Root and Canal Morphology of Maxillary First Premolar Teeth in a Ugandan Population

Aim : To determine the variations in the root and canal morphology of the maxillary first premolar teeth in a Ugandan population. Methodology : Extracted maxillary first premolar teeth (n = 202) were evaluated in this study. The specimens had their pulp chambers de-roofed. They were decalcified in nitric acid and made transparent with methyl salicylate. Indian ink was injected into the root canals to display their configuration. Results : One hundred and forty eight (73.3%) of the specimens had two roots, of which 16.9% (n = 25) had fused roots. About 26.7% (n = 54) of the specimens were single rooted. Eleven (20.4%) of the single rooted specimens had one canal of either Vertucci type I, III, V or VII configuration while 79.6% (n = 43) of the specimens had two canals of either Vertucci type II, IV or VI configuration. The two-rooted specimens exhibited Vertucci type IV and VIII canal configuration: 96.6% and 3.4%, respectively. The single rooted teeth had a higher prevalence of lateral canals, canal intercommunications and multiple apical foramina as compared to the two-rooted specimens. Conclusion : The maxillary first premolar teeth in this Ugandan population showed a higher prevalence of two-root morphology with majority of the roots having Vertucci type IV canal configuration. There was no three-root anomaly recorded in the present material.

Root canal morphology and configuration of 123 maxillary second molars by means of micro-CT

The aim of this study was to investigate the root canal configuration, accessory canals and number of main foramina of 123 maxillary second molars by means of micro-computed tomography. The teeth were scanned and reproduced with 3D software imaging. The root canal configuration and number of main foramina were evaluated by means of a four-digit system. The morphological complexity of human maxillary second molars is depicted by the number of accessory and connecting canals. The most frequently observed root canal configurations in the mesiobuccal root were 2-2-2/2 （19.5%）, 2-2-1/1 （14.6%） and 2-1-1/1 （13.0%）. A 1-1-1/1 configuration was observed in 93.5% and in 96.7% in the distobuccal and palatal roots, respectively. The MB1 mot canal had one accessory canal （18.7%）, and 8.9% of the MB2 root canal had one or two accessory canals. The distobuccal （11.3%） and palatal （14.6%） root canals had at least one accessory canal, and connecting canals were observed in 16.3% of mesiobuccal roots. The MB1, MB2, distobuccal and palatal root canals had one main foramen in 99.2%, 43.1%, 98.4% and 99.2% of samples, respectively. In the mesiobuccal root, one accessory foramen was detected in 14.6%, two were detected in 7.3%, and three were detected in 5.7%. The distobuccal root showed one or two accessory foramina in 9.1% of samples. The root canal configuration of maxillary second molars is quite heterogeneous; the mesiobuccal root has predominantly two root canal entrances （58.4%, 1 in 41.1%） with one main foramen （54.4%）. Two main foramina were observed in 43.0%. Morphological variations, connecting and accessory canals were observed in all apical thirds.

Endodontic management of the maxillary first molar with special root canals:A case report and review of the literature

BACKGROUND As the complex anatomy of maxillary first molars is one of the major challenges in endodontic therapy,knowledge of the complicated root canal anatomy and configuration is crucial to ensure the success of endodontic treatment and prognosis.This article presents an endodontically managed left maxillary first molar with an unusual palatal root morphology.The available literature on the anatomic variation of maxillary first molars is also reviewed.CASE SUMMARY A 36-year-old man with no medical history presented to the Stomatology Department of Peking University Third Hospital complaining of a toothache during mastication in the maxillary left posterior region for approximately 3 mo.He had a spontaneous and intermittent toothache that had worsened,particularly at night.The diagnosis based on clinical examination,X-ray imaging,and cone beam computed tomography(CBCT)was symptomatic irreversible pulpitis.Nonsurgical endodontic therapy was performed for the left maxillary first molar.Five root canals revealed by CBCT included a special palatal root canal(1-2-1-shaped),two mesiobuccal root canals,and one distobuccal root canal.Evaluation of the CBCT images confirmed the root canal morphology and the clinician performed more effective cleaning,obturation,and therapy.Finally,the tooth was restored using composite resin,and the patient was satisfied with the result.CONCLUSION CBCT and a complete review of the literature may be beneficial for investigating the root canal system to achieve a biological and functional therapeutic effect.

