C-Shaped Canal Configurations in Mandibular and Maxillary Second Molars: A CBCT Analysis in a Malaysian Population.

C-shaped root canal configuration is an unusual root canal morphology and one of the most often anatomical variations in root canal systems of second mandibular molars. The purpose of this study was to assess the prevalence, symmetry and configuration of C-shaped canals in first and second mandibular molars in an Israeli population using cone beam computed tomography (CBCT). One thousand twenty Israel patients' CBCT scans were screened and evaluated. First and second mandibular molars with C-shaped canals were identified. Prevalence configuration along the root and symmetry were analyzed, and new radicular groove classification was proposed. Total of 1465 mandibular second molars and 1229 mandibular first molars were evaluated. The overall prevalence of C-shaped canals in first and second mandibular molars was 0.16 and 4.6%, respectively. No significant difference was found by gender or side of occurrence. The unilateral prevalence of C-shaped canals in mandibular second molars was 55%. C-shaped canal configuration changed along the root in 63% of the cases. The prevalence of C-shaped canals in first and second mandibular molars in the Israeli population is low in comparison to other subpopulations. Clinicians should be aware of the possible asymmetry, different configuration along the root, and the location of danger zone of this anatomic variation during clinical work. CBCT is an efficient three dimensional radiographic examination for evaluation of C-shape root canal configuration. CBCT may help the clinicians during clinical work for considering appropriate cleaning, shaping, and obturation technique according to the characteristic of C-shape root canal configuration.

Analysis of C-shaped canal configuration of mandibular molars in turkish population using cone-beam computed tomography and 3-dimensional modeling.

Mandibular second molars frequently show variation in root canal configurations. The patients with C-shaped canals are quite challenging in dental practice. C-shaped canals have a poor prognosis in terms of debridement, obturation, and restoration. The aim of this study was to investigate the root canal configuration of mandibular second molar teeth and to determine the frequency of C-shaped canals in mandibular second molars. We designed a retrospective study using cone beam computed tomography (CBCT) images and 256 CBCT images were retrieved from the archived records of Necmettin Erbakan University Faculty of Dentistry, Konya, Turkey. The root canal configurations were evaluated according to Vertucci's classification and C-shaped canal configurations were identified using the method of Fan et al. The frequency in percentages was calculated for C-shaped canals in CBCT scans. Of the 444 mandibular second molars, the most frequent canal morphology in the mesial roots was Vertucci type IV (40.3%), followed by type II (27.5%). The distal roots were predominantly type I (92.9%), followed by types III (3.5%) and II (2.5%). Forty-seven (10.6%) teeth had C-shaped canals. Clinicians should be concerned about the different types of canal configurations. Knowledge of these anatomical variations will facilitate the endodontic practice.

Introduction: Root canal anatomy can vary significantly across different ethnic groups, impacting treatment approaches. The presence of a thin lingual wall and a narrow isthmus in C-shaped canals poses a risk of strip perforation, making it challenging for clinicians to fully understand and manage their complex anatomy. A thorough understanding of the configuration of C-shaped canals, including morphologic variations and lingual wall thickness dimensions, is essential for preventing instrumentation errors and ensuring the success of root canal treatment. Aim: To evaluate the prevalence, morphology, and lingual wall thickness of C-shaped root canals in mandibular second and third molars among an Eastern Indian population using Cone Beam Computed Tomography (CBCT). Materials and Methods: This retrospective observational study was conducted in the Department of Conservative Dentistry and Endodontics, Dr. R. Ahmed Dental College and Hospital, Kolkata, West Bengal, India from February 2024 to July 2024. Out of the CBCT scans obtained from 426 patients, a total of 1,416 teeth were analysed, including mandibular second and third molars. The primary inclusion criteria were CBCT scans of fully erupted mandibular second and third molars. The methodology involved evaluating CBCT scans at three levels: coronal, middle, and apical. Additionally, the lingual wall thickness was measured at three zones (coronal, middle, and apical) for each C-shaped canal identified. Demographic parameters, including age and gender, were recorded for each patient to identify any potential associations with canal morphology and lingual wall thickness. For statistical analysis, the Chi-square test was used to analyse categorical variables, and the Kruskal-Wallis test was employed for continuous variables. The level of significance was set at p-value <0.05. Results: A total of 426 CBCT scans were screened, and 1,416 teeth (852 mandibular second molars and 564 mandibular third molars) in 237 males (55.63%) and 189 females (44.3%) were assessed for the presence of a C-shaped canals. The average age of participants was 29.3±8.78 years, with younger individuals having a higher incidence rate (p-value=0.0033). The incidence of C-shaped canals was 6.35% (n=90). Females had a higher proportion of C-shaped canals (71.1%) compared to males (26/90, 28.9%) (p-value <0.0001). Bilateral C-shaped canals were found in 36/54 cases (66.66%), with 29/44 (65.91%) and 7/10 (70%) significantly more prevalent than unilateral cases, which had 15/44 (34.09%) and 3/10 (30%) mandibular second and third molars, respectively (p-value=0.014). C-shaped canals were strongly linked to fused roots in 79 (87.8%) teeth (p-value <0.001). Type C1 was the most prevalent design, with 30 teeth (33.3%) at the coronal level and 36 teeth (40%) at the middle level, while Type C4 dominated the apical level with 43 teeth (47.8%) (p-value <0.001). Type C2 had thinner mesial lingual walls (p-value=0.02). Conclusion: The study identified a higher prevalence of C-shaped canals in mandibular second molars compared to third molars, with a significantly greater occurrence in females than in males. Type C1 configurations were predominant at the coronal and middle levels, while Type C4 was most frequent at the apical level. Lingual wall thickness was thinnest in Type C2 configurations at the mesial zone. These findings highlight the need for clinicians to account for the complex anatomy of C-shaped canals during root canal therapy.

