显微CT法研究中国人上颌第一前磨牙分支根管形态

目的:使用显微CT扫描法研究中国人离体上颌第一前磨牙分支根管解剖形态。方法:收集63颗中国人上颌第一前磨牙,使用显微CT扫描并构建根管系统三维可视化模型。观察并记录分支根管、根尖三角区发生情况,分析分支根管发生率、分布和开口特征。结果:共有50颗上颌第一前磨牙含有分支根管,发生率为79.37%。共记录到124个分支根管,其中95.16%发生于根尖1/3。分支根管开口于近中和远中方向的分别为33.06%和23.39%。根尖三角区的发生率为7.94%。结论:上颌第一前磨牙分支根管发生率高,根管系统形态复杂,了解其分支根管发生规律对于提高根管治疗成功率具有重要意义。     

下颌第一前磨牙非单根管系统的形态学研究

目的：采用锥形束CT（CBCT）分析下颌第一前磨牙非单根管系统的解剖形态。方法：选取20颗具有非单根管系统下颌第一前磨牙离体牙标本,CBCT 扫描数据,使用三维重建软件分析下颌第一前磨牙牙根的数目、根面沟情况及根管形态。结果：20颗下颌第一前磨牙非单根管系统中,单根及融合单根17颗（85．0％）、双根3颗（15．0％）。根面沟发生率为95．0％,好发于近中舌侧、舌侧。根管形态发生率分别为双根管Ⅲ型（1－2－1）25．0％、Ⅴ型（1－2）5．0％,三根管Ⅷ型（3－3）15．0％、Ⅸ型（3－4）型5．0％、C形9例45．0％、环形1例5．0％,其中C形发生率最高。结论：下颌第一前磨牙非单根管系统解剖形态复杂。     

显微CT法研究中国人下颌切牙根管系统解剖形态

目的:使用显微CT扫描技术研究中国人离体下颌切牙根管系统解剖形态。方法:收集108颗中国人下颌切牙,使用显微CT进行扫描后构建根管系统三维可视化模型。对主根管形态进行分型,记录第二根管分出位置,分支根管的发生率和位置。结果:下颌切牙根管最常见的形态为VertucciⅠ型和Ⅲ型,发生率分别为78.70%和14.81%,分支根管发生率为24.07%。第二根管发出位置在釉质牙骨质界根方(6.07±3.42) mm。结论:下颌切牙根管系统解剖形态复杂,了解其主根管及分支根管的发生规律对于提高根管治疗成功率具有重要意义。     

下颌前磨牙牙根形态和根管系统的锥形束CT研究

目的采用锥形束CT(Cone-beam computed tomography,CBCT)研究下颌前磨牙牙根及根管系统解剖形态特征。方法回顾148例患者288颗下颌第一前磨牙和218颗下颌第二前磨牙的CBCT影像,分析牙根和根管系统形态,采用Vertucci等提出的分类法对根管构型进行分类。结果 288颗下颌第一前磨牙单根牙285颗,双根牙2颗。三根牙1颗;根管Ⅰ型占77.78%,Ⅱ型0.34%,Ⅲ型2.08%,Ⅳ型0.69%,Ⅴ型14.58%,Ⅶ型1.04%,Ⅹ型0.69%,C型2.78%。218颗下颌第二前磨牙全部为单根;根管Ⅰ型占98.17%,Ⅴ型占1.83%。结论下颌前磨牙大多数是单根单根管。下颌第一前磨牙根管系统具有较大的变异性。下颌第一前磨牙多根管类型主要是Ⅴ型,C型根管的检出率也较高。而下颌第二前磨牙多根管的发生率远低于下颌第一前磨牙。多根管的分歧发生在根中或根尖1/3处。CBCT可用于下颌前磨牙复杂根管形态的评价。     

下颌第一前磨牙根管峡部的显微CT研究

目的:运用显微CT研究非单根管的下颌第一前磨牙根尖0～6 mm区域根管峡部出现的位置和发生率,为提高根管治疗和根尖外科手术的成功率提供解剖学依据。方法:从147颗下颌第一前磨牙中挑选出非单根管的40颗,用显微CT以15μm分辨率、30μm层厚扫描及软件三维重建,观察并记录根尖0～6 mm区域各横截面的峡部形态及分布情况,并对根管系统的解剖形态三维重建后,进行二维、三维图像分析。结果:非单根管的下颌第一前磨牙距根尖0～6 mm区域内根管峡部的发生率(%)由根方向冠方以每1 mm为间距依次为:6%、18.5%、78.6%、80%、79.2%、72.5%。结论:非单根管下颌第一前磨牙根管峡部在距根尖3～6 mm区域高发,其中距根尖3～4 mm区域发生率最高。     