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.

Maxillary Second Molar with Single Root and Single Canal—Case Report

The maxillary second molar contains three roots and three canals. Variations of the maxillary second molar are reported in numerous studies in vitro and in vivo. Dentists are required to have adequate knowledge related to root canal morphology and their possible variations. The aim of this study was to present a case report about a diagnosis and treatment in maxillary second molar with single root and single canal. It is concluded that the diagnosing of these unusual cases is of high importance for successful endodontic treatment of these teeth.

Root Canal Morphology of Maxillary Premolars among the Elderly

Reportedly,maxillary premolars are the most complex teeth for performing endodontic treatment,[1] with root canals varying based on race,genetic predisposition,diet,region,gender,[2] and perhaps age.To date,few detailed studies have been conducted to assess number of roots and root canal morphology of maxillary premolars in the elderly.The present study analyzed root canal morphology of maxillary premolars in elderly individuals using cone-beam computed tomography （CBCT）,which has substantial clinical value in guiding endodontic treatment.[3]

CBCT测量不同年龄人群上颌前磨牙根管形态及增龄性改变的研究

目的:本研究利用锥形束计算机断层扫描(CBCT)来评估上颌第一和第二前磨牙根管系统的形态和增龄性变化。方法:我们收集了724位患者的上颌第一、第二前恒磨牙的CBCT资料。将这些患者分为六个年龄段:15~24岁年龄组、25~34岁年龄组、35~44岁年龄组、45~54岁年龄组、55~64岁年龄组和≥65岁年龄组。我们根据Vertucci分类法对上颌第一和第二前磨牙的根管形态进行统计分析,并分别测量了颊侧髓角高度,舌侧髓角高度,髓室顶-釉牙骨质界,颊舌髓角间距,髓室底-釉牙骨质界,颊侧牙本质厚度,颊舌向根管径,舌侧牙本质厚度,根管口间隔距离,近中牙本质厚度,近远中髓腔径,远中牙本质厚度。结果:在第一和第二前磨牙根管形态与性别的关系分析没有显示出男性和女性之间牙根数量的统计学显著差异。另外,随着年龄的增长,所有年龄段的上颌第一、第二磨牙中,颊侧髓角高度、舌侧髓角高度、髓室顶-釉牙骨质界、颊舌髓角间距离、颊舌向根管径和近远中髓腔径度都会减小。在这些指标中,颊侧髓角高度、舌侧髓角高度、颊舌髓角间距离和近远中髓腔径度的变化是一致的(P<0.01),并且在统计学上有显著差异。上颌第一前磨牙的颊侧牙本质厚度和舌侧牙本质厚度,以及上颌第二前磨牙的近中牙本质厚度和远中牙本质厚度都会随着年龄的增长而增厚,其中近中牙本质厚度的变化是显著的(P<0.01),具有显著的统计学意义。结论:第一和第二前磨牙根管形态与性别的关系分析与性别无关;其根管系统的增龄性变化可以归因于牙本质沉积和继发性牙本质形成等因素,这些因素可能会随着时间的推移改变根管系统的形状和增加其复杂性。

上颌第一磨牙解剖结构的锥形束CT研究

目的应用锥形束计算机断层扫描法(CBCT)研究上颌第一磨牙的牙体及根管解剖结构,为上颌第一磨牙的临床诊疗提供数据支持。方法根据纳入及排除标准,选择上颌第一磨牙完整的18~25岁健康人群共计401(男196,女205)例为研究对象,拍摄CBCT影像,使用SmartVPro软件测量分析牙体形态、根管形态,采用SPSS 26.0软件对数据进行统计学处理。结果右侧上颌第一磨牙平均全长为(20.22±1.72)mm,左侧上颌第一磨牙平均全长为(20.24±1.74)mm;全长、冠宽、颈宽在左右侧上颌第一磨牙间无明显差异(P>0.05),左侧上颌第一磨牙冠长、根长、冠厚、颈厚显著大于右侧上颌第一磨牙(P<0.05);男性全长、根长、冠厚、颈厚、冠宽、颈宽等显著大于女性(P<0.05)。左右侧上颌第一磨牙根管形态对称,三根型牙根最常见,发生率为98.75%,双根型牙根的发生率为1.25%;根管数目最常见为四根管,发生率为63.47%,其次为三根管,发生率为35.78%;近颊第二根管发生率为63.84%。近颊根管分型以VertucciⅣ型根管为主,在左右侧上颌第一磨牙中分别占比为62.59%、64.59%,远颊根及腭根则以VertucciⅠ型根管为主,远颊根VertucciⅠ型根管占比为97.00%,左右侧上颌第一磨牙腭根VertucciⅠ型根管占比则分别为98.75%、98.50%。结论上颌第一磨牙牙体形态在性别间存在显著差异,且根管系统复杂多变,相关数据有望为上颌第一磨牙牙体牙髓病的防治提供指导。

