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.     

Three Root Canals in the Mesiobuccal Root of Maxillary Molars: Case Reports and Literature Review

Introduction

The knowledge of root canal anatomy is essential to ensure a successful outcome of surgical and nonsurgical root canal treatment. The aims of this article were to present 2 cases of maxillary molars with 3 mesiobuccal root canals and to review the available literature on this anatomic variation.

Methods

The first case described a nonsurgical root canal treatment of tooth #16 in a 29-year-old man with the aid of a dental operating microscope. In the second case, an extracted maxillary right first molar was scanned by a micro–computed tomographic system and reconstructed 3-dimensionally using modeling software.

Results

In both cases, the mesiobuccal root had 3 canals (type 3-2 in case I and type 3-3 in case II), whereas the distobuccal and palatal roots had a single canal. The literature review showed that the overall incidence of 3-canaled mesiobuccal roots in maxillary molars ranged from 1.3%–2.4% and that the most common root canal configuration was type 3-2.

Conclusions

Clinicians should always anticipate the presence of extra canals in maxillary molars and use all the available tools to locate and treat these.     

Root and Root Canal Morphology in Maxillary Second Molar with Fused Root from a Native Chinese Population

Introduction

Root fusion is an anatomic variation in maxillary second molars (MSMs); however, the nature of this canal morphology as it relates to its root anatomy has not been fully clarified. The purpose of this study was to investigate the relationship between features of fused roots and root canal anatomy in MSMs using micro–computed tomographic imaging.

Methods

One hundred eighty-seven extracted MSMs were scanned with the μCT50 (Scanco Medical, Bassersdorf, Switzerland), and their root and canal morphology was classified and analyzed using the classifications proposed by Yang and Vertucci. The number and position of canals that merged were recorded and compared among different root fusion types.

Results

One hundred eight (57.75%) MSMs had 3 separate roots, and 79 (42.25%) had fused roots. Of the 79 fused roots, 22 showed partial canal merging, and 6 had complete canal merging. Canal merging was found with teeth with 3-root fusion more often than in those with 2-root fusion (P < .05). Of 28 merged canals, 16 occurred between mesiobuccal and distobuccal canals and 9 among mesiobuccal, distobuccal, and palatal canals.

Conclusions

MSMs with fused roots may present a complicated root canal system as a result of canal merging.     

A Rare Root Canal Configuration of Bilateral Maxillary First Molar with 7 Root Canals Diagnosed Using Cone-beam Computed Tomographic Scanning: A Case Report

Introduction

The complexity of the root canal system of maxillary molars presents a constant challenge in the diagnosis and treatment of these teeth. This case report describes the importance of a surgical operating microscope and cone-beam computed tomographic (CBCT) imaging.

Methods

Root canal treatment of a left maxillary first molar with 3 roots and 7 canals was successfully performed. Seven canals were identified with the help of a surgical operating microscope and CBCT imaging. CBCT images also confirmed the 3 roots and 7 canals in the right maxillary first molar.

Results

CBCT images confirmed a type IV canal pattern in the distal and palatal root, whereas the mesial root had a type VIII canal pattern.

Conclusions

The use of a surgical operating microscope and CBCT imaging helps the clinician to diagnose unusual anatomy of a tooth and facilitate successful endodontic treatment.     

Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan population

AIM: To investigate the root and canal morphology of permanent maxillary molar teeth from a Ugandan population. METHODOLOGY: Maxillary first (n = 221) and second molar (n = 221) teeth were collected from patients attending dental clinics in Kampala. Teeth were prepared using a clearing technique: the pulp chambers were accessed and the teeth placed consecutively into 5% sodium hypochlorite, 10% nitric acid, then methyl salicylate. Indian ink was injected into the pulp chambers to demonstrate the canal system. RESULTS: In the first molars, 95.9% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 3% of specimens and with the distobuccal root in 0.5% of teeth. In the second molars, 86% of the teeth had separate roots. The mesiobuccal root was fused with the palatal root in 6.3% of specimens and with the distobuccal root in 6.8% of teeth. Apical deltas were more frequent in the mesiobuccal root when compared with distobuccal and palatal roots of both the first and second molars. A type I canal configuration (>75%) was the most frequent in all the roots of both the first and second molars. Canal intercommunications and lateral canals were more frequent in the mesiobuccal root when compared with other roots. CONCLUSIONS: The mesiobuccal root tended to have more variations in the canal system followed by the distobuccal root, whereas the palatal root had the least. The findings in root and canal morphology of this Ugandan population were different from previous studies, which may partly be attributed to racial differences.     

Endodontic management of a maxillary first molar with eight root canal systems evaluated using cone-beam computed tomography scanning: a case report

Introduction

Root canal treatment of maxillary molars presenting with complex root canal configurations can be diagnostically and technically challenging.

Methods

Nonsurgical endodontic therapy of a left maxillary first molar with three roots and eight root canals was successfully performed. This unusual morphology was diagnosed using a dental operating microscope (DOM) and confirmed with the help of cone-beam computed tomography (CBCT) images.

