下颌第二磨牙根管显微镜下根管口分型探讨

目的通过显微镜分析下颌第二磨牙根管口的解剖特点及分型。方法选择患牙髓炎或根尖周炎的下颌第二磨牙653个,根管显微镜下观察并记录根管口形态,对其根管口形态分类计数,计算其出现率。结果下颌第二磨牙单根牙Ⅰ-1型47例(7.20%),Ⅰ-2型65例(9.95%),Ⅰ-3型263例(40.27%),Ⅰ-4型22例(3.37%);C形根管256例(39.21%)。完全C形根管及部分C形根管分别占17.31%、21.90%。结论根管显微镜下可以更好地观察下颌第二磨牙根管口形态,提高C形根管诊断率。根管口形态呈C形根管系统较多,不利于根管的彻底清理和充填。     

下颌第二磨牙C形根管构型及其影响因素的CBCT研究

目的:应用CBCT对下颌第二磨牙C形根管的解剖形态进行评估。方法:根据CBCT影像选取出579例具有下颌第二磨牙C形根管的患者,分别进行对称性、根面沟及不同横断面的根管形态分析。结果:双侧下颌第二磨牙同为C形根管有80.0%;1047颗C形根管在根管口、根中、根尖的根管构型比较差异具有统计学意义(P<0.05);不同性别在根中与根尖的根管构型比较差异有统计学意义(P<0.05);18～25岁组与26～50岁组在3个不同横断面上的根管构型比较差异有统计学意义(P<0.05);具有舌侧沟与具有颊舌侧沟的在不同横断面上的根管构型比较差异有统计学意义(P<0.05)。结论:利用CBCT,可以准确判断下颌第二磨牙C形根管构型及走向,有助于对形态复杂的C形根管进行诊治。     

应用锥形束CT研究下颌第二磨牙根管数目和构型

目的采用锥形束CT（cone-beam computed tomography,CBCT）观察下颌第二磨牙根管数目及构型,为根管治疗提供影像学参考。方法随机调取700颗下颌第二磨牙的CBCT资料,统计下颌第二磨牙牙根数目、根管数目和构型,以及C型根管的发生率。结果下颌第二磨牙c形牙根的发生率为36．O％;2根牙的根管构型：61．1％近中根管为Ⅳ型,96．1％远中根管为I型;C形根管在根管口及根尖1／3处类型变化多。结论下颌第二磨牙牙根和根管解剖形态多样,CBCT清晰的三维影像能为根管治疗提供参考。     

下颌第三磨牙的解剖形态观察

目的：探讨下颌第三磨牙的解剖外形及其根管口的形态特点,为牙体牙髓病的临床治疗提供理论依据.方法：收集临床拔除的下颌第三磨牙159颗,观察牙尖和牙根数目,测量牙体长度、牙冠最大近远中径和最大颊舌径;拍摄颊舌向和近远中向X线初始片;开髓、拔髓、疏通根管,体视显微镜测量各根管口之间的距离.结果：外形上,下颌第三磨牙根长大于冠长,近远中径大于颊舌径.单根居多,占54.09%,其次是两根,占40.51%.下颌第三磨牙的根管数目1～4,以两根管（55.35%）居多.S型根管14例,C型根管36例（22.80%）,其中Ⅰ型50.0%,Ⅱ型36.1%,Ⅲ型13.9%.多根管牙的各根管口之间的距离最小0.35 mm,最大5.00mm;均值2.13～3.95.结论：下颌第三磨牙根管系统较为复杂,可以出现C型、S型及弯曲根管.     