Aim:The aim of this study was to evaluate the prevalence and anatomical configuration of the C-shaped canal in permanent maxillary and mandibular second molars in the Greater Noida population by compiling the results of data that used cone-beam computed tomography (CBCT) analysis.Subjects and Methods:CBCT images were taken from the archive in the department of oral medicine and radiology taken for diagnostic purposes referred by other departments in the dental college. Five hundred CBCT records of patients, between the age group of 15–40 years, containing maxillary second molars and mandibular second molars were selected and reviewed.Statistical Analysis:Statistical analysis was done using the Chi-square test to find out the most common configuration of the C-shaped canal between maxillary and mandibular second molars.Results:Hundred and ten out of 500 patients had C-shaped canals (22%). Among them, 58 teeth (52.7%) were continuous C-shaped canals, 41 teeth (37.3%) were semicolon-shaped canals and 11 teeth (10%) had separated canals. (Chi-square test value = 8.26, P = 0.024). Statistically significant difference was found in configuration types. Among the jaw type, 62 maxillary second molar presented with C-shaped canal (25.1%) and 48 mandibular second molar presented with C-shaped canal (18.9%) (Chi-square test value = 3.87, P = 0.276). However, the difference was statistically insignificant in relation to the jaw type.Conclusions:Within the limitation of the study, we can conclude that the overall prevalence of C-shaped canals was 22% and the most common C-shaped canal configuration type was continuous (52.7%). However, no statistically significant difference was found in relation to jaw type.

Introduction:To evaluate the prevalence of C-shaped root canals in mandibular molars using cone beam computed tomography (CBCT) in a subpopulation of Central India.Materials and Methods:CBCT scans of patients from diagnostic imaging center were selected in accordance with the criteria given by Fan et al. (2004) for C-shaped canals. A total of 238 CBCT scans fulfilled the inclusion criteria and thereby divided into two groups: Group 1: Images showing C-shaped canal configuration in mandibular second molars. Group 2: Images showing C-shaped canal configuration in mandibular third molars. The frequency and distribution of canals and their configuration along with the position of lingual/buccal grooves in the images were evaluated, and the data was analyzed.Results:CBCT evaluation showed that 9.7% of second molars and 8% of third molars had C-shaped canals. A prominent buccal groove was seen in these teeth. The data showed a significant difference (P = 0.038) for the presence of such anatomy on the right side for mandibular third molars.Conclusion:The study showed a significant prevalence of C-shaped canal configuration in the subpopulation studied.

