上颌第二磨牙的形态学研究

上颌第二磨牙的形态比较复杂且存在变异,临床的解剖位置又比较靠后,给牙髓和牙周病的治疗带来了很大困难。所以,掌握上颌第二磨牙的形态对临床治疗具有指导性的意义。本文系统地回顾了上颌第二磨牙的研究方法和进展,并结合临床对上颌第二磨牙的牙冠和牙根等外部形态以及髓腔和根管形态等内部结构进行了较全面的综述。根管治疗成功的关键是对髓腔解剖的理解和掌握,所以,充分掌握牙根和根管形态并了解可能存在的变异,才能更好地进行治疗。     

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目的    探讨龈下残根正畸牵引后桩冠修复可行性。方法    2007—2009年中国医科大学口腔医学院修复门诊转诊至正畸科的严重牙体缺损病例12例（12颗牙）,其龈下残根（牙根长度足够）经完善的根管治疗后先行纤维桩树脂桩核修复,在树脂核上黏接正畸托槽,使托槽尽量靠近龈方,在残根近远中4～6颗牙（每侧2～3颗牙）上黏接托槽,将一段长度适中的镍钛弓丝结扎固定在托槽上,利用弓丝的弹性形变复位达到牵引残根的作用。按桩冠要求制备基牙,修整桩核,制备烤瓷冠,使修复后的烤瓷冠边缘与根面缺损区边缘完全密合,完成修复。 结果    修复2年后桩冠修复体仍然固位稳定,根冠边缘密合,无松动、叩痛,牙龈无明显增生、炎症,牙周组织健康。X线检查根尖周围组织正常,无根尖周阴影,根尖周牙周膜连续,无骨质吸收,无牙槽骨吸收,牙根无复发回缩。 结论    龈下残根经正畸牵引后行桩冠修复是可行的。     

Orthostatic headache as the presenting symptom of cervical spine metastasis

Orthostatic headache is a key symptom of intracranial hypotension; however, not all orthostatic headaches are caused by cerebrospinal fluid leaks leading to intracranial hypotension. We report here the unusual case of a 68-year-old man presenting with orthostatic headache in which compression of the C3 spinal nerve root by metastatic tumor invasion may contribute to the development of his orthostatic headache.     

Maxillary first premolars: I. Morphology of the apical constriction

Objective

To investigated the apical constriction morphology of maxillary first premolars in the Chinese population.

Methods

Eighty recently extracted human maxillary first premolars from a native Chinese population were used. The number and shape of apical constrictions were recorded under a dental operating microscope (DOM) at 12.5 × 2.5 magnification. After access preparation, a new K-file was inserted into the canal until the tip of the file was just seen at the apical constriction under the DOM. The teeth with files in the canals were X-rayed from a mesiodistal direction using a direct digital radiography (DDR) system, and the distance between the file tip and the center of radiographic apex was directly measured from the computer screen using DDR measurement software.

Results

The percentage of teeth with an apical constriction was 78.5% (102/130). The most common apical constriction shapes were oval (55.9%) and round (35.3%). The mean distance between the apical constriction and the anatomical tip of the root was 0.61 mm, and 84.3% (86/102) were within 1 mm.

Conclusion

The most common shape of an apical constriction was oval or round, and the distance to the apex was mostly within 1 mm, indicating that root canal therapy should stop 1 mm from the radiographic apex.     

氢氧化钙在根管消毒中的疗效观察

目的：观察氢氧化钙在根管消毒中的疗效。方法：168颗急性根尖周炎患者随机分为A、B两组。A组为氢氧化钙组（CH）;B组为甲醛甲酚组（FC）。对两组治疗后的临床效果进行评价。结果：治疗后两组疼痛均完全消失。但时间差异明显,1天内A组有效率为77．22％,B组为20％。1周后,临床体征也明显改善,A组疗效优于B组,有显著性差异（P〈0．05）。结论：氢氧化钙是一种较理想的根管消毒药物。     

中医药疗法治疗神经根型颈椎病的研究近况

目的:综述近年神经根型颈椎病的中医药疗法治疗进展,肯定中医药疗法的疗效,为临床应用提供有力的依据。方法:根据相关文献的内容从手法、中药、针灸、综合疗法等4个方面进行分析,肯定中医药疗法的有效性和优越性。结论:中医药疗法疗效确切,但安全性、规范性等有待于进一步探讨。     

蕨麻正丁醇部位对缺氧损伤心肌细胞的保护作用

[目的]研究蕨麻正丁醇部位对缺氧损伤心肌细胞的保护作用。[方法]建立大鼠原代培养心肌细胞缺氧损伤模型,采用噻唑蓝(MTT)法检测心肌细胞代谢活力;胎盼兰染色法检测细胞成活率;比色法测定细胞外乳酸脱氢酶(LDH),肌酸激酶(CK)活性及细胞内超氧化物歧化酶(SOD)活性和丙二醛(MDA)含量。[结果]与模型组比较,蕨麻正丁醇提取部位各剂量组细胞代谢活力及细胞成活率显著提高(P<0.01),并均可显著减少缺氧损伤引起的LDH、CK的外漏量(P<0.01),提高细胞SOD活性(P<0.01),减少MDA的产生(P<0.01或P<0.05)。[结论]蕨麻正丁醇部位具有抗心肌缺氧损伤作用,其途径之一可能与其抗自由基氧化的能力有关。     

Image analysis of time-lapse movies--a precision control guided approach to correct motion artefacts

In long-term time-lapse studies of cell migration, it is often important to distinguish active movement of individual cells from global tissue motion caused, for instance, by morphogenetic changes, or due to artefacts. We have developed a method to define and correct global movements. This is realized by the sequential morphing of image sequences to the initial image based on the position of immobile reference objects. Technically, the approach is implemented in ImageJ, using the plugin UnwarpJ. We describe an efficient way to select parameter settings such as to optimize image correction. To this end, we implemented a strict statistical control that allows to quantify image registration quality. We document this approach using a time-lapse sequence of migrating interneurons in slice cultures of the developing cerebellum.