口腔锥形束CT在下颌第二磨牙C形根管诊治中的应用

目的探讨口腔锥形束CT(cone-beam computed tomography,CBCT)在根管治疗中诊断治疗下颌第二磨牙C形根管的临床应用。方法选取初次根管治疗失败的下颌第二磨牙62颗,根尖片不能确定根管解剖形态以及可疑遗漏根管,患牙采用CBCT进行扫描三维重建。结果使用CBCT确定下颌第二磨牙中52颗为C形根管,C形根管发生率达83.87%,C形根管中28颗为C1型变异根管(53.84%),18颗为C2型变异根管(34.62%),6颗为C3型变异根管(11.54%)。52颗患牙除2颗因根管侧穿导致根管治疗失败外,其余50颗患牙通过热牙胶充填与垂直加压技术将软化的牙胶充入不规则的根管系统,达到严密充填根管,根管再治疗后患牙成功治疗的有50颗(96.15%),均无不适症状。CBCT在根管治疗中辅助定位变异根管,定位准确率较高。结论 CBCT影像精密度高,可从三维角度分析根管,在根管治疗中诊断治疗下颌第二磨牙C形根管具有临床指导意义。     

下颌第二磨牙"C"形融合根及其根管形态的观察

目的　观察具有“C”形融合根的离体下颌第二磨牙牙根外形及根管形态。方法　通过牙根水平片切及透明标本的制作 ,观察 4 0颗下颌第二磨牙牙根的形态特点 ,并测量其长度。结果　牙根均在颊侧融合 ,牙根长度较正常牙长且有显著性差异 (P <0 .0 5 )。根管形态变异较多 ,仅 4 0 %呈现根颈到根尖的“C”形 ,3 0 %为“分号”形 ,10 %为“分离”形 ,2 0 %的牙根内各横断面形态可有不同。结论　下颌第二磨牙“C”形融合根的变异较多 ,不利于根管的彻底清理和充填     

C形根管系统的形态、诊断和治疗

C形根管系统是根管横截面呈“C”形的根管系统,常发生于下颌第二恒磨牙。C形根管系统的横截面形态从根管口到根尖可发生明显变化。C形根管系统的术前诊断、牙髓摘除、根管预备、根管充填以及桩腔预备和修复较常规情况更为困难。手术显微镜的应用可提高C形根管系统的诊断和治疗成功率。     

13例下颌前磨牙C形根管的锥束CT分析

目的：采用锥束CT（CBCT）分析下颌前磨牙C形根管形态。方法：选取13例22个下颌前磨牙C形根管患者的CBCT数据,使用NNT软件分析下颌前磨牙C形根管的形态、根面沟、根管分叉和双侧根管对称性。结果：下颌第一前磨牙根管C1型为23.8%、C2型61.9%、C3型14.3%,下颌第二前磨牙1例C3型。61.9%的下颌第一前磨牙C形根管在根中1/3分叉,下颌第二前磨牙在根冠1/3处根管分叉。下颌第一前磨牙C形根管对称率为61.5%,下颌第二前磨牙无对称性发生。结论：下颌前磨牙C形根管解剖结构复杂,CBCT可准确研究根管系统。     

C形根管系统的形态、诊断和治疗

C形根管系统是根管横截面呈“C”形的根管系统，常发生于下颌第二恒磨牙。C形根管系统的横截面形态从根管口到根尖可发生明显变化。C形根管系统的术前诊断、牙髓摘除、根管预备、根管充填以及桩腔预备和修复较常规情况更为困难。手术显徽镜的应用可提高C形根管系统的诊断和治疗成功率。     

新疆维吾尔族成人下颌第一前磨牙根管的形态分析

目的:采用锥形束CT探讨新疆维吾尔族成人双侧下颌第一前磨牙根管的解剖形态。方法:选100例双侧下颌第一前磨牙的CBCT扫描数据,分析其根管数目及形态、双侧根管对称性、两根管口间的距离和多根管分叉位置,以Vertucci根管分型为标准对根管形态进行分型。结果:下颌第一前磨牙不同根管类型发生率分别为Ⅰ型76.5%,Ⅳ型8.5%,Ⅱ型6%,Ⅴ型4%,Ⅲ型3.5%,C形1.5%;两根管口间距离集中在1~3 mm,根管双侧对称性为85%。下颌第一前磨牙多根管发生率与性别有相关性(P=0.02),而左、右两侧下颌第一前磨牙多根管发生率无差异。结论:下颌第一前磨牙根管解剖结构复杂,多根管发生率超过20%,CBCT可为根管系统提供准确依据。     

