亚历山大矫正技术减数矫治的稳定性研究

目的探讨亚历山大矫正技术在拔牙矫治中的应用及其效果的稳定性。方法选择15例恒牙患者(男8例,女7例),开始矫治时间10.3~16.2岁。设计减数4个第一前磨牙,采用亚历山大矫正技术,对矫治前(T1)、矫治后(T2)及保持结束后平均27.8个月的观察期(T3)内的模型进行测量。统计学处理采用配对t检验。结果上下尖牙之间的宽度在保持后的回访期内分别减小0.37mm和0.72mm,但P>0.05;虽然上、下颌牙弓排列在回访期内分别有0.53mm和0.98mm的拥挤,但同样无统计学意义。由于内收前牙,矫治后的上、下颌牙弓长度明显减小(P<0.01),在回访期内分别增加0.28mm和0.05mm,但P>0.05。结论初步研究结果表明,亚历山大矫正技术中矫治器设计及其矫正理念有利于拔牙矫正后的稳定。但长期稳定性尚待进一步观察。     

Expression and significance of stromal cell-derived factor-1alpha and its receptor CXCR4 in human dental pulp cells

OBJECTIVE: To investigate the expression of CXCR4 in cultured human dental pulp cells (HDPC) in vitro and the corresponding ligand SDF-1alpha level of HDPC supenatants stimulated by lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-alpha), and to explore the role of SDF-1alpha on the proliferation and the migration of HDPC. METHODS: The expression of CXCR4 in HDPC was detected by immunocytochemistry technique and indirect immunofluorescence technique. The culture supernatants of HDPC were collected after HDPC had been simulated by LPS and TNF-alpha of different concentrations for 48h and then the SDF-1alpha level was assayed by quantitative sandwich ELISA. Meanwhile, the effects of recombinant human SDF-1alpha (rhSDF-1alpha) on the proliferation and the migration of HDPC at different concentrations were observed by MTT and Boyden Chamber Assay. RESULTS: CXCR4 was expressed in cytomembrane of HDPC and SDF-1alpha was secreted into their normal cell supernatants with a concentration of (4513.55 +/- 962.92) ng/L. The secretion of SDF-1alpha was both significantly decreased by stimulation with LPS and TNF-alpha (P < 0.05). In addition, rhSDF-1alpha stimulated the HDPC proliferation at the concentrations of 50, 100, 200 microg/L (P < 0.01) and increased the chemotactic migration of HDPC significantly after 9h's incubation with the concentrations of 50, 100 microg/L (P < 0.05). CONCLUSIONS: SDF-1alpha accelerated the proliferation and the migration of HDPC which expressed CXCR4. SDF-1-CXCR4 axis may play a role in repair of pulp injury.     

味觉出汗综合征的临床分析

为了观察味觉出汗综合征的发病情况,对100例行腮腺区手术的患者,作了客现的碘-淀粉试验检查。结果表明:行浅叶切除术者,其发病率(100％)明显高于包括肿瘤及其周围部分正常腺体的区域切除术者(发病率为18.18％)。放射治疗虽可降低味觉出汗综合征的发病率,但放射治疗后仍有复发可能。     

非血管化游离骨移植中细胞活力的实验研究

目的 :探讨非血管化游离骨块中细胞存活能力及数量与离体时间的关系。方法 :取狗非血管化游离髂骨块 ,在离体 2 5～ 15 0min的不同时间点 ,消化骨块获得细胞 ,进行活细胞计数。对消化获得细胞体外培养2 4h后 ,再进行活细胞计数 ,分析细胞存活与离体时间的关系。结果 :在离体 2 5～ 15 0min时间内 ,骨块细胞的存活率从 91.96%降至 9.5 2 %。统计学检验 ,2 5min组与 70min以前组之间没有统计上的差别 ,P >0 .0 5 ;2 5min组与 70min及其以后组之间有明显差别 ,P <0 .0 1。培养 2 4h后 ,以上各时间点的细胞存活率则从88.73 %到 3 .88% ,组间差别与刚离体时相同 ,但 70min后的各组活细胞率明显下降。结论 :非血管化狗游离髂骨块的离体时间对其中的细胞存活有明显影响 ,离体 70min可能是其关键点 ;在非血管化游离骨移植中 ,尽量缩短骨块的离体时间 ,有利于保存更多的活细胞     

氟离子缓释正畸粘接剂缓释性能的研究

目的全面了解树脂型氟离子缓释正畸粘接剂(fluoride releasing adhesive，FRA)缓释氟离子的性能，建立一套评价FRA氟离子缓释性能的测试方法及指标。方法测定并计算FRA在一定时间中累计氟离子释放量，绘制出时间—氟离子累计释放量趋势线，并计算每单位质量FRA有效氟离子释放量。结果时间—氟离子累计释放量趋势线显示，FRA在90d内能持续、稳定地释放氟离子，每单位质量FRA在90d内有效氟离子释放量为449μg/g。结论本实验FRA试样具有稳定缓释氟离子的能力。     

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目的探讨螺旋CT三维重建技术在埋伏尖牙正畸牵引中的应用价值。方法2006年3月至2007年12月,南京大学医学院附属口腔医院正畸科对12例颌骨内尖牙埋伏阻生患者进行螺旋CT检查、颌面骨三维重建,并与曲面断层X线片进行对比观察。结果CT三维重建能对颌骨内埋伏阻生尖牙准确定位,与颌骨内的实际情况所见完全一致,极大的提高了埋伏尖牙正畸牵引的成功率,有效地缩短了患者的治疗时间,减少了患者的痛苦。结论螺旋CT三维重建影像可以直观地显示埋伏阻生尖牙在颌骨内的生长情况,对上颌骨埋伏阻生尖牙的定位、治疗方案的制定具有重要指导作用。     