不同投照角度X线根尖片诊断下颌前牙、前磨牙多根管的临床评价

目的 探讨不同角度X线投照技术对发现下颌前牙、前磨牙多根管及提高其临床治疗率的作用。方法 选取临床上需要进行下颌前牙、前磨牙根管治疗的患者214例，共247颗患牙。每颗患牙均需拍摄术前X线正、偏位投照片及诊断丝X线正、偏位投照片。依据两种X线影像特点（根管位置和走向不在牙根中心、较粗大的根管在根管上1／3、中1／3突然消失或模糊）判断是否为可疑多根管。采用冠向下法预备，冷侧压法根管充填后将根管分为Ⅰ～Ⅴ型并与X线结果对应。结果 在87颗X线诊断的多根管患牙中，临床证实多根管为60．92％；26．44％为扁根管。诊断丝X线偏位投照片的多根管X线诊断灵敏度为93．0％，4例术后发现有遗漏根管。247颗下颌前牙、前磨牙临床治疗多根管57颗，多根管临床治疗率分别为：中切牙9．43％、侧切牙38．33％、尖牙15．90％、第一前磨牙加．38％、第二前磨牙2．63％。结论 不同角度的术前及诊断丝X线根尖片有助于临床医师发现下颌前牙、前磨牙多根管，其中以诊断丝X线偏位投照发现的多根管最多。     

多根管下颌前磨牙显微根管治疗的效果观察

目的观察下颌前磨牙多根管的发现率以及显微根管治疗方法处理多根管下颌前磨牙的临床疗效。方法选取152颗需进行根管治疗的下颌前磨牙，拍摄术前X线正位投照片和偏位投照片。对单根管患牙采用常规根管治疗，对怀疑多根管的患牙先常规探查根管，再在显微镜下探查并疏通根管，镍钛机动器械预备根管，垂直加压充填技术充填根管。记录根管类型，使用和未使用显微镜时多根管的发现率，根据术前、术中及术后X线片评价根管预备和充填效果。结果下颌第一前磨牙、第二前磨牙多根管的发现率分别为32．9％、7．5％；使用显微镜多根管的发现率高于未使用显微镜者；治疗中无根管堵塞、偏移、台阶、器械折断等并发症发生，完成治疗的31颗多根管下颌前磨牙30颗适充，1颗超充。结论显微根管治疗是处理多根管下颌前磨牙的有效方法。     

老年人下颌磨牙牙根及根管的锥形束CT研究

目的：利用锥形束CT观察分析老年人下颌磨牙的牙根、根管数目和形态。方法：选择能够配合检查,并在扫描过程中头部保持静止状况的老年人,对其牙齿进行锥形束CT扫描,对扫描图像进行三维重建和选择不同方向的断层观察记录下颌磨牙的牙根和根管。结果：锤形束CT检查老年人166例,下颌磨牙共532颗。下颌磨牙近中根均为单根,远中双根仅发生于下颌第一磨牙,而C形根则仅发生于第二磨牙。近中根以两根管为主在下颌第一磨牙和第二磨牙分别占有95．26％和50．38％;远中根以一根管为主在第一磨牙和第二磨牙分别占有64．60％和56．97％,C形根管的发生率为22．48％。结论：下颌磨牙牙根和根管的变化主要发生在第一磨牙的远中根和第二磨牙的C形根及C形根管。     

显微CT与数字成像系统观察下颌第一前磨牙根管形态的比较研究

目的采用显微CT与数字成像系统（RVG）观察下颌第一前磨牙根管形态,比较2种方法对根管分型结果的一致性。方法随机选取根尖发育完全、牙根完整、未进行过牙髓治疗的离体下颌第一前磨牙100颗,拍摄颊舌向和近远中向RVG数字影像（RVG法）,并采用显微CT进行扫描和三维重建（显微CT法）,以Vertucci根管分型为标准对下颌第一前磨牙根管进行分型,并对2种方法的结果进行一致性分析。结果显微CT法发现：下颌第一前磨牙根管中,Ⅰ型67%,Ⅲ型3%,Ⅴ型18%,Ⅶ型2%,其他类型10%;RVG法发现：Ⅰ型71%,Ⅲ型2%,Ⅴ型23%,Ⅶ型1%,其他类型3%。显微CT法和RVG法同时判读为单根管和复杂根管的比率分别为63%、25%。2种方法分型结果间的Kappa值为0.541,为中度一致。82.8%的含根面沟的下颌第一前磨牙有2个或2个以上的根管。结论数字成像系统基本能反映离体下颌第一前磨牙根管类型,但对复杂根管分型准确性较差;显微CT三维影像能清晰、准确地显示离体下颌第一前磨牙根管形态。     

