青少年下颌第一恒磨牙牙根及根管的锥形束 CT 研究

目的:应用锥形束CT(CBCT)分析青少年下颌第一恒磨牙牙根及根管形态。方法:收集2012-07~12拍摄CBCT的183例12~16岁青少年患者的366颗下颌第一恒磨牙的锥形束CT影像资料,记录患者年龄、性别、观察牙位及牙根数目、根管数目及根管形态,利用SPSS 19.0软件统计分析下颌第一恒磨牙牙根及根管数目的性别差异和左右侧差异。结果:纳入研究的366颗下颌第一恒磨牙中,近中单根者365颗,远中单根者282颗(77.05%),双根者83颗(22.68%),1颗牙为C形根。近中单根双根管者356颗(97.27%),单根一根管者9颗(2.46%);远中单根一根管者229颗(62.57%),单根双根管者53颗(14.48%),双根各一根管者83颗(22.68%);C形根3根管者1颗(0.27%)。牙根及根管数目在男女之间与左右侧之间差异均无统计学意义。结论:下颌第一恒磨牙以双根居多,牙根变异主要发生在远中根,远中舌根的发生率较高;性别间与左右侧牙之间无明显差异。     

西北地区中国人下颌第一恒磨牙牙根根管数目的锥束CT研究

目的:利用锥形束CT(CBCT)观察分析西北地区中国人下颌第一恒磨牙牙根和根管数目及其变异情况,以期为临床治疗提供参考。方法:随机调取来我院放射科行CBCT检查的病人图像资料,统计分析下颌第一恒磨牙牙根和根管数目及其分布情况。结果:共获取800例病人1 600个下颌第一恒磨牙CBCT图像数据。下颌第一恒磨牙2个牙根的发生率为72.69%(1163/1600),其中2根2管的发生率3.27%,2根3管的发生率73.00%,2根4管的发生率23.73%;3个牙根的发生率为27.31%(437/1 600),其中3根3管的发生率4.12%,3根4管的发生率95.88%。下颌第一恒磨牙远中舌根的个体发生率为33.75%(270/800)。男女性别间发生率无统计学差异(P>0.05)。下颌第一恒磨牙远舌根双侧对称性的发生率61.85%(167/270),且右侧高于左侧,差异有统计学意义(P<0.05)。结论:下颌第一恒磨牙牙根和根管数目以及解剖形态存在多样性,CBCT影像可为临床根管治疗术提供可靠的依据。     

下颌第一恒磨牙远舌根的临床分析

目的调查下颌第一恒磨牙远舌根的发生率及根管治疗情况。方法临床收集378颗下颌第一恒磨牙根管治疗的完整病例,包括病历记录和术前、术中、术后X线片,记录下颌第一恒磨牙的牙根数目、根管数目及根管治疗情况。结果在378颗下颌第一恒磨牙中,远舌根的发生率为26.98％（102/378）,男、女患者和左、右侧远舌根的发生率均无统计学差异（P>0.05）。在根管治疗中,远舌根根管器械分离、侧穿和欠填的发生率高于其他根管（P<0.05）。结论远舌根在下颌第一恒磨牙中的发生率较高,发生器械分离、根管侧穿以及欠填的比例也高于其他根管。     

锥束CT对下颌第一磨牙远舌根发生率的研究

目的：利用锥束CT三维影像调查分析下颌第一磨牙远舌根的形态及发生率,以提高根管治疗质量。方法：至少具有一侧下颌第一磨牙的469例患者927颗下颌第一磨牙被纳入研究,采用锥束CT扫描获得患者的影像资料,利用NNT version 3．0软件三维影像重建,分析下颌第一磨牙远舌根的牙根形态及发生率。结果：119例共206颗下颌第一磨牙具有远舌根,远舌根在人群中的发生率为25．4％（男性65例,占27．2％;女性54例,占23．5％）,远舌根在所有牙齿中的发生率为22．2％（206颗／927颗）。绝大多数病例双侧同时具有远舌根（87例,占18．6％）,远舌根单侧出现32例（右侧27例,占5．8％;左侧5例,占1.1％）,远舌根在不同性别（P=0．678）,左右侧（P=0．870）之间的发生率没有显著性差异。结论：中国人下颌第一磨牙远舌根的发生率比较高,其形态复杂,在临床治疗中应仔细探查远舌根管是否存在,从而提高根管治疗的成功率。     

