The maxillary second molar: variations in the number of roots and canals

Maxillary Dental Anatomy and Physiology: Endodontic and Periodontal

The maxillary sinus floor is formed by the alveolar process of the maxilla. Frequently, the roots of maxillary molars and premolars may protrude into the sinus cavity, with only a thin membrane separating them. Endodontic infections are characterized by mixed biofilms of anaerobic and proteolytic bacteria that can infect the root canal space and accessory anatomy of those teeth producing apical periodontitis. Due to the close relationship with the maxillary sinus, the persistence of apical periodontitis could potentially lead to odontogenic sinusitis. Understanding maxillary sinus anatomy and its relationship with the posterior maxillary dentition is crucial for diagnosing this entity.

Cone beam computed tomography analysis of the root and canal morphology of the maxillary second molars in a Syrian subpopulation

AIM

To investigate the root number and morphology of the maxillary second molars in the Syrian population besides bilateral symmetry, and the effect of gender.

METHODS

250 Cone Beam Computed Tomography (CBCT) images (140 females, 110 males) were examined by two endodontists. The detailed analysis included the number of roots, the number of canals and their configurations, bilateral symmetry, and relation to gender. The evaluation was made according to Vertucci classification by analyzing the CBCT images at all levels (Axial, Coronal, Sagittal, Oblique, and 3D). The Chi-square statistical analysis was performed to compare the canals' morphologies and bilateral symmetry in both genders via SPSS.

RESULT

The most common shape of the upper second molars is three roots (90.4%). There were significant differences between males and females regarding the symmetry of the number of roots (P < 0.05). The root canal configuration was mainly Vertucci type I classification in the Distobuccally (93.4%) and palatal root (99.6%). The most common type in the mesial root was type I (29.5%), showing all varieties of Vertucci classifications (except VII, and VIII) percentage of MB2 of 70.5%. The ratio of symmetry was (59.6%) with no significant statistical difference between the genders (P = 0.708).

CONCLUSION

Most maxillary second molars in the examined Syrian population were types (II) (associated with MB2 cases with three roots and four canals). In terms of symmetry, the number of roots surpassed the canal configuration. Males had a greater symmetrical tendency in the number of roots than females.

Worldwide Prevalence of Single-rooted with a Single Root Canal and Four-rooted Configurations in Maxillary Molars: A Multi-center Cross-sectional Study with Meta-analysis

INTRODUCTION

To evaluate the prevalence of single root with a single root canal and four-root configurations in the maxillary first and second molars, and analyze how geographic region, ethnicity, sex, and age impact these outcomes.

METHODS

Researchers from 44 nations examined 26,400 maxillary molars using cone-beam computed tomography scans to gather data on the proportions of single roots with single canals and four-root configurations. All observers underwent prior calibration regarding the step-by-step assessment protocol and anatomical concepts to ensure consistent evaluations across all assessed locations. Tests were conducted to evaluate the intraobserver and interobserver reliability. Demographic data including ethnicity, gender, and age were collected for each participant. The potential impact of imaging voxel size and field-of-view on bias was also assessed. The primary results were depicted as odds ratios and untransformed proportion forest plots with 95% confidence intervals. Additionally, a meta-analysis was performed to compare various subgroups and identify sources of variation among them. Statistical significance was set at 5%.

RESULTS

The prevalence of single-rooted with a single canal and four-rooted configurations in the maxillary first molar was 0.16% and 0.28%, respectively, while in the maxillary second molar, it was 2.56% and 0.83%. Males tended to exhibit lower percentages of single roots with a single canal (P < .05) and higher percentages of four-rooted configurations (P > .05) in the second molar, whereas the African subgroup displayed lower proportions for both configurations. Additionally, in both teeth, single roots with a single canal were more prevalent among older patients. Voxel size and field-of-view did not significantly influence the results (P > .05).

CONCLUSIONS

The proportions of single-rooted with a single canal and four-rooted configurations were low, and demographic factors such as geographic region, ethnicity, sex, and age may have influenced the outcomes for the maxillary second molar.