上颌第一前磨牙牙根数目和根管形态的研究

目的:研究上颌第一前磨牙的牙根数目和根管形态。方法:制备上颌第一前磨牙的透明牙标本,记录牙根数目,并在牙科手术显微镜下观察其根管形态。结果:共获得268个透明牙标本,其中单根牙201个(75.00%)、双根牙62个(23.13%)、三根牙5个(1.87%)。单根管、双根管和三根管的发生率分别为3.06%、83.58%和1.87%,其他类型根管发生率为1.49%。侧支根管发生率为25.00%,根尖孔大多位于牙根的侧方。结论:上颌第一前磨牙的形态从多到少依次是单根双根管、双根双根管、单根单根管和其他。

广东珠江三角洲地区人下颌第一前磨牙根管解剖形态的研究

目的通过普通X线片法、牙科手术显微镜下探查结合插诊断丝拍片法以及透明标本法,了解广东珠江三角洲地区人下颌第一前磨牙根管系统解剖特征。方法筛选出广东珠江三角洲地区人离体下颌第一前磨牙363颗为研究对象。将离体牙拍摄颊舌向、近远中向数字化X线片,初步判断根管数目。将离体牙开髓,采用牙科手术显微镜下观察法和离体牙透明标本法,观察并记录各牙齿的根管数目、类型。结果不同研究方法所得结果不同。普通X线片法多根管发现率为7.71%;牙科手术显微镜下探查结合插诊断丝拍片法多根管发现率为33.33%;透明标本法显示多根管发生率为34.44%,其中双根管27.82%,三根管5.79%,四根管0.83%。根管类型多样化,出现Vertuc-ci分类Ⅱ、Ⅲ、Ⅳ、Ⅴ及附加型(3-1)等。双根管的下颌第一前磨牙的髓底图特征为颊舌向直线,三、四根管下颌第一前磨牙的髓底图呈平台状。结论广东珠江三角洲地区人下颌第一前磨牙多根管出现率高,根管类型多样。牙科手术显微镜下探查法和插诊断丝拍片法结合,能够较为准确地判断下颌第一前磨牙的根管数目和类型。

1684个上颌第二磨牙根管构型的CBCT研究

目的:用CBCT研究荆州地区汉族人群上颌第二磨牙牙根和根管解剖形态。方法:收集CBCT检查的影像资料进行回顾性分析,从中筛选出842名患者共1 684个上颌第二磨牙,记录患者的性别、年龄、牙位、牙根和根管数目,并采用Vertucci分类法对根管构型进行分类描述。结果:(1)上颌第二磨牙中,3根的发生率最高(77.4%),其次为单根(11.2%);双根和4根的发生率分别为9.7%、1.7%;(2)1 304个3根上颌第二磨牙中,65.6%的近中颊根根管为1-1型,34.4%的近中颊根存在第二根管;(3)上颌第二磨牙中,Ⅱ类牙根的检出率男性和女性分别为26.8%和16.6%(P<0.05),V类牙根的检出率男性和女性分别为8.3%和13.9%(P<0.05)。结论:上颌第二磨牙牙根和根管变异较大,存在一定的性别差异。