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。     

多根管下颌第一前磨牙根管形态的显微CT分析

目的: 采用显微CT技术扫描并三维重建多根管下颌第一前磨牙根管系统,分析其解剖特点。方法: 收集32例多根管离体下颌第一前磨牙,采用显微CT扫描并三维重建,分析根管数目、形态、分叉位置及5种细微结构（侧支根管、根尖分歧、峡部、袢形结构、根尖三角区）并进行统计。结果: 32例下颌第一前磨牙中,96.88%含有根面凹陷（沟）,Vertucci分型中Ⅱ型、Ⅲ型、Ⅴ型均为3.12%,Ⅳ型31.25%,Ⅷ型9.38%,Ⅸ型15.62%,C形34.38%;62.50%的根管分叉于根中1/3,37.50%分叉于根尖1/3。细微结构中,侧支根管占56.25%,根尖分歧占43.75%,峡部占40.62%,袢形结构占21.88%,根尖三角区占6.25%。侧支根管在根管不同位置均可见,其余都发生于根中1/3和根尖1/3。结论: 多根管下颌第一前磨牙多含有根面凹陷（沟）,根管系统结构复杂,显微CT三维重建可清晰、准确地显示其根管形态。     

离体下颌前磨牙根管及牙根形态研究

目的 :研究离体下颌前磨牙的牙根及根管形态。方法 :观察并记录 69个离体下颌第一前磨牙及 93个下颌第二前磨牙牙根的基本形态 ,对牙齿进行近远中向X线摄片 ,当X线片上显示疑问根管时 ,分别从根中 1/3 ,根尖 1/ 3横断 ,确定根管的类型 ,按Vertucci’s分类法对根管系统进行记录。结果 :所收集的下颌前磨牙均为单根 ,其中大多数下颌第一前磨牙的根管类型是I型 ( 1) ,93个下颌第二前磨牙的根管均为I型 ( 1) ,下颌第一前磨牙的根面沟发生率较高 ( 15 / 69) ,且此类型的下颌第一前磨牙常有双根管 ,主要是V型 ( 1-2 ) ,下颌第二前磨牙的根面沟发生率相对较低 ( 5 / 93 )。结论 :当X线片上显示下颌第一前磨牙的异常影像时 ,应进行详细的X线检查和髓腔探查 ,避免误判或治疗时遗漏根管。     

Complicated root canal morphology of mandibular first premolar in a Chinese population using the cross section method

The purpose of this study was to assess the canal anatomy and morphology of mandibular first premolars in a Chinese population. Eighty-two extracted mandibular first premolars with intact roots were collected and stored in a glutaraldehyde solution. The teeth were embedded in clear resin and the root length was measured. The roots were resected perpendicular to the long axis at 3, 6, 9, and 12 mm from the apex. The resected root surfaces were polished, rinsed, dried, and stained with methylene blue. Digital photographs of the cross-sectional root surfaces were made at 24X. The incidence of multiple canals and varied morphology was determined by two independent examiners. The results indicated that 54% of the mandibular first premolars demonstrated a single canal. Twenty-two percent contained two canals and 18% percent had C-shaped configuration. The C-shaped root canal occurred predominantly in the 3 and 6 mm sections with one or two canals coronally. A unique finding was the circumferential canal (apical delta), which was characterized by a single canal splitting into 3 or 4 canals. The incidence of circumferential canal was 6% and occurred only in the apical 3 mm cross-sections. Identification of this unique apical canal configuration and the high incidence of multiple canals in mandibular first premolars may explain endodontic treatment failure in this tooth group.     

Diagnosis and root canal treatment of a mandibular second premolar with three root canals

AIM: To present a case of a mandibular second premolar with three root canals. SUMMARY: An accurate diagnosis of the morphology of the root canal system is a prerequisite for successful root canal treatment. A review of the literature reveals a low incidence of all types of premolars with three root canals. Diagnostic means such as preoperative radiographs and examination of the pulp chamber floor aid the location of root canal orifices. The diagnostic and therapeutic problems concerning premolars with unusual anatomy are described on the basis of a clinical example. A case report describes the successful treatment of a mandibular second premolar with three root canals. KEY LEARNING POINTS: Clinicians should be aware of unusual root canal anatomy in mandibular premolars. Radiographs exposed at two different horizontal angles and their careful interpretation facilitate the search of additional root canals. The use of magnification and additional lighting are recommended for the clinical examination of the pulpal floor.     