C-shaped root canals in mandibular second molars in a Chinese population

Abstract The purpose of this investigation was to study the prevalence of C-shaped roots, root canal orifices, and root canals in the mandibular second molars of a Chinese population. A total of 581 second mandibular molars were collected in Hong Kong and Taiwan. The teeth were demineralized and placed in methyl salicylate to induce transparency. The pulp chamber floor was examined to ascertain the number of root canal orifices. Chinese ink was then injected into the root canal system to demonstrate the root canal anatomy. The mandibular second molars had separate roots in 66.4%, cone-shaped roots in 2.1% and C-shaped roots in 31.5%. The C-shaped roots had C-shaped canal orifices in 68.3% (21.5% of whole material). True C-shaped root canals were observed in 65.8% of the teeth with C-shaped orifices and in 13.9% of the whole material. Separate root canals were seen in 34.2% of the teeth with C-shaped orifices. Separate canal orifices were found in 31.7% of the C-shaped roots and 7.4% of these roots had true C-shaped canals. In the whole material 0.9% of the roots with individual canal orifices had C-shaped canals. In conclusion, C-shaped root canals were common in mandibular second molars in the Chinese subjects studied. The C-shaped root canals were often, but not always recognized because of a C-shaped canal orifice.     

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目的观察下颌第二磨牙牙根、牙根不同部位根管数目及形态,为根管治疗提供依据。方法选取2006年1月至2008年4月首都医科大学附属北京中医医院口腔科门诊中因各种原因拔除的下颌第二磨牙166颗,观察牙根数目及形态后,将牙根切为根上1/3,根中1/3和根尖1/3。观察不同部位的根管数目及形态。结果下颌第二磨牙单根12颗(7.2),双根101颗(60.8),其中近中根1-1型根管48颗(47.5),2-1型30颗(29.7),1-2型18颗(17.8),2-2型5颗(5)。远中根1-1型根管88颗(87.1),2-1型2颗(2.0),1-2型4颗(4.0),2-2型7颗(6.9)。C形根53颗(32.0),其中只有26颗具有C形根管(49)。166颗患牙中C形根管的总检出率为15.7。结论下颌第二磨牙牙根及根管数目、形态变异较多,C形根管的存在给根管治疗带来困难,不利于根管的彻底清理和充填。     

The root and root canal anatomy of maxillary molars in a Chinese population

Abstract The purpose of this investigation was to study the prevalence of fused roots, C-shaped roots, C-shaped root canal orifices and C-shaped root canals in the maxillary molars of a Chinese population. A total of 305 first molars and 309 second molars were collected in Taiwan. The teeth were demineralized and placed in methyl salicylate to make them transparent. Root fusion was examined and the pulp chamber floor was checked for C-shaped orifices. Chinese ink was then injected into the root canal system to demonstrate possible C-shaped canals. The maxillary first molars had the palatal root fused with the mesiobuccal root in 0.3% of the cases, and with the distobuccal root in 2.0%. Teeth with C-shaped roots existed in only 0.3% of maxillary first molars, while 6.2% of the maxillary first molars and 40.1% of the maxillary second molars had fused roots. The maxillary second molars had the palatal root fused with the mesiobuccal root in 18.1% and with the distobuccal root in 2.6%; the palatal root was fused with the mesiobuccal and distobuccal root in 8.1% of the material. The maxillary second molars had a C-shaped root in 4.5% and C-shaped root canal orifices with C-shaped root canals in 4.9% of the cases. Fused roots or incompletely separated roots are common in the maxillary second molars amongst Chinese people, while C-shaped roots and root canals in maxillary molars are not frequently seen.     

