3种技术诊断离体第一第二磨牙根管系统对比研究

目的以透明牙技术为参照,探讨牙科数字成像系统（radiovisiography,RVG）和显微CT（micro-computed tomography,MCT）扫描两种检查技术在研究离体磨牙根管系统解剖结构中的作用,为磨牙根管治疗提供影像学依据。方法253颗离体磨牙分别摄颊舌向、近远中向RVG和行MCT扫描,再制作根管染色透明牙,应用RVG、MCT和透明牙对各牙根中上2/3、根尖1/3区根管系统结构和管间交通支进行分类统计,以评估RVG、MCT技术在根管结构诊断中的应用价值。结果透明牙、MCT两组显示牙根中上2/3区根管系统均显著优于RVG（P〈0.05）;MCT与透明牙对磨牙中上2/3区根管系统的显示差异无统计学意义（P〉0.05）。MCT、透明牙、RVG对磨牙根尖1/3区根管系统的显示差异有统计学意义（P〈0.05）,根管显示率透明牙为100%,MCT为89.84%,RVG为77.97%。结论MCT与透明牙在显示牙根中上2/3区根管系统方面基本等效;在根尖1/3区透明牙对变异细小分歧根管的显示优于MCT及RVG技术,MCT技术在根尖1/3区细小分歧的显示明显优于RVG。     

下颌磨牙融合根的根管系统研究

目的:探索下颌磨牙融合形牙根的根管系统构筑规律。方法:100例融合根形态的下颌磨牙采用透明法显示根管系统的空间构筑,在体视显微镜下观测并记录其形态图象。结果:融合根外形与其内的主根管分型间并无规律可循,而侧副管以管间吻合常见。结论:主根管可分为"多支型"和"直通型"两类,传统的根管分型在融合根中已不适用。     

辽沈地区人群下颌第一磨牙牙根及根管解剖的CBCT观察

目的：利用锥形束CT（CBCT）观察辽沈地区人群下颌第一磨牙牙根及根管解剖形态,了解常见的变异型.方法：收集316名患者共548颗下颌第一恒磨牙CBCT影像,分别记录患者的姓名、性别、牙位、牙根数、根管数、变异型.启动Invivo Dental 5.0软件观察根管形态,分析辽沈地区人群下颌第一恒磨牙牙根及根管形态分布特点.结果：在548颗下颌第一磨牙中,2个牙根的下颌第一磨牙发生率为73.72％（404/548）;远舌根的发生率为26.28％（144/548）,男、女性别及左、右侧牙远舌根发生率比较差异无统计学意义;根管变异型以2根3根管为主,占51.64％（283/548）.结论：辽沈地区人群下颌第一磨牙远舌根的发生率较高;大部分有2个牙根;2个牙根3个根管是主要的根管分布类型;CBCT对于判断牙根和根管的解剖形态有诸多优势,可以为临床根管治疗提供参考.     

下颌第一恒磨牙的形态识别及其临床意义

下颌第一恒磨牙的解剖形态复杂多样，可能存在根管峡部、管间交通支、额外根管、危险区、弯曲根管等特殊结构，个体差异较大。文章系统阐述下颌第一恒磨牙牙根和根管的解剖形态特点，对复杂及特殊结构进行具体分析并提供相应的临床诊疗策略。     

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。     

基于锥形束CT影像的下颌第一恒磨牙根管治疗后根分叉病变的分类研究

目的 探讨基于口腔颌面锥形束CT(cone beam CT,CBCT)的下颌第一恒磨牙根管治疗后根分叉病变（furcation involvement,FI）的分类,为根分叉病变个体化治疗提供参考。方法 回顾性收集就诊于南京大学医学院附属口腔医院的163例患者的164颗下颌第一恒磨牙根管治疗后根分叉病变的CBCT影像资料。根据患牙牙周及根尖周骨吸收的形态和范围,髓室底和根管侧壁剩余牙本质的厚度,结合患者全口其他牙情况,将根分叉病变分为牙周来源、根尖周来源、穿孔性因素及混合来源;并对根尖周来源根分叉病变患牙的根管充填情况进行评估。结果 164颗下颌第一恒磨牙根管治疗后根分叉病变患牙中,根尖周来源的根分叉病变最多,占41.5%,其次是混合来源,占26.2%,穿孔性因素占18.3%,牙周来源占14.0%。68例根尖周来源的根分叉病变患牙中,CBCT图像显示48.5%的患牙根充良好,44.1%的患牙根充不全,7.4%的患牙超填。43例混合来源的根分叉病变患牙中,同时存在牙周来源和根尖周来源的患牙最多,占72.1%。结论 CBCT可对根分叉病变进行细致的评价并进行分类,对临床治疗有指导意义。     

根管峡区的定位、发生率及临床意义

根管峡区(root canal isthmus,RCI)是位于同一牙根内、根管之间含有牙髓或牙髓衍生组织,呈现为带状狭窄的连接或含有交通支及横向吻合的解剖学结构,它常存在于含有两个根管的牙根中,解剖结构复杂.不同牙位的RCI发生率不尽相同,发生率最高的部位是下颌第一磨牙近中根和上颌第一磨牙近中颊根.RCI的存在增加了根...     