Results

CBCT axial images showed that both the mesiobuccal and distobuccal root contained a Sert and Bayirli type XV canal, whereas the palatal root showed a Vertucci type II canal configuration.

Conclusions

The use of a DOM and CBCT imaging in endodontically challenging cases can facilitate a better understanding of the complex root canal anatomy, which ultimately enables the clinician to explore the root canal system and clean, shape, and obturate it more efficiently.     

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。     

The root and root canal anatomy of maxillary molars in a Chinese population

Abstract The purpose of this investigation was to study the prevalence of fused roots, C-shaped roots, C-shaped root canal orifices and C-shaped root canals in the maxillary molars of a Chinese population. A total of 305 first molars and 309 second molars were collected in Taiwan. The teeth were demineralized and placed in methyl salicylate to make them transparent. Root fusion was examined and the pulp chamber floor was checked for C-shaped orifices. Chinese ink was then injected into the root canal system to demonstrate possible C-shaped canals. The maxillary first molars had the palatal root fused with the mesiobuccal root in 0.3% of the cases, and with the distobuccal root in 2.0%. Teeth with C-shaped roots existed in only 0.3% of maxillary first molars, while 6.2% of the maxillary first molars and 40.1% of the maxillary second molars had fused roots. The maxillary second molars had the palatal root fused with the mesiobuccal root in 18.1% and with the distobuccal root in 2.6%; the palatal root was fused with the mesiobuccal and distobuccal root in 8.1% of the material. The maxillary second molars had a C-shaped root in 4.5% and C-shaped root canal orifices with C-shaped root canals in 4.9% of the cases. Fused roots or incompletely separated roots are common in the maxillary second molars amongst Chinese people, while C-shaped roots and root canals in maxillary molars are not frequently seen.     

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。     

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.     

Root and canal morphology of Thai maxillary molars

AIM: To investigate the root and canal morphology of 268 maxillary 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 root; (iii) root-canal configuration in each root using Vertucci's classification with additional modifications; and (iv) presence and location of lateral canals and intercanal communications. RESULTS: All the maxillary first and second molars had three separate roots. Only, half (51%) of the maxillary third molars had three separate roots; the other half had fused or conical roots. The majority of the distobuccal (98.1-100%) and palatal (100%) roots had type I canals. Over half of the mesiobuccal roots of first (65%) and second (55%) molars had two canals. The most common (44.2%) canal configuration in mesiobuccal roots of first molars was type IV (two canals, two foramina). A variety of canal types were found in the mesiobuccal roots of second molars. Maxillary third molars showed the greatest diversity of canal morphology. There was an increase in the prevalence of lateral canals towards the apical part of the roots and intercanal communications were present in 16% of each of first, second and third Thai maxillary molars. CONCLUSIONS: The mesiobuccal roots of Thai maxillary molars possessed a variety of canal system types. Over 50% of the first molars had a second mesiobuccal canal. The palatal and distobuccal canals mainly had type I canals. Only, a small proportion (7.3-13.3%) of the roots exhibited lateral canals which were the most common in the apical third     

Clinically Relevant Dimensions of 3-rooted Maxillary Premolars Obtained Via High-resolution Computed Tomography

Introduction

This study aimed to characterize the dimensions of a selection of 3-rooted maxillary premolars through high-resolution computed tomographic analysis considering measures of clinical interest for root canal treatment, such as root wall thickness, canal diameters, and distances between 2 canals in fused roots and between the root apex and foramen.

Methods

Fifteen 3-rooted human maxillary premolars extracted for therapeutic reasons were individually scanned using a high-resolution desktop high-resolution computed tomographic system. Starting from the apical foramen, the selected cross-sectional images corresponding to each millimeter of the roots were evaluated. Measures of clinical interest were determined using Image J software (version 1.41; National Institutes of Health, Bethesda, MD).

Results

Root wall thickness as thin as 0.4 and 0.6 mm was detected in the apical portion of buccal and palatal roots, respectively. In the cervical portion, buccal roots had narrower root walls (0.817–1.670 mm) compared with palatal roots (1.361–2.720 mm). In all thirds, the palatal canal was wider compared with the mesiobuccal and distobuccal canals. In the buccopalatal direction, all roots had thicker root walls toward the furcation, whereas in the mesiodistal direction the mesiobuccal and distobuccal roots had the thinnest walls along their distal and mesial aspects, respectively. Both buccal canals revealed dentin apposition 2 mm from the canal orifice, resulting in cervical constriction. Generally, the distance between the root apex and the foramen was greater in distobuccal roots in comparison with the others with a tendency for foramina to be eccentric.

Conclusions

Three-rooted premolars are a clinical challenge not just because of their low frequency and difficulties regarding diagnosis and root canals access but also because of their fragile roots. These phenomena are critical in terms of the amount of dentin removed during the preparation of root canals and during post space preparation.     

