C-shaped maxillary permanent first molar: a case report and literature review

Atypical Root Canal System Anatomy in a Permanent Upper First Molar: A Case Report

Root canal system variations can occur in each tooth group and significantly influence the outcome of the endodontic treatment. Upper first molars often present with some variations, mostly due to the presence of a second mesio-buccal root canal. Other types of atypical root canal system anatomy in upper first molars have also been reported but with a significantly smaller frequency. The aim of this article is to describe a clinical case of a C-shaped root canal configuration in a maxillary first molar - the diagnosis, preparation, irrigation, and final definitive obturation of the root canal system.

Nonsurgical endodontic retreatment of C-shaped maxillary molars: case reports and review of literature

The root canal systems of maxillary first molar (MFM) and maxillary second molar (MSM) variations represent a clinical challenge for endodontists, especially the prevalence of fused C-shaped roots. Having a thorough knowledge of root canal configuration is an extremely important point for a successful root canal treatment to avoid missing extra canals. The aim of this article was to present 2 cases of maxillary molar with an unusual C-shaped configuration diagnosed during root canal retreatment/treatment and conduct a literature review of the MFM and MSM anatomy. Case 1 reports that three separate palatal root canals fused into a C-shaped configuration in the MFM, which with an enamel pearl in the furcation, was classified as Type D and first reported in MFM. Case 2 reflects the fusion of all three buccal canals of the MSM into a C-shaped configuration that finally formed an apical foramen with a supernumerary tooth, and the configuration was Type B. Evaluation at an 18-month and a 9-month recall revealed that two patients were symptom-free after the conduct of a non-surgical retreatment/treatment, and the X-ray revealed normal periapical tissue. In addition, the thickness of the Schneiderian membrane due to odontogenic maxillary sinusitis returns to normal after an effective retreatment in case 1. These reports serve to remind endodontists of the importance and complexity of anatomical variations, which should always be considered when formulating an effective root canal treatment plan. The combined use of cone-beam computerized tomography (CBCT) and a dental operating microscope (DOM) will be profitable to locate and identify extra canals when a periapical radiograph shows signs of an unusual canal morphology.

Endodontic management of a maxillary first molar with three roots and six root canals

Variations in the root canal anatomy of a maxillary first molar are often challenging to diagnose and treat; thus, clinicians must have a thorough knowledge of the same. This case report highlights the successful nonsurgical endodontic management of a maxillary first molar with an unusual morphology of three roots and six root canals. A total of six root canals (mesiobuccal [MB] 1, MB2, MB3, distobuccal [DB] 1, DB2, and palatal) were detected after initiating root canal therapy and access cavity preparation. Conventional root canal treatment was completed, and postoperative cone-beam computed tomography scanning was done to verify the total number of canals and ensure the adequacy of root canal fillings. Managing such cases with rare variations in the root canal systems could be arduous and thus, clinicians should be well-versed in the methods to identify and manage such complexities to facilitate the successful outcomes of endodontic treatment.

The Endodontic Complexity Assessment Tool (E-CAT): A digital form for assessing root canal treatment case difficulty

AIMS

To develop an evidence-based, valid and reliable assessment tool that educational establishments and dental practitioners may use to assess the complexity of root canal treatment (RCT) utilizing digital advancements. The study also aimed to provide a more objective definition of the term 'uncomplicated' root canal treatment as described by the Association for Dental Education in Europe (ADEE) and the European Society of Endodontology (ESE) undergraduate curriculum guidelines for Endodontology.

METHODOLOGY

The development process involved a narrative review of the literature to identify the complexity factors associated with root canal treatment on permanent teeth; an iterative development and analysis process to assess the weighting of these factors; and the programming of digital software to enhance the efficiency and user interface of the assessment form. Validation of the tool was sought with a panel of 35 specialist endodontists to assess clinical scenarios and assess the consensus inter-examiner agreement with the outcomes provided by the E-CAT. The inter-user and intra-user reliability studies were conducted with 15 dentists to evaluate the same clinical cases and by repeating the experiment 9 months later. The ease of use of the form was also assessed.