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。     

温州地区人上颌第一恒磨牙牙根解剖的研究

目的:了解温州地区人上颌第一恒磨牙牙根解剖基本特点。方法:收集60个温州地区人上颌第一恒磨牙,肉眼观察牙根外形、根尖孔数目、类型;游标卡尺测量牙根长度指标、根尖孔到牙根顶点的距离;透明牙标本法观察根管系统。结果:上颌第一恒磨牙55.4%根尖孔不在根尖顶点,近中颊根双根管率为61.6%,3根管率为1.7%。结论:温州地区人上颌第一恒磨牙牙根、根管形态复杂,应给予足够的重视。     

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。     

Evaluation of root canal morphology of human primary molars by using CBCT and comprehensive review of the literature

Objective Knowledge of primary tooth morphology is essential for clinical dentistry, especially for root canal treatment and dental traumatology. However, this has not been well documented to date with a large sample. This study was carried out to investigate the variation in number and morphology of the root canals of the primary molars, to study the applicability of cone beam computerized tomography (CBCT) in assessing the same and to provide a comprehensive review of the literature. Materials and methods A total of 343 primary molars, without any root resorption, were divided into four main groups including the maxillary first molars, maxillary second molars, mandibular first molars and mandibular second molars. All of them were analysed in CBCT images in the axial, sagittal and coronal planes. Various parameters such as the number of roots, number of canals, the root canal type, diameter of root and root canal and root canal curvature were studied. Results Primary molars in all four groups showed variability in the number of roots and root canals. As far as length of the roots was concerned, the palatal root of the maxillary molar was found to be longest, while the distobuccal root was shortest. In mandibular molars, the mesial root was longer than the distal root. The length of distobuccal root canal of the maxillary molars and the distolingual canal of the mandibular molars was found to be shortest. The number of roots and root canals varied from two to four and three to four, respectively. The maxillary molars exhibited more one-canal than two-canal roots. Conclusion The present study provides comprehensive information to the existing literature concerning the variation in root canal morphology of the maxillary and mandibular primary molar teeth. These data may help clinicians in the root canal treatment of these teeth.     

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.     

A preliminary in vitro study of the incidence and position of the root canal isthmus in maxillary and mandibular first molars

AIM: To investigate in vitro the incidence and position of the root canal isthmus in extracted mesiobuccal roots of maxillary and mesial roots of mandibular first molars. METHODOLOGY: Fifty maxillary and 50 mandibular molars were included in the study. The mesiobuccal roots of maxillary molars and the mesial roots of mandibular molars were sectioned from their crowns in the furcation region and embedded in clear resin. Transverse serial 1-mm-thick sections from the apical 6 mm were prepared. The apical side of each section was stained with India ink and observed through a light microscope. The sample images were saved to disk using a digital camera and the root canals in terms of the number present and the incidence and classification of isthmuses. RESULTS: In the mesiobuccal root of the maxillary first molars, 70% had one canal, whereas 29.5% had two canals. In the mesial root of mandibular molars, 41% had one canal, whereas 59% had two canals. In some sections, more than two canals were found close to the apical foramen. The isthmus incidence was greatest 3-5 mm from the apex. In teeth having two canals, a complete or partial isthmus was frequently observed in the sections between 3 and 4 mm from the apex. Of the isthmuses present, 22% were complete and 37% partial in mandibular molars and 17.3% were complete and 11.7% partial in maxillary molars. CONCLUSIONS: The incidence of isthmus in the mesiobuccal root of the maxillary first molars and in the mesial root of the mandibular first molars was high, particularly in sections 3-5 mm from the apex. Cleaning the isthmus is a major challenge during root canal treatment.     

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.     

