三维放疗计划优化技术减少头颈部癌放射性口干症

目的：观察三维放疗计划优化技术减少头颈部癌放射性口干症的效果。方法：对三类头颈部癌（肿瘤位中线、偏一侧、近中线偏一侧）按常规放疗和优化技术分别作三维放疗计划。放疗优化技术包括放射进路优化、多野、适形放疗和加楔形板。对患者的肿瘤、腮腺和脊髓作三维剂量分布和剂量一容积DVH直方图分析。20例头颈部癌放疗患者分成常规放疗组和新技术（优化）组行放射治疗，记录放疗前、放疗中、放疗后及随访期患者的口干症评分和全唾液量。结果：肿瘤位一侧及近中线偏一侧时，常规和新技术放疗时健侧腮腺放射剂量分别为51.8-64.3Gy和0.4-1.4Gy；肿瘤位中线时常规和新技术放疗腮腺放射剂量分别为51.8Gy和24.7Gy；放疗结束时，新技术组口干症发生率1/12（8.3％）。随访4-6月后降为0，放疗结束时常规放疗组口干症发生率7/8（87.5％），随访4-6月后为4/8（50％）。结论：三维放疗计划优化技术可以明显减少头颈部癌患者放疗后口干症的发生。     

Elevated serum IgG titer and avidity to Actinobacillus actinomycetemcomitans serotype c in Japanese periodontitis patients

AIM: The purpose of this study was to characterize serum antibody responses to different serotypes of Actinobacillus actinomycetemcomitans strains in various forms of periodontitis and to determine whether any specific type of A. actinomycetemcomitans was associated with any specific form of periodontitis in a Japanese population. METHODS: Sonicated whole cell and autoclaved serotype antigens of A. actinomycetemcomitans were used. Serum IgG titer and avidity to A. actinomycetemcomitans were measured by enzyme-linked immunoabsorbant assay (ELISA) and ammonium thiocyanate-dissociation ELISA, respectively, in 46 aggressive periodontitis patients (8 localized, 38 generalized), 28 chronic periodontitis patients, and 18 periodontally healthy subjects. The presence of A. actinomycetemcomitans in plaque and saliva samples was determined using polymerase chain reaction. RESULTS: Generalized aggressive and chronic periodontitis patients exhibited significantly higher IgG titers than healthy subjects to both sonicated and autoclaved antigens of serotype c strains, while IgG titer to serotype b (Y4) was significantly higher in localized aggressive periodontitis patients compared to healthy subjects. No A. actinomycetemcomitans was detected in localized aggressive periodontitis patients. A. actinomycetemcomitans-positive patients exhibited significantly higher IgG titer and avidity to serotype c than A. actinomycetemcomitans-negative patients. In A. actinomycetemcomitans-positive patients, a significantly positive correlation was observed between antibody titer and avidity to serotype c. A. actinomycetemcomitans-positive patients with generalized aggressive periodontitis showed lower IgG avidities to serotype c than those with chronic periodontitis, though no statistically significant difference was found. CONCLUSION: A. actinomycetemcomitans serotype c may play a significant role in chronic and generalized aggressive periodontitis, while A. actinomycetemcomitans serotype b may be associated with localized aggressive periodontitis in a Japanese population.     

Effect of using RNA interference to alter iNOS gene expression on the proliferation of tongue squamous cell carcinoma cell line Tca8113

This study used RNA interference (RNAi) to explore the effect of NO and inducible nitric oxide synthase (iNOS) on apoptosis and proliferation in the tongue squamous carcinoma cell line Tca8113. Tca8113 cells were transfected with the plasmid pGenesil-1, which expresses iNOS short hairpin RNA (shRNA), or the negative control plasmid pSilencer-HK, and the transfected cells were compared with untransfected cells. The expression of iNOS was detected by histochemistry, and apoptosis was detected by flow cytometry. The expression of iNOS was significantly lower in the pSilencer-iNOS group than in the pSilencer-HK and empty control groups. The apoptosis rate was significantly higher in the pSilencer-iNOS group than in the pSilencer-HK and empty control groups. Growth monitoring showed that proliferation was also inhibited in cells transfected with pSilencer-iNOS. RNAi gene silencing decreased iNOS gene expression, induced apoptosis, and suppressed proliferation in Tca8113 cells.     

