预成纯钛修复体修复下颌骨缺损

目的：探讨应用反求工程和快速原型技术进行下颌骨缺损修复的设计并预制修复体的可行性。方法：应用反求工程和快速成型技术为4名患者完成了下颌骨缺损的修复体设计和制作，并进行了修复体植入手术。结果：修复体就位顺利，各部件达到设计位置，术后患者面部外形满意，咬合关系良好，下颌偏斜纠正。结论：反求结合快速成型能够完成下颌骨缺损的修复体的设计和预制，提高了手术精度，节省了手术时间，在颌骨缺损的个体化和定制化修复中有独特的优势。     

快速成型及曲面设计技术治疗对称性颌骨畸形

颌面部对称性畸形主要指面部中线或涉及中线两侧的骨性畸形 ,在临床上并不少见 ,例如鼻周围上颌骨骨质的凹陷 ,颏正中的短小、后缩等。以往这种畸形的治疗主要靠衬垫材料和采用正颌外科解决 ,虽然也可取得较好效果 ,但也存在衬垫材料塑形 ,正颌外科截骨等问题 ,手术医生将大量时间耗费在材料塑形上 ,而且很难达到精确修复 ;截骨手术创伤大 ,患者需要忍受较大痛苦 ,术后恢复时间长。鉴于上述缺点 ,近来出现了利用工科快速成型技术修复颌骨缺损的方法 ,获得了较好效果[1,2 ,3 ,4],它是利用患者CT数据资料 ,通过数据转换 ,在计算机上通过大型…     

上颌第一磨牙根管预备后的有限元模型的建立和受力分析

目的：采用有限元方法建立上颌磨牙根管预备后的三维有限元模型并进行受力分析。方法：采用Micro-CT扫描,应用Mimics 8.1、Geomagic studio 8、Unigraphics NX及Ansys9.0软件分别得到根管预备后上颌第一磨牙三维外形、实体模型和有限元模型,并对建立的模型进行了可靠性验证。结果：重建的三维有限元模型与实体模型具有高度的几何及力学相似性,网格质量较好。结论：将Micro-CT扫描技术、数字图像处理技术与有限元方法结合起来,建立了有效的根管预备后上颌第一磨牙三维有限元模型,为口腔生物力学提供了研究手段。     

内置式曲线牵张器修复下颌角缺损的实验研究

目的:探讨自行设计的曲线牵张器修复下颌角弧形骨质缺损的可行性,曲线式牵张成骨的方式及其特点。方法:山羊4只,建立左侧下颌角弧形缺损的动物模型,制造骨转移盘,用自行设计的内置式曲线牵张器行BDO整复,牵引过程中摄X线片,进行骨密度测定,观察牵引进度及牵引间隙的成骨情况。结果:4只山羊中1只术后第3 d死亡,1只在牵引的末期牵引钢丝折断,2只顺利完成牵引,X线观察及骨密度测定见骨转移盘成功地沿预定的路径被牵引至缺隙的另一侧,固定2个月后牵引间隙的骨质已经与正常骨质的密度无显著性差异。结论:自行设计的内置式曲线牵张器可以完成下颌角弧形骨质缺损的修复。     

基于反求工程和快速原型的下颌骨缺损的修复

目的 探讨应用反求工程和快速原型技术进行下颌骨缺损修复的设计和植入体制作的可行性。方法 应用反求工程和快速原型技术完成2例下颌骨缺损的修复体设计和制作，并行修复体植入术。结果 经计算机设计和严密制作的修复体术中仅数分钟顺利就位，各部件达到设计位置，术后患者面部外形与健侧对称，咬合关系良好，下颌偏斜纠正。结论 反求结合快速原型能够完成下颌骨缺损的修复体的设计和制造，提高了手术精度，节省了手术时间，在颌骨缺损的个体化和定制化修复中有独特的优势。     

Diagnostic accuracy of serum hyaluronic acid, FIBROSpect II, and YKL-40 for discriminating fibrosis stages in chronic hepatitis C

