侧髁突作组织学观察和测量。结果 B、C两组髁突软骨表现无明显差异，A组有明显随时间延长而加重的退行性变，表现为髁突前、中部软骨变薄，肥大层软骨不连续，局部组织纤维化；髁突后部软骨增厚，增殖层未成熟细胞比例增加。结论 渐进性咬合紊乱可导致兔髁突软骨退行性变。