Root and root canal morphology of the human permanent maxillary first molar: a literature review

The objective of this study was to review the literature with respect to the root and canal systems in the maxillary first molar. Root anatomy studies were divided into laboratory studies (in vitro), clinical root canal system anatomy studies (in vivo) and clinical case reports of anomalies. Over 95% (95.9%) of maxillary first molars had three roots and 3.9% had two roots. The incidence of fusion of any two or three roots was approximately 5.2%. Conical and C-shaped roots and canals were rarely found (0.12%). This review contained the most data on the canal morphology of the mesiobuccal root with a total of 8399 teeth from 34 studies. The incidence of two canals in the mesiobuccal root was 56.8% and of one canal was 43.1% in a weighted average of all reported studies. The incidence of two canals in the mesiobuccal root was higher in laboratory studies (60.5%) compared to clinical studies (54.7%). Less variation was found in the distobuccal and palatal roots and the results were reported from fourteen studies consisting of 2576 teeth. One canal was found in the distobuccal root in 98.3% of teeth whereas the palatal root had one canal in over 99% of the teeth studied.     

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.     

Root canal morphology of the mesiobuccal root in maxillary first molars of a Jordanian population

This in vitro study investigated the presence of second (MB2) root canals and the number of apical foramina found in mesiobuccal roots of the permanent maxillary first molars; in addition, the study evaluated the effectiveness of magnification to detect MB2 canals. One hundred extracted maxillary first molars were collected from Jordanian patients. The number of roots (as well as their morphology) was investigated. The number of canal orifices in mesiobuccal root was assessed, with and without magnification, and findings were compared. The number of apical foramina and the distance between mesiobuccal and second canal orifices were investigated under magnification. Of the 97 specimens that were subject to additional investigation, all teeth had three separated roots, except for three specimens that had either mesiobuccal or distobuccal roots fused with the palatal root. The number of MB2 canals that were detected increased from 55 (56.7%) to 61 (62.9%) teeth when magnification was used. Within the limits of this in vitro study, it was concluded that the Jordanian population had a high percentage of MB2 canals in the mesial buccal roots. Moreover, the use of clinically used magnifying devices increased the number of MB2 canals detected.     

A Cone-beam Computed Tomographic Study of Root and Canal Morphology of Maxillary First and Second Permanent Molars in a Thai Population

Introduction

Understanding tooth anatomy is crucial for effective endodontic treatment. This study investigated the roots and root canal morphology of maxillary first and second permanent molars in a Thai population using cone-beam computed tomographic (CBCT) imaging.

Morphology of Mandibular First Molars Analyzed by Cone-beam Computed Tomography in a Korean Population: Variations in the Number of Roots and Canals

Introduction

The aim of this study was to determine the root and canal morphology of the mandibular first molars in a Korean population of Mongolian origin by retrospective analysis of a large number of cone-beam computed tomography (CBCT) images.

Methods

A total of 976 subjects with bilateral mandibular first molars were examined by using in vivo CBCT methods. The number and configuration of roots, the number of root canals, and the canal configuration based on Vertucci's classification were determined.

Results

Overall, 25.82% of examined molars had 3 roots, 73.51% had 2 roots, and 0.67% had 1 root. The incidence of fourth canal was 50.36%. A right-sided predominance was noted for extra distal roots (P < .001), whereas a left-sided predominance was observed for extra distal canals (P < .001). No significant sex-related differences were shown for their prevalence. The bilateral prevalence rate was 69.13% for extra distal roots and 78.08% for extra distolingual (DL) canals. In the mesial roots, type IV canal was the most frequent (76.86% for 2-rooted molars and 72.96% for 3-rooted molars). In the distal roots, type l was the most common (66.62% for 2-rooted molars and 99.40%–100% for 3-rooted molars). The incidence of 2 canals in distobuccal roots, first reported in this study, was 0.15%.

Conclusions

Among mandibular first molars, there is a high prevalence of a separate DL root and/or a separate DL canal, and such molars commonly have 4 canals in the Korean population. CBCT is a useful tool for determining root and canal morphology.     

Prevalence of Second Mesiobuccal Canals in Maxillary First Molars Detected Using Cone-beam Computed Tomography,Direct Occlusal Access,and Coronal Plane Grinding

Introduction

The purpose of this study was to determine the prevalence of the second mesiobuccal canal (MB2) in 100 maxillary first molars using 3 independent methods and a combination method.

上颌第二磨牙近颊融合根中MB2的锥束CT研究

目的:通过锥束CT技术研究上颌第二磨牙近颊融合根中MB2的发生率。方法:收集199例患者的上颌第二磨牙CBCT数据,观察牙根融合类型、年龄以及牙位对MB2发生的影响。结果:199例患者共有380颗上颌第二磨牙,其中145颗牙的近中颊根与其他牙根融合;近远中颊根融合型(Ⅰ型)和近中颊根腭根融合型(Ⅱ型)的MB2发生率分别是5.5%、41.9%,而全融合型(Ⅲ型)则未发现MB2,Ⅰ、Ⅲ型融合的MB2发生率低于Ⅱ型;随着年龄增大,MB2发生率降低;181例具有双侧上颌第二磨牙的患者中,左右两侧融合根及MB2的发生率无显著差异。结论:上颌第二磨牙近中颊根与其他牙根融合时,其MB2发生率会出现变异。     

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.