C-shaped root canal in a maxillary first molar: a case report

AIM: This case report presents an unusual C-shaped root canal system in a maxillary first molar tooth. SUMMARY: Although C-shaped root canals are most frequently seen in the mandibular second molar, they may also appear in maxillary molars. A literature search revealed only a few case reports of C-shaped root canal systems in maxillary molars. The present case describes a C-shaped canal in the buccal root of a maxillary first molar. The endodontic access cavity displayed two canal orifices, one leading to the canal system in the buccal root, the other into the palatal root canal system. In the buccal root, what appeared to be the mesial and distal canals joined to form a single C-shaped canal. KEY LEARNING POINTS:--Careful examination of radiographs and the internal anatomy of teeth is essential.-- The location and morphology of root canals should be identified at high magnification under the microscope.     

显微CT法研究上颌第一磨牙根管系统解剖形态

目的 使用显微CT研究上颌第一磨牙根管系统解剖形态.方法 随机收集33颗上颌第一磨牙,使用显微CT扫描后重建根管系统.观察并记录各牙根根管形态和分支根管的发生数目、位置.记录各根管口位置并测量根管口间的距离和所成角度.在距离根尖1、2和3mm处进行虚拟切割,记录断面上分支根管暴露情况.结果 上颌第一磨牙近颊根第二根管发生率为75.76%.近颊根发生分支根管为71.64%;近颊根分支根管发生率为72.73%.91.04%的分支根管发生于根尖1/3段,近颊根距根尖3mm处截面分支根管暴露率为12.12%.近颊根第一、第二根管口间的距离为(1.60±0.41)mm.结论 上颌第一磨牙根管系统解剖形态复杂,近颊根根管形态存在较大解剖变异.     

下颌第二磨牙C形根管的临床诊断和治疗

目的：探讨下颌第二磨牙C形根管的临床诊断和治疗。方法：选择需进行治疗的下颌第二磨牙104个,通过术前拍摄X线片和术中根管显微镜下髓腔探查,按照AL-Fouzan术前X线诊断标准和Melton分类标准分别诊断是否为C形根管。采用手用Protaper进行根管预备,热牙胶垂直加压技术充填根管。记录C形根管口的类型,统计两种方法诊断的成功率。根据治疗前、中、后的X线评价根管预备和充填的效果,3～6个月后复查。结果：下颌第二磨牙C形根管术前X线片和根管显微镜的诊断率分别为72.1%和90.7%,所有患牙均无根管内并发症发生,治疗效果好。结论：术前X线片和根管显微镜相结合大大提高了下颌第二磨牙C形根的诊断率,镍钛器械预备根管和热牙胶垂直加压技术充填根管可获得良好的治疗效果。     

下颌第二恒磨牙牙根及根管形态的锥形束CT研究

目的 使用锥形束CT扫描评估下颌第二恒磨牙牙根和根管解剖形态.方法 收集354例患者双侧下颌第二恒磨牙的锥形束CT图像,统计下颌第二恒磨牙牙根数目、根管数目和构型,以及C形根管的发生率.结果 下颌第二恒磨牙以双根最多,发生率为57.34%,C形根的发生率为38.28%;双根者近中根多为2-2型(80.54%),远中根多为1-1型(96.06%);C形根管的发生率为25.99%,左、右下颌的发生率没有统计学差异(P>0.05).结论 下颌第二恒磨牙牙根和根管解剖形态复杂多样,锥形束CT能为根管治疗提供参考.     

下颌第二磨牙扇形根管的出现率与牙根形态的关系

目的：调查下颌第二磨牙扇形根管的出现率与牙根形态的关系。方法：通过进行根管治疗的202个下颌第二磨牙的临床检查，对其牙根形态和根管形态分类计数，调查扇形根管的出现率。结果：分叉根的扇形根管出现率为18．7％，平行根为35．5％，锥形根为76．3％。结论：近中根与远中根相距越近，扇形根管的出现率越高。