Diving Deep: Exploring Dual Palatal Canals in the Upper Second Molar

Dental anatomy exhibits considerable variation with the presence of additional canals being a common occurrence. The upper second molar typically presents with three canals and three roots; however, variations such as the existence of an extra canal or a root can pose challenges during endodontic treatment. Maxillary molar is characterized by an additional canal located within the palatal root, often exhibiting complex configurations and variations in morphology. Access refinement is critical to gaining adequate visibility and facilitating instrumentation. Meticulous exploration of the pulp chamber floor and careful examination of radiographs from different angles are essential for accurate diagnosis. Careful negotiation and cleaning of the extra canal with appropriate files and irrigants are essential to remove pulp tissue and debris effectively. Furthermore, obturation of the canal space with biocompatible materials is crucial to ensure a three-dimensional seal and prevent bacterial ingress. Clinically, the inability to detect and treat the extra palatal canal can lead to persistent infection, incomplete debridement, and compromised treatment outcomes. This case report delves into the significance of this anatomical variation, diagnostic modalities, and effective management strategies.

Root and canal morphology of maxillary second molars in a Black South African subpopulation using cone-beam computed tomography and two classifications

This study investigated the root and canal morphology of maxillary second molars in a Black South African population using high-resolution cone-beam computed tomography. In total, 386 maxillary second molar teeth were evaluated and described according to the classifications of Vertucci (with the additions of Sert and Bayirli), as well as Ahmed et al. Root number, fusions and canal morphology were recorded. Relationships between morphology, sex and age were assessed using Fisher's exact test (p < 0.05). Maxillary second molars were predominantly three-rooted (96.1%), with root fusion observed in 14%. No relationships between sex, age and canal morphology were found. Additional canals were observed in 67.4% of mesiobuccal roots. The Ahmed et al. classification provided a better overall description of the morphology. In this population, maxillary second molar teeth exhibited a diversity of root and canal morphology. Complex variations may render endodontic management more difficult and increase the possibility of missed anatomy.

Endodontic management of a rare case of the geminated maxillary second molar tooth using CBCT

This report illustrates a rare case of a geminated maxillary right second molar tooth using CBCT in a 23-year-old man with severe pain. Nonsurgical endodontic treatment was performed, which gave rise to an asymptomatic tooth at the 12-month follow-up.

Comparison of Obturation Quality after MTA Orthograde Filling with Various Obturation Techniques

This study aimed to quantify and compare the obturation quality after mineral trioxide aggregate (MTA) orthograde fillings with three different obturation techniques. Thirty-three extracted human maxillary molars were collected. Distobuccal and palatal canals were prepared to an apical size of #40/06 with a Profile Ni-Ti system. All 66 canals were divided into two groups according to the material (EZ-seal or OrthoMTA) and then obturated using three different techniques: manual compaction using S-kondenser (group H), compactor activation (group C), or reverse rotary motion of Ni-Ti file (group R). The obturated roots were scanned using micro-computed tomography (micro-CT). The percentage of voids located in the apical 5 mm was measured separately, that is, closed, open, and total porosity. There was no relation between the filling material and obturation technique (p > 0.05). The percentage volume of open and total porosity was higher in EZ-seal than in OrthoMTA (open: p = 0.002, total: p = 0.001). Group H showed higher open and total porosity than groups C and R. Micro-CT analysis showed that the void volume after orthograde MTA fillings significantly decreased when the additional activation was accompanied by hand condensation. Obturation with a Ni-Ti file using reverse motion could be recommended as an MTA orthograde filling technique.

Root canal morphology of maxillary second molars in a Saudi sub-population: A cone beam computed tomography study

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Most of the scans showed three roots (92%), while two roots is (6.6%), four roots is (1.1%), and one root is (0.3%).

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Males and females showing greater tendencies for three and two roots, respectively.

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There was no differences between teeth sides.

Introduction

Root morphology and canal anatomy of maxillary molars shows several complexities and variations. Knowledge of these is essential for successful endodontic treatment. This study aimed to investigate the morphology of the maxillary second molars in a Saudi Arabian sub-population in relation to gender, age, and nationality, as well as to analyze the anatomical symmetry between the left and right side in each individual.

Methodology

420 digitized cone-beam computed tomography (CBCT) scans were collected, of which 351 scans met the inclusion criteria. Number of roots and canals at three different levels of the root in each case was counted at all available sides and compared on the basis of the study variables. Statistical significance was set at P ≤ 0.05.

Results

Most of the patients (n = 323, 92%) had three roots, while two roots (n = 23, 6.6%), four roots (n = 4, 1.1%), and one root (n = 1, 0.3%) were less frequently observed. A significant correlation between female patients and the presence of two canals, while male patients showed a higher correlation with the presence of four canals at all levels. There also was a correlation between Saudi participants and the presence of four canals at all levels. No significant correlation in symmetry between the left and right side root canal anatomy was found. There was an inverse relation between the number of canals and age.

