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.     

����һĥ�����мո�����ϵͳ׶����CTӰ��ѧ�۲�

目的利用锥形柬计算机断层扫描（CBCT）研究上颌第一磨牙近中颊根第二根管（MB2）发生率、根管解剖形态以及根管口位置分布。方法随机选取2011-2013年航天中心医院口腔科20～30岁患者CBCT影像160张（男80张、女80张）。平行近中颊根长轴平面观察其根管形态,并按照Vertucci分类统计。水平面观察根管口的位置,记录MB、MB2及腭根根管口间距离以及MB、MB2根管口分别到腭根根管口连线夹角,并比较不同性别间差异。结果本研究观察了279颗上颌第一磨牙,其中存在MB2牙齿233颗,检出率为83．5％,不同性别间差异无统计学意义（P〉0．05）。不同类型的根管出现概率不同,各类型出现率男女间无差异。MB与MB2根管口间距男性为（2．195±0．504）mm,女性为（1．966±0．419）mm,差异有统计学意义（P〈0．05）。结论上颌第一磨牙MB2发生率高,不同类型MB2发生概率不同,男性与女性之间无差异。MB与MB2根管口间距在两性之间存在统计学差异。     

A six-canal maxillary first molar: case report

AIM: The aim of this case report is to describe an unusual six-canal maxillary first molar tooth. CASE REPORT: The maxillary left first molar of a young African-American male was treated as an emergency at the first visit. At the second visit, the five canals (MB1 and 2, Pal1 and 2 and DB) were easily identified at high magnification of 16-25 under an operating microscope. The canals were then instrumented and filled using the Microseal technique. A careful radiographic examination of the final fill indicated that there was a third canal in the palatal root as suggested by a slight extrusion of the filling material between the two canals. At the third visit, the fillings of the palatal canals were removed and the apical 4mm was re-examined. The existence of a third palatal canal exiting between the two apices was verified and subsequently instrumented and obturated. KEY LEARNING POINTS: It should be assumed that all molar teeth have more than the traditionally expected three canals. The location of root canals should be identified at high magnification under the microscope. Careful radiographic re-examination of the fillings should be done in order to identify possibly missed canals.     

上颌第一磨牙近中颊根三根管1例

上颌第一磨牙近巾颊根三根管较少见,本文介绍1例近中颊根存在3个根管的上颌第一磨牙,3个根管口相距约1.5 mm,根管长度基本正常.     

上颌第一磨牙远颊双根管1例

上颌第一磨牙根管系统复杂多样,近颊根双根管发生率较高,而远颊根少有双根管报道。本文报道1例具有5根管的上颌第一磨牙（其中近颊及远颊根各2个根管）。     

A study of the distobuccal root canal orifice of the maxillary second molars in Chinese individuals evaluated by cone-beam computed tomography

As is commonly understood, the root canal morphology of the maxillary molars is usually complex and variable. It is sometimes difficult to detect the distobuccal root canal orifice of a maxillary second molar with root canal treatment. No literature related to the distobuccal root canals of the maxillary second molars has been published.

Objective

To investigate the position of the distobuccal root canal orifice of the maxillary second molars in a Chinese population using cone-beam computed tomography (CBCT).

Material and methods

In total, 816 maxillary second molars from 408 patients were selected from a Chinese population and scanned using CBCT. The following information was recorded: (1) the number of root canals per tooth, (2) the distance between the mesiobuccal and distobuccal root canal orifice (DM), (3) the distance between the palatal and distobuccal root canal orifice (DP), (4) the angle formed by the mesiobuccal, distobuccal and palatal root canal orifices (∠ PDM). DM, DP and ∠ PDM of the teeth with three or four root canals were analyzed and evaluated.

Results

In total, 763 (93.51%) of 816 maxillary second molars had three or four root canals. The distance between the mesiobuccal and distobuccal orifice was 0.7 to 4.8 mm. 621 (81.39%) of 763 teeth were distributed within 1.5-3.0 mm. The distance between the palatal and distobuccal orifice ranged from 0.8 mm to 6.7 mm; 585 (76.67%) and were distributed within 3.0-5.0 mm. The angle (∠ PDM) ranged from 69. 4º to 174.7º in 708 samples (92.80%), the angle ranged from 90º to 140º.