Thickness of posterior palatal masticatory mucosa: the use of computerized tomography

BACKGROUND: Periodontal plastic surgery is used to fulfill the esthetic and functional demands of patients. The palatal masticatory mucosa is the main donor site for connective tissue, and the thickness of the graft tissue obtained is an important factor for the success of this technique. The aim of this study was to measure the thickness of masticatory mucosa in the posterior palatal area using computerized tomography (CT). METHODS: The thickness measurements were performed on the images of 100 adult subjects who underwent CT on the maxilla for implant surgery. Twenty-four standard measurement points were defined in the hard palate according to the gingival margin and the middle palatal suture. The radiographic measurements were used after calibration. The data were analyzed to determine the differences in the mucosal thickness according to gender, age, tooth position, and depth of the palatal vault. RESULTS: The overall mean thickness of the palatal masticatory mucosa was 3.83 +/- 0.58 mm (range: 2.29 to 6.25 mm). Females had significantly thinner mean masticatory mucosa (3.66 +/- 0.52 mm) than males (3.95 +/- 0.60 mm) (P <0.0001). The thickness of the palatal masticatory mucosa increased with age. The mean thickness according to tooth site was 3.46 mm (maxillary canine), 3.66 mm (first premolar), 3.81 mm (second premolar), 3.13 mm (first molar), 3.31 mm (the base of the interproximal papilla of the first and second molars), and 3.39 mm (second molar). There was an overall increase in the thickness of the palatal masticatory mucosa as the distance from the gingival margin to the middle palatine suture increased, with the exception of the Ca-d (a point at 12 mm from the gingival margin of the canine) region. There was no significant difference in the thickness of the palatal masticatory mucosa between the groups with high or low palatal vaults. CONCLUSIONS: The palatal masticatory mucosa thickness increased from the canine to premolar region but decreased at the first molar region and increased again in the second molar region, with the thinnest area at the first molar region and the thickest at the second premolar region. The canine to premolar region seems to be the most appropriate donor site that contains a uniformly thick mucosa. CT can be considered an alternative method for the measurement of palatal soft tissue thickness.     

复发性口疮患者外周血T淋巴细胞亚群及Ig的观察

本文采用酸性α醋酸萘酯酶染色法(简称ANAE)及单向琼脂免疫扩散法对57例复发性口疮(简称RAU)患者的细胞免疫及体液免疫进行了测定。结果表明:(1)复发性口疮患者辅助性T细胞(Th细胞)明显低于正常人(P<0.01)。抑制性T细胞(Ts细胞)明显高于正常人(P<0.01)。Th/Ts比值下降。表明RA患者细胞免疫水平处于抑制状态。(2)血清IgG、IgA、IgM含量均高于正常人。提示:RA的发病机理与自身免疫功能的异常有密切关系。     

女性生长发育高峰期后安氏Ⅱ1类错(牙合)后部牙弓与颌骨宽度的分析

目的分析生长发育高峰期后女性安氏Ⅱ1类患者存在的后部牙弓及颌骨宽度不调,为安氏Ⅱ1类患者的早期治疗提供临床依据.方法选取30例生长发育高峰期后的女性安氏Ⅱ1类及35例安氏Ⅰ类患者,在模型上测量上下牙弓的宽度并计算宽度差值(PTID),在头颅后前位X线片上测量上颌宽度、鼻宽度及下颌角间宽度,用独立样本的t检验进行统计学分析.结果生长发育高峰期后的安氏Ⅱ1类患者均存在着上牙弓及上颌骨的狭窄,其PTID与安氏Ⅰ类患者相比具有显著性差异(P<0.05).结论生长发育没有改善安氏Ⅱ1类患者上颌后部牙弓及基骨的狭窄;对于安氏Ⅱ1类患者,早期通过扩大上牙弓的宽度,使下颌自由前伸,有利于Ⅱ类关系的纠正.     

Tissue oxygen tension and blood-flow changes in rat incisor pulp with graded systemic hyperoxia

The role of oxygen in the regulation of the pulpal microcirculation is unknown. This investigation is aimed to measure tissue oxygen tension and blood-flow changes in the pulp of rat lower incisors during graded systemic hyperoxia, and to determine the response of the pulpal vasculature to various oxygen tensions. Twenty-four Sprague-Dawley rats were anaesthetized and artificially ventilated with the appropriate gas mixture. Recessed oxygen-sensitive microelectrodes were used to measure pulpal tissue oxygen tension via a small access cavity filled with saline on the labial surface of the incisor. A laser Doppler flowmeter was used to record pulpal blood-flow. Inspired oxygen was increased stepwise from 20 to 100% in 20% steps. Systemic blood-gas concentrations were measured at each step. Systemic arterial oxygen tension at 100% oxygen ventilation reached 481.2 +/- 30.7% of the baseline at 20% oxygen breathing (n=21). Pulpal tissue oxygen tension did not change significantly whereas pulpal blood-flow fell dose-dependently to 74.6 +/- 5.0% at 100% oxygen ventilation (n=21). Systemic hyperoxia, therefore, induces a significant reduction in pulpal blood-flow whereas pulpal tissue oxygen tension remains relatively stable, indicating an oxygen-dependent local regulatory mechanism.