Conclusion

Considering the limitations in this study, it appears that the Saudi population is more likely to have three- and two-rooted maxillary second molars, with males and females showing greater tendencies to having three and two roots, respectively.

Cone Beam Computed Tomography-aided Endodontic Management of Second Maxillary Molar with Two Separate Palatal Roots: A Case Report

An infected human root canal system harbors harmful microbiota that needs to be eliminated by root canal therapy. But the human root canal system is known to have a complex anatomy. Hence, the knowledge of a possibly aberrant anatomy is deemed necessary before carrying out a root canal therapy. Usually, the maxillary second molars have three roots and three or four root canals (a second mesiobuccal canal as the fourth canal). The presence of a second palatal root and a second palatal root canal is very rare (1.4% incidence). Failure to locate and treat such aberrant external and internal anatomy results in a compromised root canal therapy. With the introduction of advanced imaging and visualization techniques such as cone beam computed tomography (CBCT) and dental operating microscopes, the variations in root anatomy have been successfully detected and treated. This case report describes the endodontic management of a second maxillary molar with two palatal roots and four separate canals, performed with the help of CBCT.

Endodontic Management of Maxillary Second Molar Tooth with a Single Root and Single Canal

Comprehensive understanding of variations in the root canal morphology of a maxillary molar is useful for performing successful endodontic treatment in such cases. This case report describes endodontic management of a case with such aberrant root canal morphology of a maxillary second molar having a single root and single canal.

Analysis of root canal system of maxillary first and second molars and their correlations by cone beam computed tomography

BACKGROUND/PURPOSE

Understanding the root canal systems of molars and the association of root canal system in adjacent or contralateral molars is important for dental practice. This study aimed to use cone-beam computed tomography (CBCT) to analyze the morphology similarity of root canal systems in the maxillary first and second molars.

METHODS

CBCT images of 1741 maxillary molars in a total of 519 patients were blindly examined to analyze the correlation of root canal systems between maxillary first and second molars as well as the bilateral first and second molars.

RESULTS

The most common type in maxillary first molars is 3R4C (3 roots/4 canals), whereas in maxillary second molars is 3R3C.The symmetry in type of root canals in bilateral maxillary first and second molars were 87.36% and 79.85%, respectively. The similarities of root canal system in adjacent maxillary first and second molars were 53.07% (right side) and 52.58% (left side). The concurrence of MB2 canal in bilateral maxillary first molars is 77.8%, and 35.97% in maxillary second molars. In the 110 patients with MB2 canal in bilateral maxillary second molars, the chance of bilateral MB2 canals in their maxillary first molar is almost 100%.

CONCLUSION

Maxillary first molars have higher prevalence of 3R4C than second molars. The symmetry in bilateral maxillary molars is higher than the similarity in adjacent maxillary first and second molars. Application of CBCT analysis of root canal system can improve endodontic treatment outcomes. The correlation of root canal system between teeth is useful for genetic linkage.

Endodontic Retreatment of Maxillary Second Molar with Four Roots

The present communication describes the endodontic retreatment of a rare four-rooted maxillary second molar. A 25-year-old patient was referred to our dental practice requesting an apicoectomy because of continuous and permanent pain reaction six months after the first endodontic treatment. The sent radiograph demonstrated three filled root canals (one mesial, two distal) and four radiographically superimposing roots (two mesial, two distal). Due to the diagnosed chronic apical periodontitis and based on the visible untreated root canal, we decided to endodontically re-treat the quadrangular tooth against the referred apicoectomy. In the first session, only the previously untreated mesiopalatal root canal was mechanically prepared and filled with a corticosteroid- and tetracycline-containing paste. After two symptom-free weeks, the gutta-percha was removed from the other canals and calcium hydroxide was applied. Another two weeks later, the four root canals, whose orifices were “irregular quadrilateral” shaped on the pulp chamber floor representing Versiani Type A, were obturated. After the verification of this rare anatomy by cone beam computed tomography, the tooth was classified as Christie's radicular type II. One characteristic of this type is parallel running buccal and palatal roots, which caused a radiographic superimposition and probably led to the endodontic mistreatment in the first case.

