上颌第二乳磨牙近中颊根第二根管的临床研究

目的:研究上颌第二乳磨牙近中颊根第二根管(Second mesiobuccal root canal,MB2)的临床发现率。方法:探查近中颊根根管口与腭根根管口之间的发育沟或暗线,研究上颌第二乳磨牙MB2的临床发现率。结果:54例患者共56颗上颌第二乳磨牙,其中有26颗存在MB2,发现率为46.43%。临床发现率在性别及牙位中无显著性差异。结论:上颌第二乳磨牙中MB2有较高的发现率,临床上应注意探查以免遗漏。     

上颌第一磨牙近中颊根的研究进展

上颌第一恒磨牙位于牙弓后段,髓腔解剖结构复杂,根管治疗难度大,其根管治疗的失败往往由于近中颊根第二根管(MB2)的漏治引起[1]。因此,了解上颌第一磨牙近中颊根根管系统的复杂性是根管治疗成功的关键[2-4]。目前国内外已有许多关于上颌第一磨牙近中颊侧根管根管形态学的体内外研究[5-9],本文就其研究进展综述如下。     

上颌磨牙近中颊根管间峡区及其在牙髓显微外科手术中的意义

目的 研究离体上颌磨牙近中颊根的管间峡区分布情况，并讨论其在牙髓显微外科手术中的临床意义。方法 收集离体上颌第一、二磨牙275颗，横切近中颊根，记录各截面的根管数和管间峡区分布情况。结果 近中颊根双根管率在上颌第一磨牙和第二磨牙分别为88．89％和54．04％；管间峡区在距根尖3～5mm水平出现率最高，4mm水平率近100％。结论 使用手术显微镜和牙髓显微外科手术，可提高管间峡区的出现率，从而提高上颌磨牙牙髓外科手术成功率。     

上颌第一前磨牙三根管的临床检诊率

目的:探讨上颌第一前磨牙三根管的临床检诊率以及根管显微镜在提高上颌第一前磨牙根管临床检诊中的作用。方法:选取进行常规根管治疗181颗上颌第一前磨牙,以及进行显微根管治疗的184颗上颌第一磨牙,每一病例均拍摄术前X线片,探查根管,并记录根管数目。结果:进行常规根管治疗和显微根管治疗的上颌第一前磨牙检出率分别为0.6%和4.3%,对上颌第一前磨牙常规根管治疗和显微根管治疗的三根管检测进行卡方检验,后者的检出率明显高于前者(P<0.001)。结论:根管显微镜有助于提高上颌第一前磨牙三根管的临床检诊,选择显微根管治疗有助于提升上颌磨牙根管治疗的成功率。     

治疗上颌第二磨牙四根管一例体会

根管治疗的目标是清除根管内感染物质,严密封闭根管,促进根尖病变愈合。根管预备不良、消毒的不充分、充填不适、遗漏根管是根管治疗失败的主要原因。因此,根管解剖知识的掌握程度和对根管变异的预先估计能力的提高可以大大降低这类原因造成的根管治疗的失败。笔者近期接诊1例上颌第二磨牙四根管病例,现报道如下。     

Micro-CT应用于口腔治疗的初步研究

目的:研究微CT(micro-computed tomography,Micro-CT)扫描与常规CT(Computer Tomography)扫描人磨牙图像的差距,探讨Micro-CT在研究上颌磨牙近中颊根第二根管(second mesiobuccal canal,MB2)根管口的位置及其与其他根管口的位置关系中的作用,为今后Micro-CT应用于口腔医学领域的基础。方法:应用Micro-CT扫描牙齿,将所得到的图像与螺旋CT扫描得到的图像分段进行直观比较,观察Micro-CT的图像结果,将找到上颌磨牙近中颊根第二根管的牙齿进行分析。结果:Micro-CT图像结果分层细密,边界清晰,根管显影清晰,从髓腔至根尖都有良好的根管影像。并且可以准确的定位上颌磨牙近中颊根第二根管。结论:用Micro-CT扫描的牙齿图像边界清晰,符合实际情况,有助于临床医生更好的发现与治疗上颌磨牙近中颊根第二根管,使根管治疗更加完善。能正确地反映所需要研究的临床问题,应用前景广阔。     