Cone Beam Computed Tomography (CBCT) allows three-dimensional evaluation of external root morphology and internal canal configuration of teeth thus allowing accurate diagnosis of rare complexities in the root canal system. This case study presented root canal re-treatment of a maxillary first molar #16 of a 29 years old female patient, wherein, thorough radiographic examination revealed single root morphology in all the teeth. CBCT analysis confirmed the root form and root canal configuration. Endodontic retreatment of the #16 was performed. The maxillary first molars had single fused roots with C-shaped canal configuration while maxillary second and third molars had O-shaped canals with single fused roots bilaterally. The mandibular first molars had two completely fused roots hence with C-shape canal configuration. While the mandibular second and third molars also had C-shaped canal configuration with single fused roots. The canal configuration of maxillary and mandibular molars was classified according to Martin’s and Fan’s classification respectively. This unique finding of single root with C-shaped canal configuration in all the posterior teeth of a single patient has not been reported in literature.

BackgroundA knowledge regarding anatomical variants is important to achieve success in endodontic treatment. Root canal treatment of mandibular first premolars (PM1 s) is challenging due to the existence of numerous variations in canal configurations, including a C-shaped variant. We aim to determine the frequency and morphologic characteristics of non-single canals of mandibular first (PM1 s) and second (PM2 s) premolars in a Korean population using cone beam computed tomography (CBCT) and to evaluate correlations between non-single canals of PM1 s and other anatomical variants, such as distolingual roots (DLRs) in mandibular first molars (M1 s) and C-shaped canals in mandibular second molars (M2 s).MethodsA total of 971 PM1 s and 997 PM2 s from 500 patients were examined in vivo by CBCT. Root canal configurations and C-shaped canals were determined in accordance with the Vertucci classification and Fan classification, respectively. The correlation between non-single canals in PM1 s and DLRs in M1 s was evaluated using logistic regression analysis.ResultsPM2 s typically had one root (99.89%) with one canal (98.4%). Among PM1 s with non-single canals (21.2%), Vertucci type V (10.9%) and C-shaped (3.7%) canals were prevalent. Among C-shaped PM1 canals, the majority were Vertucci type V (77.8%); a C-shaped configuration (C2) was predominant mostly at the middle and/or apical third of the root. After adjusting for other variables (i.e., sex, age, and side), C-shaped canals in PM1 s was significantly correlated with the presence of DLRs in M1 s (odds ratio = 2.616; 95% confidence interval, 1.257–5.443; p = 0.010).ConclusionsThe presence of C-shaped PM1 canals was positively related to the presence of DLRs in M1 s. Although C-shaped canals in PM1 s are difficult to distinguish, this finding could aid clinicians in predicting C-shaped canal configurations in PM1 s of patients who exhibit DLRs in M1 s.

This study aimed to assess the prevalence and morphology of lower second molars with C-shaped configuration among patients at the University of Barcelona Dental Hospital using cone beam computed tomography (CBCT). CBCT images of 408 patients, comprising 792 lower second molars, were examined to identify C-shaped canals and evaluate their anatomical characteristics. Inclusion criteria required patients to have both lower second molars present. The configuration of C-shaped canals was categorised at three axial root levels. The variables of symmetry, position, gender and age were analysed. Out of the 792 lower second molars analysed, a total of 65 molars with C-shaped canals were identified in 42 patients, representing a prevalence of 10.2%. The prevalence in females (12.6%) was significantly higher than in males (6.5%). Bilaterality was observed in 54.76% of individuals with C-shaped molars. The C1 configuration was most frequently observed in the coronal third (56%), while the C2 configuration was equally distributed between the coronal and middle thirds (44.1%). The C3 configuration was most prevalent in the middle third (41.4%), and the C4 configuration was predominantly observed in the apical third (96%). Variations in configurations along the root were observed in 70.8% of the molars. The longitudinal groove was predominantly located on the lingual surface of the roots (83.1%). CBCT is a useful tool to analyse the morphology of the root canal system. Key words:C-shape, anatomy, prevalence studies, root canal, Cone beam computed tomography, mandibular second molar.