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。     

牙科数字成像系统、锥形束CT及透明牙对离体第一恒磨牙根管系统诊断价值的对比性研究

目的 对比分析牙科数字成像系统（RVG）、锥形束CT（CBCT)及透明牙3种检查方法在诊断离体第一磨牙根管系统的价值,分析第一磨牙根管影像解剖学与根管解剖学的对应关系,为第一磨牙根管治疗提供影像解剖依据。方法 拍摄269颗离体第一磨牙颊舌向、近远中向RVG和CBCT后,再制作根管染色透明牙,应用RVG、CBCT和透明牙对各牙根中上2/3、根尖1/3区根管系统和管间交通支进行分类统计,以评估CBCT在根管诊断中的应用价值。结果 CBCT对第一磨牙主根管中上2/3区的显示率达96.55%;CBCT、透明牙对第一磨牙根尖1/3区根管系统的显示差异有统计学意义（P<0.05）。上、下颌第一磨牙近中根变异较大,双或多根管与管间交通支发生率均较高。结论CBCT与透明牙在显示第一磨牙主根管系统（牙根中上2/3区）方面基本等效;在根尖1/3区透明牙对细小分歧根管的显示明显优于CBCT;RVG对多根管牙根、根尖细小分歧根管的显示明显受限;上、下颌第一磨牙近中根双或多根管与管间交通支发生率均较高。CBCT对牙根、根管的显示具有清晰直观、准确快捷的优点,是目前无创诊断根管疾病最可靠方法。     

成都地区378颗中国人下颌第一恒磨牙远舌根的临床研究

目的:调查下颌第一恒磨牙远舌根的发现率及根管治疗情况。方法:收集下颌第一恒磨牙根管治疗的完整病例,包括病历记录和术前、术中、术后X线片,记录下颌第一磨牙远舌根发生的牙位、患者性别,统计下颌第一恒磨牙远舌根的发生率和治疗情况。结果:在378颗中国人下颌第一恒磨牙根管治疗病例中,下颌第一恒磨牙远舌根的发现率为26.98%(102/378),不同牙位和性别远舌根的发现率无统计学差异(P0.05)。在男性患者中,右侧远舌根发现率高于左侧(P0.05)。在下颌第一恒磨牙根管预备过程中,器械分离和根管侧穿发生率高于其它根管;在根管充填时,欠填率高于其它根管(P0.05)。结论:远舌根在下颌第一恒磨牙中有较高发现率,发生器械分离和根管侧穿以及欠填的比例高于其它根管。     

上颌第一、第二恒磨牙牙根和根管系统的锥形束CT研究

目的：运用锥形束CT（CBCT）观察中国人群双侧上颌第一、第二磨牙的牙根和根管系统的解剖形态,为临床根管治疗提供依据。方法：选择200名患者的双侧上颌第一、第二恒磨牙（上颌第一恒磨牙354颗、上颌第二恒磨牙360颗）的CBCT扫描数据,使用NNT软件分析上颌第一、第二恒磨牙的牙根数、根管数、根管分型以及双侧对称情况。结果：上颌第一、第二磨牙主要为三根（99.44%和84.44%）。上颌第二磨牙的单根和双根较多见（15.28%）,其根管系统形态复杂,在根尖区有融合趋势。上颌第一磨牙的根管系统主要为3根四根管（78.97%）。上颌第二磨牙的三根管和四根管发现率接近（分别为47.37%和51.64%）。上颌第一磨牙的近颊根管系统主要根管分型为：Ⅳ型（57.79%）、Ⅱ型（19.83%）和Ⅰ型（15.58%）。上颌第二磨牙的近颊根管系统主要根管分型为：Ⅰ型（48.14%）、Ⅳ型（30.43%）和Ⅱ型（17.39%）。上颌第一、第二磨牙的远颊根和腭根主要为单根单根管,存在少量和罕见的变异。上颌第一、第二磨牙近颊根的根管数目和根管分型左右对称。结论：上颌第一磨牙近颊根管系统变异普遍存在,MB2根管为其主要的变异形式。上颌第二磨牙牙根数目和根管形态变异类型多,单根牙和双根牙的根管走向复杂多变。CBCT可以为识别根管形态提供准确依据。     