A cone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population

Aim. The aim of this study was to evaluate the root canal number and configuration of maxillary and mandibular premolar teeth by gender, intervals for decades, tooth position and unilateral or bilateral occurrence in a Turkish population using Cone Beam Computed Tomography(CBCT) scanning. Methodology. CBCT images of 5496 maxillary and mandibular premolars from 849 patients were evaluated. The following was evaluated in all the images: numbers of roots and root canals, the morphology of the root canal configuration according to the Vertucci classification, male–female differences in the tooth position and male–female differences in unilateral or bilateral occurrence. The reliability data were analyzed with a chi-square test. Results. The most prevalent root canal frequency was the two canals (86.2%) and type IV (76.9%) configuration for maxillary first premolar, one canal (59.7%) and type I (54.5%) canal configuration for second premolar. The incidence of one canal was higher in females and the occurrence of two or three canals was more common in males. The incidence of one canal was higher on the left side of maxillary premolars and the incidence of two canals was higher on the right side. Most mandibular first (93.5%) and second (98.5%) premolars had one canal. In general, females had one root canal of the mandibular premolar, whereas males had two or three canals. The type I configuration was most common and the incidence was higher on the right side. There were some differences found in the frequency distribution of the number of root canals and configuration of maxillary and mandibular premolar teeth according to intervals for decades. Conclusion. CBCT scanning provides comprehensive information about the root canal morphology of maxillary and mandibular premolar teeth. These data may help clinicians in root canal treatment of premolar teeth.     

Radicular Grooves and Complex Root Morphologies of Mandibular Premolars Among Israeli Population

IntroductionMandibular premolars usually have one root and one root canal. Different studies found that up to 30% of mandibular premolars have more than one root canal, and up to 24% of mandibular premolars have C-shape canals. The purpose of this study was to investigate the root anatomy and the prevalence of complex root canal morphology in mandibular premolars in Israeli population.MethodsA total of 1020 Israeli patients' cone-beam computed tomography scans were screened and evaluated. A total of 1835 mandibular first premolars and 1678 mandibular second premolars were examined. Irregular root anatomy and different root canal morphologies were recorded and analyzed.ResultsThe overall prevalence of complex root morphology (types II–VIII) in mandibular first and second premolars was 21% and 2.8%, respectively. The bilateral prevalence of complex root morphology in mandibular first and second premolars was 46% and 29%, respectively. The prevalence of radicular grooves in mandibular first and second premolars with complex root morphology was 48% and 36%, respectively. No significant difference was found according to gender or the side of occurrence. However, complex root canal morphology was significantly found in mandibular premolars with radicular grooves.ConclusionsComplex root canal morphology frequently occurs in mandibular first premolars in the population of Israel. Radicular groove existence in mandibular first and second premolars is significantly related to complex root canal morphology.     

上颌前磨牙牙根及根管形态的锥形束CT研究

目的研究上颌前磨牙牙根形态、三根管的发生率和根管解剖形态,为临床诊疗提供参考。方法选取珠海市口腔医院412名患者,共779颗上颌第一前磨牙,728颗上颌第二前磨牙的锥形束CT(cone-beam computed tomography,CBCT)扫描数据,分析上颌前磨牙的牙根及根管形态,三根管的发生率、双侧对称性、根管分叉位置等。结果上颌第一前磨牙三根管发生率为1.8%,上颌第二前磨牙三根管发生率为0.3%,上颌第一前磨牙三根管发生率显著高于上颌第二前磨牙(X^2=8.304,P=0.004)。上颌第一前磨牙三根管对称率为27.3%,上颌第二前磨牙无对称三根管结构出现。上颌前磨牙解剖形态可为单根、双牙根或三牙根,其内部根管形态复杂,存在七种Vertucci根管类型,上颌第一前磨牙以VertucciⅣ型为主,上颌第二前磨牙则以VertucciⅠ型常见。三根管上颌前磨牙的根管分叉位置多见于根中或根上1/3,16颗三根管上颌前磨牙都具有三个独立的根尖孔。结论上颌前磨牙根管形态复杂多变,CBCT对发现变异和额外根管具有重要辅助作用。     

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。