下颌第二磨牙C形根管发生率的研究

目的：研究下颌第二磨牙C形根管系统的发生率。方法：选择年满18周岁本国患者的下颌第二磨牙为研究对象,通过锥形束CT（cone beam CT,CBCT）扫描,然后在矢状面、冠状面、横断面等多层面重建三维数据图像。根据C形根管系统的解剖学特征判断其发生率。结果：纳入本研究的共有124名患者（156颗下颌第二磨牙）。其中,具有C形根管系统的有66颗,发生率为42.3%。结论：C形根管系统在下颌第二磨牙中具有较高的发生率;CBCT在下颌第二磨牙C形根管治疗过程中,能为临床医师提供更直观、更准确的影像学依据。     

基于 CBCT 评价的下颌第二磨牙牙根和根管解剖形态分析

目的 分析CBCT对下颌第二磨牙牙根和根管解剖形态的评价价值。方法 选取2020年5月-2022年 5月于我院接受CBCT影像检查的患者610例，回顾性分析610例患者下颌第二恒磨牙牙根和根管形态及分 布情况、356例患者非C型根下颌第二恒磨牙牙根数目、根管数目及分布情况，以及312例患者双根下颌第 二恒磨牙根管构型分布情况。结果 左下颌和右下颌、男性和女性下颌牙根形态比较，差异无统计学意义 （ P ＞0.05）；左下颌和右下颌、男性和女性C型根管检出率比较，差异无统计学意义（ P ＞0.05）；左下颌 和右下颌、男性和女性牙根数比较，差异无统计学意义（ P ＞0.05）；左下颌和右下颌、男性和女性根管数 比较，差异无统计学意义（ P ＞0.05）；男性和女性根管构型比较，差异无统计学意义（ P ＞0.05）；近中 根中，Ⅳ型，2-2检出率高于Ⅰ型，1（ P ＜0.05）；Ⅰ型，1检出率高于Ⅱ型，2-1（ P ＜0.05）；Ⅱ型，2-1 检出率高于Ⅴ型，1-2、Ⅲ型，1-2-1、2-1-2型、2-3-2型（ P ＜0.05）；远中根中，Ⅰ型，1检出率高于Ⅳ 型，2-2（ P ＜0.05）；Ⅳ型，2-2检出率高于Ⅱ型，2-1（ P ＜0.05）。结论 CBCT对下颌第二磨牙牙根和根 管解剖形态的评价价值较高，下颌第二恒磨牙主要为融合根或双根，具有较高的C型牙根与根管发生率。     

正畸拔除下颌第二前磨牙和第一磨牙对第三磨牙的影响

目的:比较青年正畸治疗患者拔除下颌第二前磨牙和下颌第一磨牙对下颌第三磨牙萌出的影响。方法:回顾68例伴随下颌第三磨牙阻生的安氏Ⅰ类青年正畸患者,分别设计不拔牙、拔除下颌第二双尖牙、拔除下颌第一磨牙,采用直丝弓矫治器,闭合曲法关闭拔牙间隙,应用曲面断层片分析三组患者正畸治疗前后下颌第三磨牙倾角和萌出间隙的变化,结果采用t检验统计分析。结果:非拔牙组治疗前后左右下颌第三磨牙倾角(RM3\LM3)、左右下颌第三磨牙萌出间隙(RS\LS)、左右下颌第三磨牙萌出间隙和牙冠宽度比率(Rratio\Lratio)改变无统计学意义(P>0.05);拔除下颌第二前磨牙组RM3、LM3变化无统计学意义(P>0.05);RS、LS、Rratio、Lratio变化有统计学意义(P<0.05);拔除下颌第一磨牙组RM3、LM3变化无统计学意义(P>0.05);其RS、LS、Rratio、Lratio变化有显著的统计学意义(P<0.01)。结论:拔牙矫治有助于下颌第三磨牙萌出间隙的增加,拔除下颌第一磨牙较拔除下颌第二前磨牙产生更显著的下颌第三磨牙后间隙改变,但青年患者拔牙矫治对下颌第三磨牙倾角无明显影响。     