微型种植钉的长度直径对生物力学的影响

目的对比评价临床常用的3种类型(不同长度、直径)微型种植钉的生物力学特点。方法应用种植钉48枚,新西兰大白兔8只。采用拉出试验,扭转强度试验,在即刻与愈合4周后进行生物力学测量。结果长度为6mm,直径为1.9mm的种植钉相对于同等长度,直径为1.5mm的种植钉在“种植后即刻”与“愈合4周”时,最大剪切力均表现出显著性优势。愈合4周后,直径为1.9mm的种植体在最大扭转强度上表现出显著性的优势。结论在骨质量较差的部位选择较大直径的种植体有利于种植体的稳定。     

类风湿性关节炎患者牙周骨丧失程度的临床研究

目的:揭示类风湿性关节炎患者关节炎严重程度与牙周骨丧失程度的相关性。方法: 70例类风湿关节炎患者根据牙周附着丧失与牙槽骨吸收程度分为2组:无、轻度骨丧失组和中、重度骨丧失组。分别检查患者晨僵持续时间、红细胞沉降率以及血清C反应蛋白,并进行分析。结果:经统计学分析, 2组在晨僵时间、红细胞沉降率及C反应蛋白水平均有显著性差异,中、重度组均高于无、轻度组。结论:类风湿关节炎患者牙周骨丧失的程度与其类风湿临床症状严重程度密切相关。     

倾斜种植体在上颌后牙区骨量不足患者中的应用

目的:探讨倾斜种植体作为一种避免上颌窦植骨的方法,应用于上颌骨后牙区骨量不足患者种植修复的可靠性。方法:2005年1月—2007年12月间,21例患者共27个固定桥修复上颌后牙缺失,分别使用ITI和Br覽nemark 2种种植系统共植入78颗种植体,其中34颗种植体采用倾斜植入,44颗轴向植入。所有患者均为上颌后牙区骨量不足无法直接接受常规种植体植入。种植体植入后常规愈合3个月,除1颗种植体失败外,其余种植体均功能性负载支持固定义齿修复,修复方式为黏结固位和螺丝固位。每例患者均于负载后12、24和36个月接受临床和放射学随访检查。采用SPSS11.0软件包对数据进行统计学处理。结果:上颌有1颗轴向种植体在术后2个月时失败,倾斜种植体无失败。随访时间为36个月。上颌轴向种植体的累积存活率为97.72%,倾斜种植体的累积存活率为100%,修复成功率为100%。随访期间,种植体周围软组织保持稳定,平均探诊深度和附着水平无明显变化。结论:倾斜种植体作为一种上颌骨后牙区骨量不足患者的治疗方法是可靠的,能有效避免植骨手术,并节约治疗时间。     

下颌骨应力分布的三维有限元分析

本文用三维有限元方法建立了人类下颌骨的力学模型,采用双侧下颌角加力,模拟了前牙及后牙咬合,对下颌骨的应力分布进行了计算分析。结果表明:应力在下颌骨下缘及牙槽嵴处明显,下颌内侧面应力改变较下颌外侧面明显。     

远缘链球菌中葡萄糖基转移酶催化活性区基因的克隆和初步表达

目的 :构建一株高效表达Streptococcussobrinus 6715中GTF -I催化活性区 (含有B细胞表位 )多肽的菌株 ,为抗GTF -I的单克隆抗体的检测和防治龋病亚单位疫苗的研究奠定基础。方法 :提取基因组DNA ,然后用PCR技术扩增出中目的肽段的约 1.1kb编码基因 ,并将其克隆至表达载体 pGEX -4T -1中构建 pGEX -gtf表达质粒。该质粒转化大肠杆菌JM 10 9后获得重组表达菌株。PCR筛选阳性克隆子。异丙基-β -D -硫代半乳糖苷 (IPTG)诱导 ,确定含有 pGEX -gtf的大肠杆菌JM 10 9的表达情况。 结果 :含有质粒pGEX -gtf的大肠杆菌JM 10 9能够表达GST -GTF融合蛋白。 结论 :成功扩增目的基因 ,并且把它定向克隆到表达载体pGEX -4T -1中构建表达质粒 ,并且该表达质粒能在大肠杆菌中进行表达     

影响人工骨植入隆鼻术效果若干问题的探讨

对影响致密多晶羟基磷灰石微粒人工骨植入隆鼻术效果的有关问题，如材料粒度的选择、植入床的设计和手术操作中的误差等进行了探讨，并提出了应注意的有关事宜。     

Dental implants for orthodontic anchorage

The purpose of this article is to review and update current concepts involving the use of dental implants for orthodontic anchorage. Topics to be discussed include indications, implant requirements (eg, materials, size, designs of dental implants), surgery and healing time, biomechanics and forces, loading time, implant maintenance, posttreatment considerations, and disadvantages.