中国人下颌第一前磨牙牙根及根管形态的研究

目的对中国人下颌第一前磨牙牙根及根管形态的研究作一系统性的回顾分析。方法通过国内外数据库检索所有与中国人下颌第一前磨牙牙根及根管形态相关的文献以及病例报道,记录下颌第一前磨牙牙根数目、根管数目、根管分型、根尖孔数目和根尖孔位置。结果 1 324颗研究牙根数目的下颌第一前磨牙中,单个牙根发生率占93.1%,2个牙根占6.6%,3个牙根占0.3%,其中未发现4个牙根的存在;5 745颗研究根管数目的下颌第一前磨牙中,单根管发生率占75.2%,多根管占24.8%;4 650颗研究根管分型的下颌第一前磨牙中,Ⅰ型根管发生率占75.1%,Ⅱ型占2.0%,Ⅲ型占1.7%,Ⅳ型占5.5%,Ⅴ型占12.5%,Ⅵ型占0.1%,Ⅶ型<0.1%,Ⅷ型占0.5%,其他根管类型占2.6%;478颗研究根尖孔数目的下颌第一前磨牙中,只有1个根尖孔的占63.2%,有2个根尖孔的占25.7%,有3个根尖孔的占9.0%,有4个根尖孔的占2.1%;771颗研究根尖孔开口位置的下颌第一前磨牙中,包含946个根尖孔,其中根尖孔位于根尖顶端的占56.6%,位于根尖侧方的占43.4%。结论中国人下颌第一前磨牙以单牙根单根管为主,两牙根两根管常见,两根管中主要以Ⅳ型和Ⅴ型根管为主,其他根管分型发生率较低,但包含根管类型较多。此外,下颌第一前磨牙根尖孔数目变化大,约占一半的根尖孔位于根尖侧方。

成都地区成人上颌第一前磨牙的离体解剖形态观察

目的探讨成都地区成人上颌第一前磨牙的解剖外形及其根管的形态特点,为牙体牙髓病的临床治疗提供理论依据。方法游标卡尺测量105颗上颌第一前磨牙的牙体各项长度指标;肉眼观察牙根形态;拍摄X线片,观察根管形态及类型。结果牙体各项指标测量值均呈正态分布,根长和牙长差异较大。冠长-牙长及根长-牙长间存在相关性及直线回归关系,其他指标间也广泛存在。上颌第一前磨牙单根或融合根居多,占74.3%。根管数目1～3,以两根管(68.5%)居多,主要有Ⅰ型、Ⅱ型、Ⅳ型和Ⅴ型。结论本实验结果可为成都地区成人上颌第一前磨牙的临床治疗提供理论参考。上颌第一前磨牙多根管率较高(71.4%),应该引起临床医生的高度重视。

下颌切牙及下颌第一前磨牙根管形态的体外研究

目的:采用透明标本法观察下颌切牙、下颌第一前磨牙根管系统的类型和特点。方法: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切牙120个、下颌第一前磨牙156个,开髓、去髓,注入墨水,制成透明标本。观察根管数目,按Vertucci分类法对根管系统进行分类,测量多根管牙根管分叉处至釉牙骨质界的距离。结果:下颌切牙、下颌第一前磨牙多根管的发生率分别为28.2%、30.9%,多根管以1-2型为主,多数在根管中段出现分叉。结论:下颌切牙、下颌第一前磨牙根管系统复杂,了解其形态特征有利于避免遗漏根管。

离体上颌前磨牙根管治疗两个阶段抗折力及折裂模式的比较

目的:对根管治疗术中根管预备结束和充填完成两个阶段牙齿的抗折力进行定量比较,并对折裂模式进行观察。方法:以上颌离体前磨牙30个为研究对象,先根据形态分成区组,每区组各3个牙。再用抽签法将其随机分入处理组,每组10个。对照组:不作任何处理;预备组:模拟开髓和根管预备;完成组:与预备组相同的处理后,进行根管充填和复合树脂修复。用万能测试仪测试牙齿的抗折力;将折裂模式分为"轻度"和"重度"两级,由2名专家独立盲法评价。结果:各组的抗折力分别为:(1171.2±140.10)N,(514.8±219.23)N和(911.0±86.77)N。对照组最高,预备组最低。方差分析显示组间差别显著(F=26.50,P=0.0003)。各组折裂牙属于"重度"者分别有2、6、4个,对照组最少,预备组最多。结论:根管治疗术会削弱牙齿的抗折力,尤其在根管预备结束阶段。