三根型下颌第一恒磨牙远舌根的锥形束CT研究

目的 利用锥形束CT（CBCT）观察测量三根型下颌第一恒磨牙独立远中根的解剖特点。 方法 收集三根型下颌第一恒磨牙锥形束CT影像资料共100例（男、女各50例）,测量远舌根根管口的解剖位置,及远舌根根管进入方向。 结果 远舌根根管口与远颊根根管口、近舌根根管口、近颊根根管口平均距离分别为3.11、2.90、4.13 mm;远舌根与远颊根根管上段在颊舌平面上相交角度是43.29°、近远中向角度是3.26°,性别之间无统计学差异;远舌根根管口与远颊根、近舌根根管口连线角度为女性75.10°、男性77.07°,性别之间有统计学差异。 结论 锥形束CT测量能为临床定位探查下颌第一恒磨牙远舌根管提供重要的参考依据。     

Clinical evaluation of different angulation radiograph in diagnosing distolingual root of the mandibular first molar

目的 评价不同投照角度X线根尖片诊断下颌第一磨牙远中舌根的作用.方法 选择需行根管治疗的205颗下颌第一磨牙为研究对象.术前拍X线正位根尖片及近中20°～30°偏位根尖片,对比分析是否存在远中舌根.术中根据根管的弯曲情况把远中舌根分为3类.记录下颌第一磨牙牙根和根管的数量.结果 术前X线正位、近中偏位根尖片判断48颗(48/205)下颌第一磨牙存在远中舌根,临床治疗中均确定有远中舌根,其余157颗下颌第一磨牙术中均未见远中舌根.远中舌根发生率为23.41%.48颗下颌第一磨牙远中舌根中,Ⅰ类根管22颗(45.83%);Ⅱ类根管17颗(35.41%);Ⅲ类根管9颗(18.75%).205颗下颌第一磨牙106颗(51.70%)为3根管;98颗(47.80%)为4根管;1颗(0.48%)为5根管.结论 术前多角度根尖片能准确诊断下颌第一磨牙远中舌根.     

辽宁地区汉族人下颌第二恒磨牙牙根和根管数目的锥形束CT研究

目的：利用锥形束CT（CBCT）扫描评估辽宁地区汉族人下颌第二恒磨牙牙根和根管数目的情况。方法：调取于我院口腔科行CBCT扫描患者的图像资料,统计分析下颌第二恒磨牙牙根和根管数目的情况。结果：在900例下颌第二恒磨牙中,双根的发生率为51．22％,其中82％的近中根内为双根管,100％的远中根内为单根管;三根的发生率为2．18％;融合根的发生率为46．6％,其中完全融合的锥形根占5．71％,不完全融合的C形根（C型根管）占40．89％,C型根管发生率在男女性别间差异无统计学意义（p〉0．05）,以双侧对称性分布较多,单侧发生率以右侧为多。结论：在辽宁地区汉族人中,下颌第二恒磨牙以双根或融合根居多,c形根（C型根管）的发生率较高。     

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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。     

上颌第一磨牙根管系统的研究

目的 观察上颌第一磨牙的根管系统。方法 制备50个上颌第一磨牙透明牙标本,显露根管系统的空间构型,在体视显微镜下观察并记录根管系统的形态,结合应用加以统计。结果 ①上颌第一磨牙近中颊根单根管率为66%,其中Ⅰ型占38%,双根管率为34%,远中颊根Ⅰ型占74%,腭根Ⅰ型占94%。②根管侧支、根尖分歧、根尖分叉多见于近颊根,在近颊根的发生率为40%, 远颊根的发生率为24%,腭根的发生率为6%,发生部位多见于根尖1/3。结论 上颌第一磨牙近颊根的根管系统最为复杂,根管变异较远颊根多,腭根变异最少。     