RESULTS

The E-CAT was successfully developed with a total of 19 complexity criteria and hosted on a secure server under the domain of www.e-cat.uk. The tool provides a smart interactive filtering mechanism and automatic background calculation of the risk scores. Three levels of complexity were defined: class I (uncomplicated), class II (moderately complicated) and class III (highly complicated). The consensus of the panel of endodontists had excellent agreement with the outcome of the E-CAT. The inter-user and intra-user reliability was found to be 0.80 and 0.90, respectively. The average time to assess a case was 1:36 min.

CONCLUSION

The E-CAT gave promising results providing an efficient and reliable platform to assess the complexity of cases undergoing root canal treatments. The study design allowed the formulation of a more objective definition to describe 'uncomplicated' root canal treatment as referred to by the ESE and ADEE guidelines. This study is advantageous for educational, public health and referral pathways.

Analysis of Root Canal Curvature and Root Canal Morphology of Maxillary Posterior Teeth in Guizhou, China

Background

We investigated the root canal curvature and morphology of maxillary posterior teeth in Guizhou, China, to provide references for clinical practice.

Material/Methods

We collected 274 maxillary posterior teeth in Guizhou Province, China. The root canal curvature was observed by X-ray film measurement. Two hundred teeth were selected to make transparent tooth models, and root canal configuration was recorded according to Vertucci classification criteria. The position of the MB2 root canal orifice and the mesiobuccal root canal configuration were observed by micro-computed tomographic (micro-CT) scanning. The t test and the chi-square test were used for statistical analysis.

Results

The root canals of the maxillary posterior teeth showed more significant curvature in the mesiodistal direction than in the buccolingual direction (P<0.05). The MB2 root canal of maxillary molars showed severe bending in the mesiodistal direction: 25.16±6.6 degrees and 28.05±8.65 degrees in first and second molars, respectively. The detection rate of MB2 was 48% in maxillary first molars and 32% in maxillary second molars. The results of micro-CT showed that the vertical distances between the MB2 and MB-P line were 0.64±0.34 mm and 0.57±0.28 mm in first and second molars, respectively.

Conclusions

The root canal morphology and curvature of maxillary posterior teeth varied greatly in the Guizhou population, which increases the difficulty of treatment. It is necessary for clinicians to gain understanding of the root canal and to improve the success rate of root canal therapy.

Endodontic management of the maxillary first molars with two root canals: A case report and review of the literature

BACKGROUND

The complex anatomy of the maxillary first molars has always been a major challenge for complete root canal treatment in endodontic therapy. Here, we present two cases of maxillary first molars, each with only two root canals, which have been rarely reported. We also perform a literature review of maxillary first molar anatomy.

CASE SUMMARY

The two patients were referred to the hospital after 1) finding a cavity in their tooth with a color change and, 2) a toothache during mastication, respectively. Both of these cases were diagnosed as apical periodontitis by X-ray imaging and cone beam computed tomography (CBCT). Non-surgical endodontic therapy was performed with the assistance of a dental operating microscope (DOM). CBCT showed rare but accurate images of both patients, each with two root canals and two roots in their maxillary first molars. Both roots were located in the buccal in the palatal direction, and each root had only one clear root canal. In addition, each maxillary first molar in both patients was symmetrical to that on the opposing side with only two separate root canals. Non-surgical endodontic therapy was performed with the assistance of a DOM. Finally, the teeth were restored using composite resin and the patients were satisfied with the results.

CONCLUSION

Making full use of CBCT and DOM would contribute to helping dentists make correct diagnoses and successfully treat teeth with rare root canal morphologies.