Fused roots of maxillary molars: characterization and prevalence in a Latin American sub-population: a cone beam computed tomography study

Objectives

The upper molars generally have three roots; therefore, different combinations of fusion can occur, increasing the possibility of finding more complex root canal systems. The purpose of this study was to evaluate the prevalence and characterization of fused roots in first and second maxillary molars using cone-beam computed tomography (CBCT) in a Colombian population.

Materials and Methods

A total of 1274 teeth were evaluated, of which 534 were maxillary first molars and 740 were maxillary second molars. Axial sections were made at the cervical, middle, and apical levels to determine the prevalence of root fusion and the types of fusion.

Results

Overall, 43% of the molars (n = 551) presented some type of fused root. Root fusion was present in 23.4% of the maxillary first molars. The most frequent type of fused root was type 3 (distobuccal-palatal; DB-P) (58.9%). Root fusion was observed in 57.6% of the maxillary second molars, and the most prevalent type of fused root was type 6 (cone-shaped) (45.2%). Of the maxillary molars, 12.5% were classified as C-shaped.

Conclusion

Within the limitations of this study, there was a high prevalence of fused roots in maxillary molars in the Colombian population, mainly in the maxillary second molars. In first molars, the most common type of fused root was type 3 (DB-P) and in second molars, the most common type was type 6 (cone-shaped). Additionally, molars with root fusion presented variation at different levels of the radicular portion, with implications for treatment quality.

Maxillary second molar with four roots and five canals

In this case report, we present a maxillary second molar variant, which had two palatal roots with two canals and two buccal roots with three canals, including a second mesiobuccal canal. A 44-year-old female patient complained about a tooth crown fracture and severe pain in her right maxillary second molar. A clinical intraoral inspection and radiography were carried out on the tooth, and a diagnosis of chronic apical periodontitis was made. Four roots (two buccal and two palatal) and five canals (three buccal and two palatal) were found. The anatomical variation of the tooth was further confirmed by cone-beam computed tomography, a cone-fit procedure, and a radiograph with a shifted projection angle. Root-canal treatment was performed under an endodontic microscope.

Endodontic management of a maxillary first molar with two palatal roots: A case report

This case report describes the endodontic treatment of a maxillary first molar with two palatal roots. Both of the palatal canals had separate canal orifices and separate foramina. A cone beam computed tomography scan was taken prior to treatment to visualise any abnormalities seen on a periapical radiograph. The shaping procedure of the root canal treatment was performed using reciprocating instruments. The obturation was performed using matched gutta percha points and a resin based sealer in a warm vertical compaction manner. Complete bone healing of the periapical area was visualised on intra-oral radiographs taken one year after the treatment. No canals were unfilled nor untreated.

Management of a failed endodontic treatment for a maxillary second molar with two separate palatal roots

Complexity of root canal system and variations in internal anatomy of teeth require careful analysis of preoperative cone beam computed tomography or multiangle radiographs to locate and identify possible extra roots or canals. A fourth canal in upper molars is expected, and much effort should be made when planning the endodontic treatment to avoid missing a canal.

An original micro-CT study and meta-analysis of the internal and external anatomy of maxillary molars-implications for endodontic treatment

The aim of this work was to conduct a radiological micro-CT study and meta-analysis to determine the morphological features of the root canal anatomy of the maxillary molars. The radiological study included micro-CT scans of 110 maxillary first molars and 98 maxillary second molars. To identify articles eligible for inclusion in our meta-analysis, PubMed, Embase, and Web of Science were search comprehensively. The following data were extracted: study type (cadaveric, intraoperative or imaging), Vertucci types of canal configuration, presence/number of canals, roots, apical foramina, apical deltas, and inter-canal communications. The mesiobuccal root was the most variable with respect to canal configuration, type I being the most common configuration followed by type II and type IV. Type I was the most common canal configuration in the distobuccal and palatal root. Regarding the number of canals in the maxillary first and second molars, one canal was most prevalent in all roots of the three molars, except for the mesiobuccal root of maxillary first molar, in which two canals were most prevalent. The most prevalent number of roots in all maxillary molars was three. Knowledge of endodontic anatomy determines the parameters of root canal treatment and significantly affects the probability of success. It is therefore especially important to know the morphology of the root canal system in order to perform endodontic treatment correctly. Clin. Anat. 31:838-853, 2018. © 2018 Wiley Periodicals, Inc.

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.