OBJECTIVES:  Noninvasive serum markers of liver fibrosis are being used as an alternative to liver biopsy. Currently available tests distinguish, with accuracy, only absent/minimal fibrosis (Ishak stages 0–1) and advanced fibrosis/cirrhosis (Ishak stages 4–6), but not intermediate fibrosis (Ishak stages 2–3). Our aim was to evaluate the diagnostic accuracy of hyaluronic acid (HA), FIBRO Spect II (FS-II), and YKL-40 (chondrex, human cartilage glycoprotein-39) in various clinically important categories of fibrosis, and further correlate these serum markers with digital quantification of fibrosis (DQF) and Ishak stages.
METHODS:  Serum HA, YKL-40, and FS-II were retrospectively assessed and correlated with Ishak stages and DQF scores in 75 patients with chronic hepatitis C (HCV). Spearman's rho statistics assessed relationships among all parameters, and receiver operator characteristic curves evaluated accuracy of each parameter when compared to the Ishak stages.
RESULTS:  All three serum markers and DQF correlated highly with one another ( P ≤ 0.01) and with Ishak stages of fibrosis. Among the serum markers, HA was effective in discriminating between Ishak stages 0–1 and Ishak stages 2–3 compared with FS-II, with an area under the curve of 0.76 versus 0.66 and a false-positive rate of 0.33 versus 0.67, respectively. All three serum markers predicted advanced fibrosis and cirrhosis. YKL-40 had the highest false-positive rates in all categories of fibrosis.
CONCLUSIONS:  HA can be utilized as a reliable surrogate marker in distinguishing three clinically relevant stages of fibrosis: absent/minimal, intermediate, and advanced/cirrhosis. HA should be considered as a cost-effective alternative to other serum markers for staging fibrosis and for determining the timing and selection of HCV treatment.     

Relationship between carotid artery atherosclerosis and bulb geometry

The carotid bifurcation is a common site of atherosclerotic plaque. Plaque development is thought to occur preferentially at geometrically predisposed areas such as arterial branch points. The aim of this study was to investigate the geometric and anatomical variables that contribute to the development of carotid plaque using three-dimensional (3D) ultrasound. Sixty-seven consecutive outpatients referred for elective coronary angiography underwent 3D carotid ultrasound scans for the purpose of carotid plaque quantification. Geometric quantification of the left and right carotid bulbs were performed retrospectively on this study population. Geometric values such as angle, area and length of the carotid bulb and the bifurcation were determined using QLAB software (Philips Healthcare). Plaque volume within the carotid bulb and artery branches was quantified using the stacked contour method. Pearson’s correlation and linear regression analysis were used to determine the relationship between anatomical variables and plaque volume. The mean age for the total patient population was 65.9?±?11.5 years. Carotid bulb inflow area (BIA) (r?=?0.28, p?=?0.001), bulb volume (BV) (r?=?0.21, p?=?0.01) and bifurcation angle (BifA) (r?=?0.18, p?=?0.04) showed a positive linear relationship with plaque volume. In contrast, internal carotid artery angle (ICAA) (r?=???0.18, p?=?0.04) and bulb flare (r?=???0.20, p?=?0.02) displayed a negative linear relationship with plaque volume. When adjusting for age and sex, only the BIA remained significant (β?=?0.18, p?=?0.04). Geometric variables were identified as potential risk factors associated with plaque volume in the carotid bulb. Further analysis of the evolution of the BIA as well as the relationship to other geometric variables could create a stronger predictive model of atherosclerosis as well as assist in preoperative planning.     

Sahel, savana, riverine and urban malaria in West Africa: Similar control policies with different outcomes

The study sites for the West African ICEMR are in three countries (The Gambia, Senegal, Mali) and are located within 750 km of each other. In addition, the National Malaria Control Programmes of these countries have virtually identical policies: (1) Artemisinin Combination Therapies (ACTs) for the treatment of symptomatic Plasmodium falciparum infection, (2) Long-Lasting Insecticide-treated bed Nets (LLINs) to reduce the Entomololgic Inoculation Rate (EIR), and (3) sulfadoxine-pyrimethamine for the Intermittent Preventive Treatment of malaria during pregnancy (IPTp). However, the prevalence of P. falciparum malaria and the status of malaria control vary markedly across the four sites with differences in the duration of the transmission season (from 4-5 to 10-11 months), the intensity of transmission (with EIRs from unmeasurably low to 4-5 per person per month), multiplicity of infection (from a mean of 1.0 to means of 2-5) and the status of malaria control (from areas which have virtually no control to areas that are at the threshold of malaria elimination). The most important priority is the need to obtain comparable data on the population-based prevalence, incidence and transmission of malaria before new candidate interventions or combinations of interventions are introduced for malaria control.