Conclusions

The position of the distobuccal root canal orifice of the maxillary second molars with 3 or 4 root canals in a Chinese population was complex and variable. Clinicians should have a thorough knowledge of the anatomy of the maxillary second molars.     

上颌第一磨牙腭侧双根双管2例

上颌第一磨牙腭侧双根双管较少见。本文报道2例腭侧双根双管的上颌第一磨牙及其治疗方法,提示正确全面的髓腔入口的设计以及仔细的探查对于非典型解剖结构根管的发现有很大的帮助。     

C-shaped root canal configuration in maxillary first molars

AIM: This clinical report presents the endodontic treatment of two maxillary first molars and the anatomical study of two additional maxillary first molars with a C-shaped distally located root canal system. This configuration is not a common finding. SUMMARY: According to the endodontic literature, the C-shaped root canal is most frequently seen in the mandibular second molar. The occurrence of C-shapes in maxillary first molars, however, has only been described in a limited number of case reports. We observed this configuration in two out of 2175 root-filled maxillary first molars treated at the Department of Endodontology, Ghent University Hospital, during the last 10 years. In order to study and visualize this particular aberration, cross-sections in two additional two-rooted maxillary first molars were made. From these cross sections it can be concluded that the C-shaped canal configuration is the result of a fusion of the distobuccal and the palatal roots.     

Root canal morphology of the mesiobuccal root of maxillary first molars: a micro-computed tomographic analysis

Aim  To investigate ex vivo , the root canal morphology of the MB root of maxillary first molar teeth by means of micro-computed tomography.
Methodology  Thirty extracted intact human maxillary first molar teeth were selected for micro-tomographic analysis (SkyScan 1072, Aartselaar, Belgium) with a slice thickness of 38.0 μm. The following data regarding the MB root were analysed and recorded: number and type of root canals, prevalence of isthmuses, prevalence of intercanal connections, presence of accessory canals, presence of loops and number of apical foramina.
Results  The MB2 canal was present in 80% of specimens and was independent in 42% of these cases. When present, the MB2 canal merged with the MB1 canal in 58% of cases. Communications between the two canals were found in all specimens, with isthmuses in 71% of the cases. These communications and isthmuses were respectively in 42% and 54% of the cases in the coronal third, in 59% and 79% of the cases in the middle third and in 24% and 50% of the cases in the apical third. A single apical foramen was found in 37% of specimens, two apical foramina were present in 23% of the cases, with three or more separate apical foramina occurring in 40% of the specimens.
Conclusions  The MB root canal anatomy was complex: a high incidence of MB2 root canals, isthmuses, accessory canals, apical delta and loops was found.     

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.     

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.     

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。     

Symmetry of root anatomy and root canal morphology in maxillary premolars analyzed using cone-beam computed tomography

ObjectiveThis study aimed to use cone-beam computed tomography (CBCT) to evaluate the root anatomy and canal morphology of maxillary premolars in a Chinese population and determine their degree of bilateral symmetry.Design774 CBCT images were retrospectively analyzed, representing 1387 maxillary first premolars and 1403 second premolars. The number of roots and canals were recorded. The morphology of root canal systems was determined according to Vertucci’s classification. The symmetry of root and canal anatomies between maxillary contralateral premolars was further evaluated.ResultsThe most common anatomy of maxillary first and second premolars was one-rooted with two canals (58.0%) and one-rooted with one canal (50.3%), respectively. The typical canal morphology was type IV (42.7%) in maxillary first premolars and type I (50.3%) in maxillary second premolars. One-rooted maxillary premolars exhibited a higher variability in the canal morphology, compared to two-rooted or three-rooted teeth. Maxillary second premolars exhibited greater anatomic symmetry than first premolars. The root and canal numbers showed bilateral symmetry between 80.2% of maxillary first premolar pairs and 81.8% of second premolar pairs. Bilateral symmetry in both number and morphology of roots and canals was observed for 72.3% of maxillary first premolar pairs and 73.2% of second premolar pairs.ConclusionThe root anatomy and canal morphology of maxillary premolars in a Chinese population were quite diversified. Maxillary contralateral premolars demonstrated a high degree of symmetry in root and canal anatomies, which enables practitioners to better determine the nature of the root canal system during treatment of opposite homonymous teeth.     