不同方法治疗近中阻生大学生第二或三磨牙远中龋齿的疗效分析

目的:评价不同方法治疗近中阻生学生第二或三磨牙远中龋齿的临床效果。方法:采用多阶段抽样法从沧州市各高校名册随机抽取2500名在校学生,并采用问卷调查和口腔检查获取学生基本信息、口腔知识掌握情况和口腔资料。根据阻生智齿牙长轴方向和口腔诊断结果,将发生近中阻生智齿且第二、三磨牙远中龋齿,以及未达到诊疗标准的学生分别纳入拔牙组、移植组和对照组,分别行常规微创拔牙手术治疗、拔除第二磨牙移植第三磨牙干预和健康教育。干预后1个月、3个月、6个月、12个月进行随访,比较分析三组干预方案的预后差异。结果:抽取的2500名大学生中共有2060名大学完成问卷调查并接受口腔检查,问卷有效率为82.40%;下颌智齿检出率为67.84%。近中阻生组发生第二、三磨牙龋齿550例,其中男248例,女302例;完成全程随访的共26名,年龄平均(21±2)岁,其中男生12名,女生14名,男女比为6:7。男生第二、三磨牙龋齿率为12.90%,低于女生的29.47%(P<0.05);不同年龄、学历的学生龋齿率的差异无统计学意义(P>0.05);知晓口腔知识学生龋齿率低于不知晓的(P<0.05)。拔牙后症状较拔牙前缓解(χ2=6.138,P<0.05);移植后症状缓解较移植前明显缓解(χ^2=55.881,P<0.01);对照组护牙知识健康教育前后差异无统计学意义(χ^2=0.678,P>0.05)。不同性别学生接受牙移植术后牙位、牙稳固程度、牙周炎症、牙根吸收、叩痛感和牙功能的随访得分随着时间的增加而增加,其中女生的术后牙位、牙周炎症、牙根吸收和牙功能改善的幅度均较男生大(P<0.01)。结论:智齿知识和护牙常识知晓率偏低,拔牙法和移植法均能不同程度上解决近中阻生第二或三磨牙远中龋齿问题,其中第二磨牙龋齿应用移植法治疗的学生恢复情况较好,且经济实惠。     

Detection of a second mesiobuccal canal in the mesiobuccal roots of maxillary first molar teeth.

OBJECTIVE: The aim of the present study was to determine whether the MB2 canal in the mesiobuccal root (MBR) of maxillary first molars could be identified through a clinical access cavity preparation, with and without magnification. STUDY DESIGN: One hundred extracted maxillary first molar teeth were collected. After a clinical access cavity preparation with careful use of bur to locate any additional canal (dentine troughing), the MB2 canals were located in 2 stages. Stage I was located with unaided vision and stage II was located under moderate magnification with x3.5 magnifying dental loupes. All specimens were stained, rendered transparent, and then classified. The number of canals detected by stage was analyzed statistically by a chi-square test. Statistical significance was considered to be P < or = .05. RESULTS: Under magnification, the number of detected MB2 canals was increased from 55 (56.7%) to 61 (62.9%) teeth. Cleared teeth showed 77.32% of MB2 canals. The effectiveness of MB2 location was 73.3% and 82.7% in stage I and stage II, respectively. There was no statistically significant difference between the 2 methods of detecting the MB2 canal (P = .3). CONCLUSIONS: The use of magnification enhanced the ability to detect the MB2 canals, although the difference was not statistically significant. The MB2 canals could not be detected in 16.5% of the teeth, mainly because of pulpal calcification.     

Single-site access robot-assisted epicardial mapping with a snake robot: preparation and first clinical experience

CardioARM, a highly flexible “snakelike” medical robotic system (Medrobotics, Raynham, MA), has been developed to allow physicians to view, access, and perform complex procedures intrapericardially on the beating heart through a single-access port. Transthoracic epicardial catheter mapping and ablation has emerged as a strategy to treat arrhythmias, particularly ventricular arrhythmias, originating from the epicardial surface. The aim of our investigation was to determine whether the CardioARM could be used to diagnose and treat ventricular tachycardia (VT) of epicardial origin. Animal and clinical studies of the CardioARM flexible robot were performed in hybrid surgical–electrophysiology settings. In a porcine model study, single-port pericardial access, navigation, mapping, and ablation were performed in nine animals. The device was then used in a small, single-center feasibility clinical study. Three patients, all with drug-refractory VT and multiple failed endocardial ablation attempts, underwent epicardial mapping with the flexible robot. In all nine animals, navigation, mapping, and ablation were successful without hemodynamic compromise. In the human study, all three patients demonstrated a favorable safety profile, with no major adverse events through a 30-day follow-up. Two cases achieved technical success, in which an electroanatomic map of the epicardial ventricle surface was created; in the third case, blood obscured visualization. These results, although based on a limited number of experimental animals and patients, show promise and suggest that further clinical investigation on the use of the flexible robot in patients requiring epicardial mapping of VT is warranted.     

Effects of imaging system and exposure on accurate detection of the second mesio-buccal canal in maxillary molar teeth.