METHODS

This study evaluated 476 maxillary first molars and 457 maxillary second molars receiving CBCT examination and determined the number of roots and canal morphology according to Vertucci's classification, and the prevalence of a second mesiobuccal (MB2) canal in the mesiobuccal (MB) root was correlated with sex, age, and tooth side.

RESULTS

Three roots were most commonly found in maxillary first and second molars. MB2 canals in the MB root were found in 63.6% and 29.4% of first and second molars, respectively. The most common canal morphology in the first molar MB roots was type I (36.4%) followed by type II (28.8%), and type IV (25.3%). The most common canal morphology in the second molar MB roots was type I (70.6%) followed by type II (14.6%) and type IV (7.5%). Bilateral MB2 canals in the MB roots were present in 80.93% and 82.59% of the first and second molars, respectively. There was a significant correlation between males and the prevalence of MB2 canals in first molars (P < .05).

CONCLUSIONS

CBCT imaging is useful to determine root canal morphology. The prevalence of MB2 canals is approximately 60% and 30% in first and second molars, respectively. Furthermore, bilateral MB2 canals were commonly found. Our results can help endodontists to improve endodontic treatment outcomes.

Treatment of a Maxillary Second Molar with One Buccal and Two Palatal Roots Confirmed with Cone-Beam Computed Tomography

Root canal configuration is an important subject in endodontic practice and dentists should be familiar with all possible types of root canal configuration. A forty-three year old male was referred for root canal treatment of his maxillary left second molar tooth with symptomatic irreversible pulpitis. Pre-operative radiographs showed a three rooted molar. However, after access cavity preparation two palatal and one buccal orifices were detected. The patient was informed of the unusual root canal anatomy and cone-beam computed tomography (CBCT) was ordered for precise evaluation of the anatomy. CBCT image confirmed the presence of one buccal and two palatal root canals; an exceptionally rare condition.

Evaluation of the root and canal systems of maxillary molars in Taiwanese patients: A cone beam computed tomography study

Background

This study evaluated variations in root canal configuration in the maxillary permanent molars of Taiwanese patients by analyzing patients' cone beam computed tomography (CBCT) images. Comparisons were made among these configurations and those previously reported. This information may serve as a basis for improving the success rate of endodontic treatment.

Methods

The root canal systems of 114 Taiwanese patients with bilateral maxillary first or second molars were examined using CBCT images. The number of roots, canals per root, and additional mesiobuccal (MB) canals, as well as the canal configuration were enumerated and recorded.

Results

Of the 196 maxillary first molars examined, three (1.5%) had a single root, two (1.0%) had two roots, and 191 (97.5%) had three separate roots. Out of all first molar roots examined, 44% of mesiobuccal (MB) roots had a single canal and the remainder had a second MB (MB2) canal. Of the 212 maxillary second molars examined, 16 (7.1%) had a single root, 51 (24.2%) had two roots, 143 (67.8%) had three roots, and two (0.9%) had four separate roots. For the MB roots, 92.3% of three-rooted maxillary second molars had a single canal and the remainder had an MB2 canal. In all three-rooted maxillary first and second molars, each of the distal and palatal roots had one canal.

Conclusions

The root canal configurations of the MB roots of maxillary molars were more varied than those of the distobuccal and palatal roots, and the root canal configurations of maxillary second molars were more varied than those of the first molars. These findings demonstrate CBCT as a useful clinical tool for endodontic diagnosis and treatment planning.

Maxillary Second Molar with Fused Root and Six Canals- A Case Report

One of the known aberrations in root canal morphology of maxillary second permanent molars is the presence of collateral mesiobuccal canals. This case report describes the endodontic management of a maxillary second molar that had a single fused root with six canals that was successfully managed with the aid of dental operating microscope. Six canal orifices were located namely MB1 (Mesiobuccal), MB2, MB3, DB1 (Distobuccal), DB2 and palatal. During the cleaning and shaping, instrument separation occurred at the apical third of the palatal canal which was removed with ultrasonics. After cleaning and shaping, the canals were obturated with resin sealer and laterally condensed gutta-percha. The patient was recalled for periodic review. After two years of follow up the patient remained asymptomatic. Cone Beam Computed Tomography (CBCT) evaluation revealed satisfactory periapical status.

Root and canal morphology of maxillary second molars by cone-beam computed tomography in a native Chinese population

Objective

To evaluate the root and root canal morphology of the maxillary second molars (MSMs) in a native Chinese population by cone-beam computed tomography.