Analysis of Cause of Endodontic Failure of C-Shaped Root Canals

The purpose of this study was to analyze various characteristics and classification of C-shaped root canals and evaluate the causes of endodontic failure of C-shaped root canals by examining the resected root surface with an endodontic microscope and a scanning electron microscope (SEM). Forty-two teeth with C-shaped root canals were included in this study and had undergone intentional replantation surgery. Before surgery, periapical radiography and cone-beam computed tomography were taken. The root canal configuration was analyzed and classified according to Melton's classification at coronal and apical level. After injection of 1 : 100,000 epinephrine with 2% lidocaine, the tooth was carefully extracted. After the root-end resection, the resected root surface was examined using an operating microscope and SEM. Mandibular second molars were most frequently involved teeth (90.4%). The most frequently observed root canal configurations were C1 at the coronal level (45.2%) and C3 at the apical 3 mm level (45.2%). The most common cause of failure for a C-shaped root canal treatment was a leaky canal (45.2%), followed by an isthmus (23.8%), missing canal, overfilling, and iatrogenic problems. In conclusion, C-shaped root canals were most frequently found in mandibular second molars. The most common cause of failure was a leaky canal and isthmus.

Prevalence and Characteristics of the Maxillary C-shaped Molar

INTRODUCTION

The anatomy of the maxillary C-shaped molar has been the subject of several case reports although no true prevalence research has ever been conducted. The aim of this observational study was to evaluate and characterize the incidence of these morphologies using cone-beam computed tomographic (CBCT) technology.

METHODS

Patients having presurgical CBCT examination were selected. CBCT analysis was performed at 5 different axial levels, and the teeth were classified as maxillary molar C shapes according to the inclusion criteria for the present investigation. The prevalence of C-shaped anatomy was calculated. The z test for proportions in independent groups was used to analyze the differences between proportions. Intrarater reliability was also tested.

RESULTS

A total of 2227 teeth (928 upper first molars and 1299 upper second molars) from 895 patients were included in this research. Five different types of C-shaped molars were found, which included fusion between mesiobuccal and palatal roots (type A), mesiobuccal and distobuccal roots (type B), distobuccal and palatal roots (type C), 2 possible palatal roots (type D), and mesiobuccal and palatal roots connecting with an independent distobuccal root canal at apical or between distobuccal and palatal roots connecting with an independent mesiobuccal root canal at apical (type E). The global prevalence was 1.1% for first molars and 3.8% for second molars. Differences were observed between sex, teeth, and some types of C shapes at P < .05.

CONCLUSIONS

Maxillary C-shaped molars have low prevalence but high anatomic complexity. An understanding of their anatomic configuration and variations is important in ensuring that they are treated properly. Distinct differences exist between C-shaped configurations of upper and lower molars.

Aetiology, incidence and morphology of the C-shaped root canal system and its impact on clinical endodontics

The C-shaped root canal constitutes an unusual root morphology that can be found primarily in mandibular second permanent molars. Due to the complexity of their structure, C-shaped root canal systems may complicate endodontic interventions. A thorough understanding of root canal morphology is therefore imperative for proper diagnosis and successful treatment. This review aims to summarize current knowledge regarding C-shaped roots and root canals, from basic morphology to advanced endodontic procedures. To this end, a systematic search was conducted using the MEDLINE, BIOSIS, Cochrane Library, EMBASE, Google Scholar, Web of Science, PLoS and BioMed Central databases, and many rarely cited articles were included. Furthermore, four interactive 3D models of extracted teeth are introduced that will allow for a better understanding of the complex C-shaped root canal morphology. In addition, the present publication includes an embedded best-practice video showing an exemplary root canal procedure on a tooth with a pronounced C-shaped root canal. The survey of this unusual structure concludes with a number of suggestions concerning future research efforts.

Root canal treatment of a two-rooted C-shaped maxillary first molar: a case report

The most difficult maxillary teeth for endodontic treatment are the maxillary first molars (MFM) due to their complex root canal anatomy. The presence of two roots and C-shaped canals in MFMs has been reported in rare cases. The present case reports root canal treatment of MFM with two roots, where the palatal and buccal roots were joined together in a C-shaped configuration.