Investigation of the root canal configuration of mandibular first molars in a Taiwan Chinese population

Aim  To investigate the root form and canal morphology of mandibular first molar teeth in a Taiwan Chinese population.
Methodology  A total of 183 mandibular first molars were collected and examined visually through a dissecting microscope after rendering the teeth transparent. The number of roots, number of canals and canal configuration were recorded. The root canal morphology was categorized and compared according to Vertucci (1984).
Results  Overall 46% of the mandibular first molars had four canals and 20% had extra-distal roots (distolingual root). In addition, 97% of the specimens had two mesial canals and 46% had two distal canals. In total, 68% of teeth with two mesial canals had two separated apical foramina, and 33% of teeth with two distal canals had two apical foramina. The most common canal configurations (Vertucci, 1984) of mesial roots were type 4 (46%) and type 2 (23%). Type 1 was encountered in 54% of the distal roots.
Conclusions  The frequency of the extra-distal root on the mandibular first molar was 20%, and the incidence of three canals (Vertucci's type 8 classification) with separate apical foramina at the apex of the mesial root was 6%. The three-rooted variation of the mandibular first molar appears to be a genetic characteristic of an Asiatic racial background.     

Root and canal morphology of mandibular first and second molar teeth in a Jordanian population

Aim  To examine the root and canal morphology of mandibular permanent first and second molar teeth in a Jordanian population.
Methodology  A total of 685 extracted mandibular first and second permanent molar teeth were collected from dental clinics within north Jordan. The teeth were examined visually and the root number and morphology were recorded. After that, access cavities were prepared, pulp tissue dissolved by sodium hypochlorite and the root canals injected with Indian ink. Stained teeth were decalcified with 10% nitric acid, dehydrated with ascending concentrations of alcohol and rendered clear by immersion in methyl salicylate. The following observations were evaluated: (i) number of canals per root; (ii) number of root canals per tooth; (iii) canal configuration in each root; (iv) number and location of lateral canals and (v) presence of intercanal communications.
Results  Of 330 mandibular first molars, the majority had three (48%) or four (46%) canals, whilst 4% had a third disto-lingual root. Of 355 mandibular second molars, 58% had three canals, 19% two and 17% had four canals, whilst 10% had C-shaped roots. The most prevalent canal configuration in the mesial root of both first (53%) and second (40%) molars was type IV, and in distal roots was type I (54% in first and 79% in second molars).
Conclusions  Jordanian mandibular first and second molar teeth exhibit features close to the average Caucasian root and canal morphology.     

Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals

Objective: The aim of this study was to investigate the root and canal morphology of mandibular first and second molars in a Turkish population by using cone beam computed tomography (CBCT). Study design: CBCT images of mandibular first (n = 823) and second molar (n = 925) teeth from 605 Turkish patients were analyzed. The root canal configurations were classified according to the method of Vertucci. Results: The majority of mandibular molars (95.8% of first molars, 85.4% of second molars) had two separate roots; however, three roots were identified in 2.06% of first molars and 3.45% of second molars. C-shaped canals occurred 0.85% of first molars and 4.1% of second molars. Three canals were found in 79.9% of first molars and 72.8% of second molars. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal. The most common root morphology of first and second molars is the two rooted morphology with three canals. Both the mesial and distal roots showed wide variations in canal anatomy with type IV and type I canal configuration predominating in the mesial and distal roots, respectively. Conclusion: Vertucci type I and IV canal configurations were the most prevalent in the distal and mesial roots, respectively, of both the mandibular first and second permanent molar teeth. Key words:Cone-beam CT, Turkish, mandibular molars, root and canal morphology.     