Methods

Cone-beam computed tomography images of 2412 MSMs from 1294 Chinese patients were analyzed to determine the number and morphology of the roots, the root canal morphology, the bilateral symmetry, and the correlations of these parameters with sex and age.

Results

The percentage of fused roots increased with age, while the percentage of fused roots in women was higher than that in men. The percentage of second mesiobuccal (MB2) canals in MSMs with three separate roots was higher in men than women. Patients aged 31 to 40 years showed a higher prevalence of MB2 canals, while those aged ≥51 years showed the lowest prevalence of MB2 canals among both men and women. There was a significant difference in bilateral symmetry of MSMs between men and women.

Conclusion

Root fusion of MSMs increased with age, while the root canal morphology was more complex in patients of intermediate ages.

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 root 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.

Rare Root Canal Configuration of Bilateral Maxillary Second Molar Using Cone-beam Computed Tomographic Scanning

The aim of this article was to present a right maxillary second molar with an unusual root canal morphology of 4 roots and 5 canals as confirmed by cone-beam computed tomographic (CBCT) imaging. The tooth had a C-shaped mesiobuccal root (CBCT imaging revealed that the root was closer to the palate than the buccal side) with 2 canals, 2 fused distobuccal roots with 2 separate canals, and 1 normal bulky palatal root with 1 canal. After thoroughly examining the rare anatomy, root canal treatment was applied on the tooth. This article shows the complexity of maxillary second molar variation and shows the significance of CBCT imaging in the confirmation of the 3-dimensional anatomy of teeth and endodontic treatment.

Four-rooted permanent maxillary first and second molars in a northwestern Chinese population

OBJECTIVES

To detect the incidence and anatomic features of 4-rooted permanent maxillary molars in a northwestern Chinese population by using cone-beam computed tomography (CBCT).

DESIGN

A total of 725 Chinese patients with well-developed maxillary permanent first and/or second molars were examined by using CBCT. The number of roots and canals, shape, location, and division level of the roots were evaluated. Four-rooted maxillary first and second molars were classified according to modified Versiani's classification. The root length and cross-sectional diameters of 4-rooted molars were measured by the software Galileos Implant 1.7 (SICAT GmbH & Co. KG, Bonn, Germany). One way analysis of variance followed by a Newman-Keuls post hoc test was used to compare the groups in relation to the root length and diameters (P = 0.05).

RESULTS

Among 1365 maxillary first molars, only one tooth had four separated roots, whereas in second molars, 12 out of 1226 teeth (0.98%) exhibited an extra root; the incidences were 1.28% (7/549) for males and 0.74% (5/677) for females. All 4-rooted molars observed were unilateral. Out of a total of thirteen 4-rooted maxillary molars, six exhibited the type I root form, four exhibited the type II root form and one exhibited the type III root form; a type IV category (two molars) was added to Versiani's classification, which described maxillary molars with three buccal roots. A transitional root form between the typical 3-rooted form and double palatal roots was observed in six cases of 3-rooted molars. Measurements of root size showed that the diameter of the distopalatal roots was significantly larger than the extra mesiopalatal roots (P < 0.01).

CONCLUSION

The prevalence of the 4-rooted maxillary first and second molars in the Chinese population is low. They usually occurred unilaterally, and the shape, location and size of the four roots may be variable.

Root canal morphology of Chalcolithic and early bronze age human populations of El Mirador Cave (Sierra de Atapuerca, Spain)

This study provides a morphological characterization of the inner anatomy of the root canals of permanent first and second molars in Chalcolithic and early Bronze Age human fossils using cone-beam computed tomography. The general evolutionary trend in present-day human dentition is related to morphological simplification. As little is known about when this trend appeared in Homo sapiens populations, the aim of this work is to test the presence of modern radicular morphology 4,400 years ago. Fifty-four permanent first and second maxillary and mandibular molars of 17 individuals were included in the study. All maxillary first and second molars showed three separate roots. Almost all the lower molars analyzed (100% of first molars and 75% of second molars) had two separate roots. More differences in the canal system configuration were documented in the maxillary mesiobuccal roots than in the palatal or distobuccal roots. The most variable tooth in root and canal configuration is the maxillary second molar. It should be pointed out that 12.5% of the teeth analyzed showed a C-shaped root configuration.

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.