离体上颌第一前磨牙根管颊舌向弯曲的研究

目的 确定人上颌第一前磨牙的颊舌向根管弯曲程度和情况。方法 收集115颗离体的上颌第一 前磨牙,拍近远中向的X线片,用Photoshop5.0软件分析根管,用Weine氏法测量根管的弯曲度,测量的角度大于 18°时,则认为根管存在明显的弯曲,根管的构型采用Vertucci分类法。结果 20%的上颌第一前磨牙在颊舌向存 在明显的根管弯曲,单根管的牙齿无明显的颊舌向根管弯曲,大多数的颊舌向根管弯曲发生于双根双管的牙齿, 37%的双根牙齿有根管弯曲,根管弯曲的发生部位多为牙根的偏根尖部分。结论 上颌第一前磨牙的颊舌向根管 弯曲发生率为20%,多在根尖1/3出现1个弯曲。

乳牙根管系统的形态研究

目的探讨乳牙根管形态的规律。方法将一组完整的离体乳牙行透明标本制作后,再应用体视显微镜观察并记录其根管形态及其分类。结果乳前牙除1颗为单双混合根管外,92%的牙体为单根单管型;上颌乳磨牙的根管形态均为三根管型,下颌乳磨牙的根管形态均为四根管型,并且根管侧枝和管间吻合常见。结论乳前牙根管形态相对简单,而乳磨牙的根管系统比较复杂。

下颌前磨牙根管形态的锥形束CT研究

目的:利用CBCT评估下颌前磨牙根管解剖形态。方法:收集CBCT检查下颌前磨牙的患者资料560例,记录患者的姓名、性别、年龄、牙位、牙根和根管数目,并采用Vertucci分类法对根管构型进行分类描述。结果:1下颌第一前磨牙中,单根的发生率最高(84.2%),双根为3.8%;其中85.2%的牙根表现为单根管,双根管检出率为12.7%;根管构型中,Ⅰ型根管最为常见(85.2%),其次是V型根管(9.7%);Ⅰ型根管的检出率女性高于男性(P<0.05),男性出现变异根管(V型和C型)的可能性高于女性(P<0.05);2下颌第二前磨牙中,99.8%的牙表现为单根;其根管构型中,Ⅰ型根管占99.5%,双根管和C形根管分别为0.4%和0.1%。结论:下颌第一前磨牙变异根管出现率较高,下颌第二前磨牙单根单管常见。

基于锥形束CT对重庆地区人下颌第一前磨牙根管形态及牙根数目的研究

目的通过锥形束CT数字影像研究重庆地区人下颌第一前磨牙的根管形态及牙根数目。方法筛选重庆地区567例患者的锥形束CT数字影像(男:293例,女:274例),共1 124颗下颌第一前磨牙,通过i-CAT软件对其轴面、矢状面、冠状面进行分析,记录其根管形态及牙根数目。结果 1 124颗下颌第一前磨牙参考Vertucci根管形态分类法进行分类,发生率分别为:Ⅰ型71.17%,多根管型28.83%[其中Ⅱ型4.45%,Ⅳ型1.16%,V型7.38%,Ⅸ型(双根双根管)13.61%,X型(其他)2.22%];左右侧下颌第一前磨牙同一根管类型发生率相比较,差异均无统计学意义(P>0.05);男性多根管发生率(32.29%)高于女性(25.18%),差异具有统计学意义(P=0.009)。结论重庆地区人下颌第一前磨牙根管系统中多根管及双牙根的发生率较高,根管类型多样,且有性别差异。通过对根管系统的了解,有助于提高根管治疗的成功率。

离体上颌第二前磨牙根管和牙根情况的研究

目的 观察上颌第二前磨牙的牙根及根管形态。方法 2 13颗离体的上颌第二前磨牙 ,对牙齿进行近远中向X线照像 ,并从根中 1/ 3横断探测确实 ,Vertucci’s分类法对根管系统进行记录。结果 185颗牙是单根(87% ) ,2 8颗牙是双根 (13% ) ,而单根牙中最多的是 1个根管 [TypeⅠ (1) ],占牙齿总数的 4 3% ,其次是单根双管TypeⅡ (2 - 1) ,即颊舌 2个根管 ,至根尖又合并成一个根尖孔 ,占牙齿总数的 35 %。 结论 上颌第二前磨牙主要是单根 ,单个根尖孔的发生率高 (78% )。