ObjectivesTo determine the prevalence of C-shaped root canal system configurations and assess the correlation between C-shaped root canal prevalence and root morphology in mandibular second molars among adults in Xinjiang Uyghur population using cone-beam computed tomography (CBCT).Materials and methodsCBCT imaging data from patients treated at the First Affiliated Hospital of Xinjiang Medical University (Affiliated Stomatology Hospital) were retrospectively analyzed. The prevalence of C-shaped root canal configurations in mandibular second molars was determined based on Fan et al.‘s classification. Axial sections of each tooth were evaluated in the coronal, middle, and apical thirds to identify canal configurations and analyze root morphology. The differences in C-shaped canal prevalence between genders and tooth positions were compared. Statistical analysis was performed using the chi-square test (p < 0.05).ResultsA total of 1748 patients were included, with 510 (29.17%) exhibiting C-shaped root canals. Females exhibited a higher prevalence (31.49%) than males (25.15%). C-shaped canals were more frequently observed on the lingual surface (76.8%) than the buccal surface (22.2%). Bilateral symmetry of C-shaped canals was observed in 64.7% of cases. A significant association was found between C-shaped canals and root morphology (p < 0.001). Among patients with C-shaped canals, 66.9% demonstrated symmetrical configurations. The most common configuration was C3 (present in all axial levels), followed by C1 and C2. Mandibular second molars with three roots or type 3/type 4 morphologies exhibited a high probability of C-shaped canals.ConclusionsC-shaped canals were more prevalent in females and lingually positioned in mandibular second molars. Bilateral C-shaped canals were frequently symmetrical and more common than unilateral cases. Mandibular second molars with three-root or type 3/type 4 morphologies may indicate a high likelihood of C-shaped canals. The most common configuration was C3, followed by C1 and C2, all present across all axial levels. Understanding these anatomical variations preoperatively can improve clinical management.

Objectives This study aimed to analyze the root canal morphology of first and second permanent mandibular molars among Makkah population by using cone-beam computed tomography (CBCT). Materials and Methods CBCT images of two hundred eight patients were obtained from the Faculty of Dentistry, Umm Al-Qura University, Makkah, Saudi Arabia. In all images, mandibular first and second molars were evaluated for the number of roots and their morphology, number of root canals, canal configuration in each root according to Vertucci's classification, and the presence of a C-shaped canal. Results Most of the mandibular first molars had two roots (96.5%) and three root canals (77.7%). Type IV canal configuration prevailed (75.6%) in the mesial roots, and type I canal configuration prevailed (71.7%) in the distal roots. For the mandibular second molars, the majority had two roots (96.3%) and three root canals (82.7%). Type IV canal configuration prevailed (48%) in the mesial roots and type I (99.1%) in the distal roots. C-shaped canals were detected in 5.7% of the mandibular first molars and 4% of the mandibular second molars. There was no statistical difference between the mandibular first and second molars (P > 0.05) in the shape of the roots and the presence of the C-shaped canals. Conclusion Most of the mandibular molars in Makkah population presented with two roots and three root canals. The incidence of three-rooted mandibular molars was low, and it was higher in the first molars than second molars. The type IV root canal system prevailed in mesial roots and type I in distal roots.

Aim: This study aims to evaluate the anatomical features and prevalence of C-shaped roots and longitudinal grooves in mandibular first and second permanent teeth using cone-beam computed tomography (CBCT).Material and Methods: CBCT records of first and second mandibular teeth from 839 patients who applied to the Department of Oral and Maxillofacial Radiology between 2011 and 2018 were used. The CBCT examination was performed at five different axial levels and the mandibular molars were classified as types of longitudinal groove and C-shape according to the Fan criteria. Differences between genders, age groups, left and right side and type of tooth were determined.Result: A total of 2903 teeth (1321 first molars and 1582 second molar) from 839 patients were included in the study. C-shaped canals were found in mandibular first molar teeth with a prevalence of 0.15%, while 4.1% in mandibular second molar teeth. Only two mandibular first molars exhibited C-shaped canal. Female patients had a higher prevalence than males. Longitudinal grooves were most commonly found lingual surface. Conclusions: The occurence of C-shaped canals in mandibular first and second molars among Turkish population was generally less than in other populations. CBCT is a valuable tool to evaluate the C-shaped root canal configuration in vivo. Keywords: Cone-beam computed tomography; C-shaped canal; mandibular molar