OBJECTIVES: The objectives of this study were to determine observer ability to detect the second mesio-buccal canal (MB2) in maxillary molars using analog film, CMOS, and photostimulable phosphor x-ray detectors across a wide range of radiation exposures and to determine the optimal exposures for these modalities accurately detecting presence of the MB2. RESEARCH DESIGN: Using 6 experimental models with 2 maxillary molars in each, images were generated with the 3 detector modalities at nominal x-ray beam angulations of 0 degrees and 10 degrees across a range of radiation exposures. Observers independently assessed presence of the MB2 in images presented in random order. Horizontal root sections were then evaluated to determine true MB2 presence. RESULTS: For single images at optimal exposures, the correct number of mesiobuccal canals could be identified 55% of the time for CMOS (RVG 6000), 44% of the time for analog x-ray film (InSight), and 39% of the time for photostimulable phosphor (DenOptix). Statistically significant differences were observed between the imaging modalities (chi2 = 23.4, crucial value = 5.99, P < or = .05). RVG 6000 CMOS outperformed both DenOptix photostimulable phosphor (z score = -5.5) and InSight analog direct exposure x-ray film (z score = 4). Exposure affected the rate of accuracy for MB2 detection across the exposure range tested for RVG 6000 and for film, but not to any appreciable degree for DenOptix. CONCLUSIONS: The CMOS detector (RVG-6000) performed best for evaluating presence of the MB2. This was the only modality to exceed 50% reliability with optimal exposure when single images were considered.     

Clinical accuracy evaluation of femoral canal preparation using the ROBODOC system

The purpose of this study was to evaluate the clinical accuracy of femoral canal preparation using postoperative reconstructed computed tomography (CT) images of 75 consecutive total hip arthroplasties performed with a two-pin-based ROBODOC system. Intraoperatively, the robot milled the femoral canal according to the preoperative planning performed with preoperative CT data and the ROBODOC workstation. Postoperative CT data was obtained 1 month postoperatively. Anteroposterior and lateral synthetic radiographs and axial images were reconstructed from CT data on the workstation. The mean difference between the preoperative planning and the postoperative CT images was less than 5% in canal fill, less than 1mm in gap, and less than 1° in the mediolateral and anteroposterior alignment. Clinical femoral canal preparation using the ROBODOC system results in a high degree of accuracy.     

(足母)趾、第2足趾供血系统的彩超检测及临床应用

目的获得邰趾、第2趾供血系统彩超检查的资料,探讨临床应用价值。方法利用彩超对正常人100只足的足背动脉、第一跖背动脉、第一跖底动脉进行超声探测并给予分型,临床应用26例,证实其可靠性、实用性。结果足背动脉内径(2.00±0.44)mm,按其口径可分为粗大型、中间型、纤细型,出现率分别为46%、52%、1%;第一跖背动脉起始处距皮肤距离(9.12±3.10)mm,中点距皮肤距离(7.14±2.34)mm,中点处内径(1.17±0.36)mm,按第一背侧骨间肌的关系可分为浅表型、肌内型、肌下型,出现率分别为46%、45%、7%,按口径可分为粗大型、中间型、纤细型,出现率分别为15%、69%、4%;第一跖底动脉出现率为92%,口径与第一跖背动脉有互补关系。临床应用26例,术中探查情况与术前彩超检查完全吻合,对血管变异病例行相应处理,再造38指均成活。结论彩超对邰趾、第2趾供血系统的检查结果与解剖学资料相似,是准确、可信、可靠的,术前应用可对手术方案的制定、判断手术的难易程度、指导术中操作等有重要意义。     

Mu趾、第2足趾供血系统的彩超检测及临床应用

目的获得(足母)趾、第2趾供血系统彩超检查的资料,探讨临床应用价值.方法利用彩超对正常人100只足的足背动脉、第一跖背动脉、第一跖底动脉进行超声探测并给予分型,临床应用26例,证实其可靠性、实用性.结果足背动脉内径(2.00±0.44)mm,按其口径可分为粗大型、中间型、纤细型,出现率分别为46%、52%、1%;第一跖背动脉起始处距皮肤距离(9.12±3.10)mm,中点距皮肤距离(7.14±2.34)mm,中点处内径(1.17±0.36)mm,按第一背侧骨间肌的关系可分为浅表型、肌内型、肌下型,出现率分别为46%、45%、7%,按口径可分为粗大型、中间型、纤细型,出现率分别为15%、69%、4%;第一跖底动脉出现率为92%,口径与第一跖背动脉有互补关系.临床应用26例,术中探查情况与术前彩超检查完全吻合,对血管变异病例行相应处理,再造38指均成活.结论彩超对( )趾、第2趾供血系统的检查结果与解剖学资料相似,是准确、可信、可靠的,术前应用可对手术方案的制定、判断手术的难易程度、指导术中操作等有重要意义.