Aberration in the palatal root of the maxillary first molar

Thorough knowledge of root canal morphology is essential for the endodontic therapy. Variations in the root and root canal morphology, especially in multirooted teeth, are a constant challenge for diagnosis and management. The dentist needs to be familiar with the various root canal configurations and their variations for successful endodontic therapy. There are rare variations in canal number and configuration in maxillary molars, which could affect treatment outcome. Two lingual root structures are occasionally found on human permanent maxillary molars. One of these is the normal lingual root, which is always present, the other is a supernumerary structure which can be located either mesiolingually (radix mesiolingualis) or distolingually (radix distolingualis). The purpose of this paper is to review the literature and to demonstrate a case report which describes the successful non-surgical endodontic management of an unusual maxillary first molar with four separate roots and four canals.

Unusual root canal morphology of the maxillary second molar: a case report

Introduction. This clinical case report presents the successful endodontic treatment of a maxillary second molar that has a mandibular molar-like anatomy with no palatal root and with each of its roots containing two separate root canals. Cone-beam computed tomography (CBCT) was used to confirm this unusual anatomy. Methods. A 34-year-old male patient was referred to the Department of Endodontics at Inonu University's Faculty of Dentistry because of severe pain in his right maxillary second molar. Clinical and radiographic examinations identified unusual roots and root canals anatomy, and CBCT was planned in order to understand the nature of these variations. Cleaning and shaping procedures were performed using the crown down technique with Sybron Endo (Glendora, CA, USA) rotary instruments, and endodontic treatment was completed with gutta-percha cones and AH Plus resin sealers using the cold lateral compaction technique. Conclusions. The maxillary second molar exhibits aberrations and variations in terms of the numbers and configurations of its roots and root canals, and CBCT can be a useful imaging technique in endodontics.

Endodontic management of maxillary second molar with two palatal roots: a report of two cases

Endodontic treatment may sometimes fail because morphological features of the tooth adversely affect the treatment protocol. Maxillary second molars are recognized as usually having a single palatal root with a single palatal canal. The incidence of second palatal root in the maxillary second molar is very rare. Two cases are presented in this paper describing the endodontic management of a four-rooted maxillary second molar with two distinct palatal roots and canals and two distinct buccal roots and canals. Clinical examination and radiographs showed the presence of two palatal roots during the root canal procedure. The canals were biomechanically prepared with crown-down technique and obturated using lateral condensation technique with AH-Plus sealer.

A rare root canal configuration of maxillary second molar: a case report

A thorough knowledge of root canal morphology is a prerequisite for the endodontic therapy. The maxillary molars, especially the second molars, have the most complicated root canal system in permanent dentition. There are many variations in canal number and configuration in maxillary molars. Treatment may be unsuccessful because the dentist may fail to recognize the unusual canal configuration. The present paper describes a case of a right maxillary second molar with a canal configuration rarely reported in the literature. The tooth had four roots with four root canals, two individual palatal roots (mesiopalatal and distopalatal) with their own separate canals. The mesiobuccal and distobuccal root had normal anatomy. This paper may intensify the complexity of maxillary molar variation and is intended to reinforce clinician's awareness of the rare morphology of root canals.

Leonardo da Vinci's "A skull sectioned": skull and dental formula revisited

What can be learned from historical anatomical drawings and how to incorporate these drawings into anatomical teaching? The drawing "A skull sectioned" (RL 19058v) by Leonardo da Vinci (1452-1519), hides more detailed information than reported earlier. A well-chosen section cut explores sectioned paranasal sinuses and ductus nasolacrimalis. A dissected lateral wall of the maxilla is also present. Furthermore, at the level of the foramen mentale, the drawing displays compact and spongious bony components, together with a cross-section through the foramen mentale and its connection with the canalis mandibulae. Leonardo was the first to describe a correct dental formula (6424) and made efforts to place this formula above the related dental elements. However, taking into account, the morphological features of the individual elements of the maxilla, it can be suggested that Leonardo sketched a "peculiar dental element" on the position of the right maxillary premolar in the dental sketch. The fact that the author did not make any comment on that special element is remarkable. Leonardo could have had sufficient knowledge of the precise morphology of maxillary and mandibular premolars, since the author depicted these elements in the dissected skull. The fact that the author also had access to premolars in situ corroborates our suggestion that "something went wrong" in this part of the drawing. The present study shows that historical anatomical drawings are very useful for interactive learning of detailed anatomy for students in medicine and dentistry.