This retrospective study of roots with C-shaped canals investigated their prevalence, configuration type, and lingual wall thickness, as well as the panoramic radiographic features of roots in permanent mandibular second molars confirmed to have C-shaped canals on cone-beam computed tomography (CBCT) in a Korean population. In total, 1884 CBCT images of mandibular second molars were examined by two endodontists to analyze the presence of C-shaped canals according to age and sex. The bilateral occurrence of C-shaped roots and their morphology on panoramic radiography were assessed and statistically analyzed using the chi-square test. The classification of Fan et al. was applied to categorize the configurations of C-shaped canals. The lingual wall thickness was calculated in the mesial, middle, and distal areas at the orifice and at 5 mm from the apex. The Mann–Whitney U test was used to analyze the mean difference of lingual wall thickness between the apex and orifice level. A P value of 0.05 was considered to indicate statistical significance in the statistical analyses. Of 2508 mandibular second molars, 924 (36.8%) had C-shaped root canals. The prevalence was significantly lower in the over 61 age group (24.08%) than in the 21–30-year age group (40.02%) and was higher in women (42.32%). Most cases were bilateral (85.9%). The C1 type was the most common (35.3%). The prevalence of C1 type canals decreased, while that of C3b type canals increased with age. In 75.2% of teeth having C-shaped root canals on CBCT, fused roots were observed on panoramic views. The difference in the lingual wall thickness at the orifice and 5 mm from the apex was significant in the middle area in all configurations of C-shaped root canals. When performing nonsurgical or surgical endodontic procedures of the mandibular second molars, clinicians should consider age, sex, ethnicity, and anatomical variations.

Introduction: Due to the importance of familiarity with root canal morphology in order to completely clear the canal and achieve treatment success, the aim of this study was to use Cone-Beam Computed Tomography (CBCT) images to evaluate the frequency and anatomy of C-shaped canals in the first and second mandibular molars. Materials and Methods: In this cross-sectional study, CBCT images of 209 patients (435 teeth) were evaluated to determine the presence of C-shaped canals and their anatomical morphologies along the root, based on Fan classification. Bilateral or unilateral occurrence of C-shaped canals and their relationship with gender, age and tooth location were examined and statistically analyzed using the chi-square test and SPSS 17 software. The significance level was P &lt; 0.05. Results: CBCT images from 209 patients, 103 patients (49.3%) were female and 106 (50.7%) were male. Out of 435 teeth (157 mandibular first molars and 278 mandibular second molars) evaluated, 33 specimens (7.5%) including the 2 first molars (1.27%) and 31 second molars (11.15%) had a C-shaped canal system which were from 25 patients (2 first molars in 2 patients and 31 second molars in 23 patients). The prevalence of bilateral C-shaped canals was among the 97 patients with bilateral second molars (6.18%). There was also no significant relationship between teeth position, gender and the prevalence of C-shaped canals. Conclusion: The configuration of C-shaped canals extensively changes along the length of the root and should be considered during preparation and obturation of root canal system.

The diverse morphological configurations in teeth present clinical challenges in root canal treatment, complicating instrumentation and irrigation processes, which can lead to treatment failure. Understanding anatomical variations, such as C-shaped canals and radix entomolaris, enhances clinical skills and improves long-term endodontic treatment success rates. Cone-beam computed tomography (CBCT) offers superior diagnostic capabilities over conventional radiography, enabling the pre-operative detection of root configurations and canal numbers, facilitating personalized endodontic treatments. A total of 2173 teeth of a Mexican population, including 1057 first mandibular molars and 1116 s mandibular molars, were studied using only CBCT to identify C-shaped canals and radix configurations of patients who were treated from 2018 to 2023 at the Department of Radiology at the Faculty of Dentistry, Juarez University of the State of Durango, Mexico. C-shaped canals were identified in 160 teeth, with a prevalence of 0.2% in first mandibular molars and 14.1% in second mandibular molars. The highest frequency was in the left second mandibular molar (3.7) at 14.8%. Gender differences were significant, with higher prevalence in females (27.3%) compared to males (13.3%). The most common C-shaped canal configuration was type C2 (39.3%). Radix entomolaris was found in 52 teeth, with a prevalence of 3.4% in first mandibular molars and 1.4% in second mandibular molars. This research on a Mexican population using cone-beam computed tomography (CBCT) highlights significant findings in the prevalence and types of C-shaped canals and radix entomolaris in mandibular molars for this population. The left second mandibular molar (3.7) showed the highest prevalence at 14.8%, followed closely by the right second mandibular molar (4.7) at 13.5%, with a significant difference (p < 0.001). We found a significant difference in the prevalence of C-shaped canals between genders (p = 0.004, OR 1.78). Additionally, radix entomolaris (p < 0.001) was more frequently identified in first mandibular molars to a significant degree. These insights underscore the importance of CBCT in diagnosing complex root anatomies, which can greatly enhance the success rates of endodontic procedures by allowing for more tailored and precise treatments for this population.