Root and canal morphology of Burmese mandibular molars

AIM: To study the root canal morphology of Burmese mandibular molars using a canal staining and tooth clearing technique. METHODOLOGY: Mandibular molars (331) were collected from indigenous Burmese patients and designated; first (139), second (134), third (58) molars. Following pulp tissue removal and staining of the canal systems with Indian ink, the teeth were decalcified and rendered clear with methyl salicylate. Under magnification (x3), the following features were evaluated: (i) root number and morphology, (ii) number of canals per root, (iii) root canal configuration (Vertucci's classification), (iv) number of apical foramina per root, (v) number and location of lateral canals and (vi) the presence of intercanal communications. RESULTS: Most of the mandibular molars had two separate roots (90% in first molars, 58% in second molars, 53% in third molars) and three-rooted teeth were (10%) confined to first molars. C-shaped roots occurred in 22.4% of mandibular second molars and a further 14.9% had two fused roots. The majority (81-100%) of conical distal roots possessed a simple type I (single canal) configuration. Whilst the canal system of mesial roots was more complex: 52-85% contained two canals, of which type II (two orifices, one foramen) and type IV (two separate canals) were the most prevalent. A broad range of 6.5-70% had intercanal communications. Fused/single-rooted molars had a wide variety of canal system types but intercanal communications were rare except in C-shaped roots (33%) of second molars. The majority of roots of all molars contained one or two apical foramina (91-96%) and the apical third had the highest prevalence of lateral canals. CONCLUSIONS: There was a high prevalence of three-rooted mandibular first molars and C-shaped roots/canals in mandibular second molars from a Burmese population. Conical roots tend to have simple canal systems, whilst flatter/broader roots have more complex canal systems.     

运用锥束CT对恒前牙根管变异的分析

目的采用锥束CT扫描所得图像数据,统计和分析前牙根管的变异。方法收集600例患者7200颗前牙图像数据,运用NNT软件,在冠状面、矢状面和横断面进行观察,统计和分析根管的数目、形态变异,根管类型,牙根数及两侧根管变异的对称性。结果 1根管数目：上颌前牙均为单根管,未见到根管变异;下颌前牙中330颗牙出现变异根管,为9.16%;2根管类型：上颌前牙均为Ⅰ型,下颌前牙Ⅰ型90.84%,Ⅱ型0.83%,Ⅲ型6.67%,Ⅳ型1.33%,Ⅴ型0.33%;3根管变异的对称性：上颌前牙不存在变异根管对称;下颌前牙两侧变异根管对称率：中切牙69.2%;侧切牙86.1%;尖牙66.7%;4牙根数：前牙除2例下颌尖牙为双根外,余均为单根。结论上颌前牙未见根管和牙根的变异;下颌前牙根管形态较复杂,根管变异率为9.16%,CBCT可准确发现根管变异。     

Root and canal morphology of Thai mandibular molars

AIM: To investigate the root and canal morphology of 351 mandibular permanent molars collected from an indigenous Thai population. METHODOLOGY: The cleaned teeth were accessed, the pulp dissolved by sodium hypochlorite under ultrasonication and the pulp system injected with Indian ink. The teeth were rendered clear by demineralization and immersion in methyl salicylate. The following observations were made: (i) number of roots and their morphology; (ii) number of root canals per tooth; (iii) number of root canals per root; (iv) root canal configuration in each root using Vertucci's classification, with additional modifications; and (v) presence and location of lateral canals and intercanal communications. RESULTS: Of 118 mandibular first molars, 13% had a third disto-lingual root. In three-rooted teeth, 80% of the main distal roots and 100% of the disto-lingual roots had type 1 canal systems. Of 60 mandibular second molars, 10% had C-shaped roots, the majority of which had type 1 (33%) or type IV (33%) canal systems. Of 173 third molars, 68% had two separate roots, 20% had fused roots and 11% had a single C-shaped root; the majority had two canals (61%). CONCLUSIONS: This study suggests that Thai molars exhibit features of both Caucasian and Chinese teeth.