Maxillary right second molar with two palatal root canals

We report a clinical case of maxillary right second molar with two palatal root canals. The morphology is atypical because it is characterized by two palatal roots with two canals with widely separated orifices and canals. Modifications to the normal access opening and examination of the pulpal floor for additional canals are stressed.

Use of CBCT to identify the morphology of maxillary permanent molar teeth in a Chinese subpopulation

AIM

To investigate variations in root canal configuration in the maxillary permanent molar teeth of a Chinese subpopulation using cone-beam computed tomography (CBCT).

METHODOLOGY

A total of 269 patients with healthy, untreated, well-developed maxillary molars were enrolled, including those suffering facial trauma, and those who required a pre-operative assessment for implants. Radiographic examination by CBCT was conducted as part of their routine examination, diagnosis and treatment planning. Overall, 299 maxillary first and 210 maxillary second molar teeth were examined in vivo by CBCT. The number of roots, the number of canals per root, the canal configuration and the presence of additional mesiobuccal canals were recorded. Vertucci's classification for root-canal configurations was utilized.

RESULTS

All maxillary first molars had three separate roots; however, 52% of mesiobuccal (MB) roots had two canals with the remainder having one. All distobuccal and palatal roots had Vertucci Type I canal configurations. When the MB2 canal was present, 14, 69 and 16% of MB roots had Type II, IV and V canal configurations, respectively. The root canal system of the maxillary first molar teeth could be categorized into two variants: one with three separate roots with one canal in each of the distobuccal and palatal roots and two canals in the MB root, and the other with three separate roots with one canal in each root. Of 210 maxillary second molars, 10% had one root, 8% two roots and 81% three roots. Of the MB roots, 22% had two canals with the remainder having one. When the MB2 canal was present, 18%, 58%, 10% and 3% of MB roots had type II, IV, V and VI canal configurations, respectively. The root canal system of the maxillary second molar could be categorized into eight variants.

CONCLUSIONS

Mesiobucccal roots of maxillary molar teeth had more variation in their canal system than the distobuccal or palatal roots. The root canal configuration of the maxillary second molars was more variable than that of the first molars. CBCT can enhance detection and mapping of the mesiobuccal root-canal system with the potential to improve the quality of root canal treatment.

Endodontic treatment of a geminated maxillary second molar using an endoscope as magnification device

AIM

To describe endodontic treatment for a rare case of gemination.

SUMMARY

A case of complex endodontic treatment in a geminated tooth is presented. With the assistance of microinstruments and magnification devices, a geminated maxillary second molar was successfully treated. In such a case, ultrasonic tips and the use of an endoscope were essential to detect the peculiar anatomy of the tooth involved.

KEY LEARNING POINTS

Knowledge of anomalies concerning fused teeth is essential. Using an endoscope as a magnification device is useful during the inspection of pulp chambers. Ultrasonic tips are safe and useful to detect canal orifices.

Maxillary second molar with 5 roots and 5 canals evaluated using cone beam computerized tomography: a case report

This case report presents the endodontic management of maxillary right second molar exhibiting 5 roots and 5 root canals. The diagnosis was confirmed with the help of cone beam computerized tomography (CBCT). The article also describes the varied morphology associated with maxillary second molar and the use of a high-end diagnostic imaging modality like CBCT in diagnosing and negotiating these anatomic variations.

Maxillary molars with morphologic variations of the palatal root canals: a report of four cases

INTRODUCTION

The purpose of this article was to show the importance of the knowledge of the anatomy of root canals. Unusual root and root canal morphologies associated with both buccal roots of upper molars have been recorded in several studies in the literature. However, scientific information focusing on variations of the palatal root is rare.

METHODS

In this report, four cases are presented involving the root canal treatment of maxillary first and second molars with unusual morphologic configurations of the palatal root canals.

RESULTS

During root canal treatment, type IV and V configurations as defined by Vertucci of the palatal canals of two first and two second maxillary molars were identified. After mechanical instrumentation, the canals were obturated. Radiologic and clinical re-evaluation showed no signs of inflammation.

CONCLUSIONS

This report describes and discusses the possibility of different root and canal variations of the maxillary molars from a clinical point of view. Anatomic variations can occur in any tooth, and palatal roots of maxillary first and second molars are no exception. Therefore, careful examination of radiographs and internal anatomy of teeth is essential.