上颌第二磨牙弯曲单根单根管1例

上颌第二磨牙单根单根管发生率低,弯曲单根单根管更罕见.本文报道1例弯曲单根单根管上颌第二磨牙,并使用锥形束CT评估其三维根管形态.     

An unusual maxillary first molar with four roots and six canals: a case report

This case report presents an unusual maxillary right first molar with four roots and six canals. Endodontic treatment was provided and final restoration was accomplished with composite resin. Treating extra canals in maxillary first molars may be challenging. Inability to find and properly treat the root canals may cause failures. Complete clinical and radiographic examination and a thorough knowledge of the morphology of these teeth is necessary for successful clinical results.     

云南地区人群下颌第一前磨牙、第二前磨牙和第一恒磨牙根管解剖形态的锥形束CT分析

目的利用锥形束CT（CBCT）分析云南地区人群下颌第一前磨牙、第二前磨牙和第一恒磨牙根管解剖形态,为临床根管治疗提供理论依据和参考。 方法根据年龄（20 ~ 29岁、30 ~ 39岁、40 ~ 49岁、50 ~ 59岁）分层抽取2017年1月至2018年1月在昆明医科大学附属口腔医院放射科进行CBCT检查的患者的数据资料各100例。400例患者中有324例CBCT数据资料符合标准,其中男166例、女158例,年龄20 ~ 29岁82例、30 ~ 39岁82例、40 ~ 49岁82例、50 ~ 59岁78例。统计分析下颌第一前磨牙、第二前磨牙和第一恒磨牙的根管数目、根管长度和根管弯曲度,并对不同年龄段根管长度、下颌第一磨牙牙尖到根分叉距离及根尖孔到下颌神经管距离数据进行单因素方差分析,对不同性别下颌第一磨牙牙尖到根分叉距离及根尖孔到下颌神经管距离数据进行独立样本t检验。 结果通过对324例患者CBCT影像资料的分析得出,下颌前磨牙基本为单根管（647/648颗）,仅见1例右下第一前磨牙双根管。下颌前磨牙弯曲度以一级弯曲（5° ~ 10°）和二级弯曲（10° ~ 25°）为主,前磨牙根管长度大多处于正常范围（15 ~ 25 mm）,下颌第一恒磨牙弯曲度近远中根均以二级弯曲（10° ~ 25°）为主,下颌第一恒磨牙牙尖到根分叉的距离随年龄增长变短（F_左侧=11.16,P_左侧<0.001;F_右侧=11.51,P_右侧<0.001）,男女性别差异无统计学意义（t_左侧=1.31,P_左侧=0.19;t_右侧=0.51,P_右侧=0.61）;下颌第一恒磨牙根尖孔到下颌神经管的距离随年龄增长变长（F_左侧=7.03,P_左侧<0.001;F_右侧=12.25,P_右侧<0.001）,男女性别差异无统计学意义（t_左侧=-0.64,P_左侧=0.52;t_右侧=-0.11,P_右侧=0.91）。 结论本研究中云南地区人群下颌前磨牙根管解剖形态相对简单;下颌第一恒磨牙根管解剖形态复杂,云南地区人群下颌前磨牙、第一恒磨牙根管解剖系统与其他地区相比有所差异,但增龄性变化无区别,CBCT可为临床根管治疗提供依据。     

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。     

上颌第一磨牙近中颊根的解剖形态研究

目的：研究上颌第一磨牙（16、26）近中颊根的解剖形态，为临床治疗提供参考。方法：使用透明标本法，将132个离体16、26制成透明牙，观察其近中颊根的牙根外形与根管形态，比较并分析两者间的关系。结果：16、26近中颊根的牙根外形按照融合角度和分叉情况的不同分为4型：Ⅰ～Ⅳ型牙根的百分比依次为40.91％、23．48％、23．48%和12．12％。根管形态按Weine法分为4型：1-1型、2—1型、1—2型、2—2型，发生率依次为32．58％、17．42％、12．12％和37．88％。并对根管的锥度和弯曲角度进行了探讨。结论：16、26近中颊根的牙根外形与根管形态间有着密切的关系，掌握其形态学规律具有重要的临床意义。