Analisi della morfologia radicolare e canalare di molari superiori ed inferiori in una popolazione Caucasica: studio in vivo alla CBCT

AimTo investigate the root and canal morphology of maxillary and mandibular permanent molar teeth in a Caucasian population by using Cone Beam Computed Tomography (CBCT).MethodsA total of 596 permanent molars were included. The number of roots, the number of canals per root and the root canal configurations according to the method of Vertucci were recorded.ResultsAlmost all of maxillary first molars (95.7%) had three separate roots; however, 40.3% of mesiobuccal roots had two canals (MB2). Of 157 maxillary second molars, 88.5% had three roots. Among the mesiobuccal roots, 15.1% had two canals. The majority of mandibular molars (100% of first molars, 89.4% of second molars) had two separate roots. Most distal roots had a simple type I configuration, whereas mesial roots had more complex canal systems, with more than one canal.ConclusionsCBCT is an efficient method of studying root canal systems.     

Symmetry of Root and Root Canal Morphology of Maxillary and Mandibular Molars in a White Population: A Cone-beam Computed Tomography Study In Vivo

Introduction

The aim of the present study was to use cone-beam computed tomography (CBCT) to analyze root canal anatomy and symmetry of maxillary and mandibular first and second molar teeth of a white population.

Methods

A total of 201 patients who required CBCT examinations as part of their dental diagnosis and treatment were enrolled in the present study. Overall, 596 healthy, untreated, well-developed maxillary and mandibular molar teeth (161 maxillary first molars, 157 maxillary second molars, 117 mandibular first molars, and 161 mandibular second molars) were examined by CBCT to establish the symmetry in root and canal anatomy between right and left sides in the same patient by evaluating the number of roots and root canals and the root canal configuration.

Results

Three separate roots with 3 separate canals was the normal anatomy of maxillary first and second molars. Most mandibular first and second molars had 2 separate roots, and the majority had 3 canals. In the present study, first molars, both maxillary and mandibular, exhibited greater asymmetry than the second molars. Maxillary first molars were found to be symmetrical in 71.1% of patients, whereas maxillary second molars were symmetrical in 79.6%. The remaining 28.9% and 20.4% of patients, respectively, showed asymmetry. Around 30% of the mandibular first molars and 20% of the mandibular second molars showed asymmetry.

Conclusions

The results of the present study reported a percentage of symmetry that varied from 70%–81%. These variations in symmetry should be taken in high consideration when treating 2 opposite molars in the same patient, because their anatomy may be different in up to 30% of the cases.     

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.     

Root and canal morphology of permanent mandibular molars in a Sri Lankan population

The main purpose of this study was to investigate the root and canal morphology of Sri Lankan mandibular molars and to determine the affinities of these morphological variations to those of people of European and Asian origin. Two hundred mandibular first and second molars were examined. The number of roots and the prevalence of C-shaped (gutter-shaped) roots in mandibular second molars were recorded. Root canal morphology was studied using a clearing technique. The examination of root canal systems of the teeth was based on Vertucci's classification. Among mandibular first molars, only 3% had three roots. Mesial roots of the first molar typically presented with two canals and two apical foramina with type IV, V, or VI canal configuration. Most distal roots of the first molar presented with a type I canal configuration. The remainder were distributed mainly between types III and V. Among mandibular second molars, 6% had single C-shaped roots, while C-shaped canals were found in only 2%. The majority of mesial roots of the second molar showed one or two canals, with one apical foramen with type I, II, or III canal morphology. In addition, the distal root commonly showed type I canal configuration. Intercanal communications and lateral canals were more frequently seen in the first molar than in the second. The root canal morphology in mandibular molars varies among population groups. Mandibular root and canal morphology of Sri Lankan people has closer affinities with that of people of European than of East Asian origin.     

Root canal systems of the mandibular and maxillary first permanent molar teeth of south Asian Pakistanis

AIM: The purpose of the present ex vivo study was to investigate variations in the root canal systems of mandibular and maxillary first permanent molar teeth of South Asian Pakistanis. METHODOLOGY: The root canal systems of a sample of 30 mandibular and 30 maxillary first permanent molar teeth extracted from South Asian Pakistanis were studied using a clearing technique. RESULTS: The mesial roots of the mandibular molar teeth typically presented with two canals (97%) of type II, IV or VI configuration. The distal roots of these teeth presented with a single canal (50%) of type I or V configuration or with two canals (50%) of type II, IV or VI. The prevalence of four root canals in two-rooted mandibular first permanent molar teeth was 47%. In maxillary molar teeth the mesial roots with a single canal (47%) were type I or type V; those with two canals (53%) were type II, IV or type VI. The distal and palatal roots that presented as a single canal (100%) were type I or type V configuration. The prevalence of four root canals in three-rooted maxillary first permanent molar teeth was 53%. CONCLUSION: It is concluded that four root canals in mandibular and maxillary first permanent molar teeth of South Asian Pakistanis is a common occurrence. The distribution of the different configurations of root canal systems in this population differed from that in Caucasian groups, suggesting that variations in root canal systems may be attributed to racial divergence.