弯曲牙

World Health Organization clinical trials to prove substantial, resulting in tooth decay due to the large population of harmful bacteria, the functional characteristics of type toothbrush display type in its unique design and high-quality brush sanding dual filament tip to the forward bending of the back of hard-depth Brush laniary site, around the teeth close to teeth, dental plaque thoroughly cleaned; arc mitigation brush too much force caused by gingival bleeding and abnormal wear and tear; follow internal alveolar brush with regulation, in-depth teeth cleaning teeth bacteria grouper; display type brush to help clean and dry quickly to curb the breeding of germs.

世界卫生组织大量临床实验证明，产生蛀牙的原因是有害细菌的大量繁殖，功能型牙刷的特色在于其独特展示型刷头设计及优质双尖磨毛细丝，能向前弯曲，深入后排难刷大牙部位，包住牙齿紧贴牙缝，彻底清洁牙菌斑；弧型刷头缓解用力过猛而导致的牙龈出血和异常磨损；跟着牙槽内部排列调节刷头，深入牙缝清洁牙菌斑；展示型刷头，有助于快速清洁和晾干，抑制细菌滋生。

Majority of the four root canals of first maxillary molars showed curvatures at varing degrees in mesiodistal and buccolingual directions, and the second curvatures of them were different too.

上颌第一恒磨牙四个根管在近远中方向、颊舌方向均有不同程度的弯曲，其第二弯曲出现的情况也各不相同。

Radiograph of teeth in buccolingual and mesiodistal directions with 15#~20# reamers in root canals calculated and recorded for both views using Photoshop6.0 by computer.

收集南京地区80例上颌第一恒磨牙，在根管中分别插入15#~20#扩大针，拍摄近远中向和颊舌向X线片，用Photoshop 6.0软件测量分析根管弯曲位置、弯曲方向和弯曲角度。

MB1 root canals of the mesiobuccal root canals in maxillary molars were found obvious curve out by the rate of 82.5% in mesiodistal direction, 77.5% in buccolingual direction and there is no difference of curvature degree in the two directions.

结果：1上颌第一磨牙腭侧根管通畅、较直。2远中颊侧根管在近远中方向有80%，颊舌方向有45%出现大于5的明显弯曲，弯曲位置多位于根中1/3，且近远中向的弯曲明显大于颊舌向(P.05)。3上颌第一恒磨牙近中颊根颊侧根管在近远中方向、颊舌方向分别有82.5%、77.5%出现大于5的明显弯曲。

However, it is not known how orthodontic force influences the function of cementoblast and what is the relationship between the function change of cementoblast with root resorption. So we studied the effect of mechanical stimuli on root resoption by examining the expression OPG and RANKL and exploring the related signal transduction pathway in cementoblast. Methods: Cementoblasts OCCM30 were cultured in DMEM with 10% FBS for 48 hours and starved in DMEM with no FBS for 24 hours, then subjected to mechanical strain by four-point bending system with tension and compression stress at 2000μstrain at 0.5Hz frequency. The flow cytometry was used to examine the cell cycle and proliferation activity after 3h, 6h, 12h, 24h loading respectively. OPG and RANKL mRNA were analysed with real time quantitive RT-PCR after the same loading period as FCM.

本课题利用四点弯曲力学加载系统，采用流式细胞术、实时荧光定量PCR、Western免疫印迹等方法，研究体外培养的成牙骨质细胞株OCCM-30在不同力学环境中增殖活性的变化，以及其表达骨保护素和破骨细胞分化因子的mRNA的变化，探讨应力刺激对成牙骨质细胞表达破骨细胞分化调控蛋白的影响，并通过对应力刺激下成牙骨质细胞分裂原活化蛋白激酶家族中的ERK1/2、P38MAPK活性的变化及其与OPG、RANKL基因表达变化关系的研究，对力学刺激调节破骨细胞分化调控蛋白的相关上游信号转导通路进行初步探讨。

The proportion of maxillary center incisors, maxillary lateral incisors, maxillary canines curved in mesiodistal were 11.17%, 16.19% and 21.43%, in labio-lingual were 39.59%, 40.00% and 29.59%, both in labiolingual and mesiedistal directions were 4.60%, 35.24% and 24.49%.

大约50％左右的上颌前牙根管存在中度弯曲：与上颌切牙相比，上颌尖牙的弯曲度略大而弯曲半径略小。

MB1 root canals of the mesiobuccal root canals in maxillary molars were found obvious curve out by the rate of 82.5% in mesiodistal direction,77.5% in buccoling

上颌第一恒磨牙四个根管在近远中方向、颊舌方向均有不同程度的弯曲，其第二弯曲出现的情况也各不相同。

Oral Surg,1971,32∶271-275［2］ Weine FS,Healy HJ,Gerstein H,et al.Canal configuration in the mesiobuccal root of the maxillary frist molar and its endodontic significance ［J］. Oral Surg Oral Med Oral Pathol,1969,28∶419-425［3］ Weller RN,Hartwell GR.

本研究通过对80例离体上颌第一磨牙行近远中方向，颊舌方向x 线投照，旨在近一步了结其根管的弯曲走向，弯曲程度，弯曲位置。X线片只能反应根管在一个平面上的走向、形态。

Radiograph of teeth in mesiodistal direction were taken.

结果 ：单根单根管上颌第二前磨牙的根管弯曲仅有 2个，单根双根管牙齿的根管明显弯曲有 6个，在 2 8个双根牙中有明显根管弯曲的 6个，根管弯曲的牙齿总发生率为 6 。6 %(14 /2 13)。

Methods: One hundred and twenty teeth with curved root canals were randomly divided into 2 groups: 74 curved root canals in group PT were prepared by ProTaper rotary Nickel-Titanium file with crown-down technique, and 75 curved root canals in group SS were prepared by K-files with step-back technique.

选择2005年6月至12月间本院口腔内科行根管治疗的120例患者（120颗牙），随机分为两组：试验组用ProTaper机用镍钛锉及冠根向预备技术预备弯曲根管74个，对照组用不锈钢K型锉及逐步后退法技术预备弯曲根管75个。

Graf, without question, is the greatest women's player in history.

格拉芙，现在，毫无疑问是女子网坛历史上最伟大的选手。

If not, you will have to look around at all your important data.

如果没有，您将需要检查所有的重要数据。