Incidence Of Middle Mesial Canals Research Articles

Incidence of Middle Mesial Canals in Mandibular Molars during Root Canal Treatment and Nonsurgical Retreatment

IntroductionLarge-scale clinical studies on the incidence of middle mesial canals (MMCs) in nonsurgical root canal treatment (RCT) and retreatment of mandibular molars are lacking. The primary aim of this observational study was to determine the incidence of MMCs in mandibular first and second molars that received RCT or nonsurgical retreatment (NSRetx). The secondary aim was to determine factors associated with incidence of MMCs. MethodsIncluded were 3018 mandibular molars that received RCT (n = 1624) or NSRetx (n = 1394) by 3 endodontists in a private practice. Demographic and procedural data were collected. Bivariate and multivariable (Poisson regression model) analyses were performed. ResultsIncidence of MMCs was 8.8% (n = 267). Although the bivariate analysis showed that NSRetx was significantly associated with incidence of MMCs, this association did not reach the threshold for statistical significance after controlling for all covariates (P = .07). Multivariable analysis on the entire cohort showed that incidence of MMCs was significantly associated with younger age (risk ratio [RR] = 1.62; 95% confidence interval [CI], 1.28–2.06), male gender (RR = 1.48; 95% CI, 1.18–1.85), preoperative cone-beam computed tomography (CBCT) (RR = 1.48; 95% CI, 1.17–1.89), and first molar (RR = 2.30; 95% CI:1.74–3.05). Subgroup multivariable analyses revealed that incidence of MMCs was associated with male gender only in the RCT group (RR = 2.26; 95% CI, 1.55–3.30) but not in the NSRetx group (RR = 1.11; 95% CI, 0.82, 1.50); and with preoperative CBCT only in the NSRetx group (RR = 1.78; 95% CI, 1.28, 2.50) but not in the RCT group (RR = 1.10; 95% CI, 0.71, 1.69). Associations with younger age and first molar remained unchanged. ConclusionsOverall incidence of MMCs was 8.8%. Incidence of MMCs was significantly higher in younger patients and in mandibular first molars but was not associated with the type of treatment.

Prevalence and morphology of middle mesial canal in mandibular first molars in an Indian sub-population: A cone-beam computed tomographic analysis

Aim: The aim of this study was to check for the prevalence and morphology of middle mesial (MM) canals in mandibular first molars in an Indian population divided as per the different zones of the country using cone-beam computed tomography (CBCT) scans. Methods: A total of 452 CBCT scans were selected according to the inclusion and exclusion criteria on December 2021. The scans were obtained from five different zones of the country with 80–100 scans selected from each zone. They were checked in an axial view to see for the presence of a MM canal (MMC) and if present, were confirmed in a coronal view. Results: Of the 452 scans viewed, 39 showed the presence of MMCs (8.6%). Bilateral presence was seen in 8 scans (1.8%). Hence, overall, 47 molars out of 904 examined showed the presence of MMCs. Thus, the tooth prevalence rate for the presence of MMC was 5.2%. Seventy percent of teeth presenting with MMCs showed two apical exits. Males showed more prevalence when compared to the female population (10.25% vs. 6.88%, P < 0.05). Furthermore, with increasing age, there was a consistent decrease in the incidence of MMCs (P < 0.05). Conclusion: Overall, the prevalence of MMCs in an Indian sub-population is 8.6%. Although on a lower range compared to other population, careful exploration is necessary to avoid missing the MMC which might lead to failure of treatment. Age and gender are also found as the important factors that influence the presence of a MMC.

ASSESSMENT OF THE OCCURRENCE OF MIDDLE MESIAL CANAL IN MANDIBULAR MOLARS USING CONE-BEAM COMPUTED TOMOGRAPHY AND DENTAL OPERATING MICROSCOPE: AN IN VITRO STUDY

Introduction: Failures of root canal treatments may be resulted due to missed canals and ignorance of the clinician about the complex anatomy of the root canal system. One such example of anatomic variation is the middle mesial (MM) canal in mandibular molars. Literature on methods for identifying them is limited. Aim: This in vitro study aimed to assess the occurrence of MM canal with cone-beam computed tomography (CBCT) and then under dental operating microscope (DOM) in the mandibular rst and second molars. A total of 40 extract Materials and Method: ed intact human permanent mandibular rst and second molars were selected. These were subjected to CBCT imaging and magnication under DOM for the detection of MM canals. The percentage of incidence in the detection of MMC was compared between these two methods. The incidence of MM canals detected in mandibular molars using CBCT and Results: DOM was 7.50 and 10 % respectively and the comparison between the two methods was statistically not signicant. Since Conclusions: the incidence of MM canals was higher with the use of DOM, it is preferred to use simpler, chairside aids like magnication and ultrasonic troughing. On the other hand, one should be judicious in preoperative CBCT evaluation in nding accessory canals like MM.

Classification and morphology of middle mesial canals of mandibular first molars in a southern Chinese subpopulation: a cone-beam computed tomographic study

BackgroundCone-beam computed tomography (CBCT) was employed to study the morphology and curvature of middle mesial canals (MMCs) of mandibular first molars (MFMs).MethodsCBCT scanning was performed on MFMs of 1100 patients. Patients' images that met the inclusion criteria were divided into group A (< 40 years old) and group B (≥ 40 years old) for further study. The images were used to study the incidence of MMCs at different ages, measure the curvature of MMCs in the mesiodistal and buccolingual directions using the Schneider method, and observe the anatomical morphology of the mesial root canal system. All statistical analyses were performed by using SPSS 21.0 software. Quantitative data were presented as mean ± standard deviation. Student’s t-test was used to calculate the statistical significance. P < 0.05 was considered statistically significant.ResultsIn 875 patients, 1750 MFM images met the inclusion criteria. Among these cases, 158 MFMs contained an MMC, yielding an incidence rate of 9.03%. The incidence rate of MMCs was 11.22% in group A and 6.61% in group B, and this difference was statistically significant (P < 0.05). The curvature in the mesiodistal direction was 29.39 ± 8.53° in group A and 26.06 ± 8.50° in group B, and this difference was also significant (P < 0.05). The curved regions in groups A and B were often located in the middle 1/3 of canal. No significant difference in the distance between MMC orifices and mesiobuccal canal orifices or mesiolingual canal orifices was noted (P > 0.05). The most common mesial root canal morphological type was type II (3-2) (53.80%).ConclusionThe incidence of MMCs in MFMs declined as age increased. The canal systems of MMCs were varied and complex, mainly exhibiting an obvious mesiodistal curve. CBCT is an outstanding method to help guide root canal therapy.*Yeqing Yang and Buling Wu have contribute equally to this article.

Incidence of Middle Mesial Canals Based on Distance between Mesial Canal Orifices in Mandibular Molars: A Clinical and Cone-beam Computed Tomographic Analysis

IntroductionThis study evaluated the presence of midmesial canals (MMCs) in a random sample of mandibular molars and the relationship of the intracanal distance between mesiobuccal (MB) and mesiolingual (ML) canal orifices. MethodsFifty-one extracted mandibular molars were divided into samples of 3 to 4 teeth, mounted in plaster and boxing wax, and immersed in water before cone-beam computed tomographic (CBCT) imaging. Two endodontic residents completed the access openings. The teeth and the CBCT images were interpreted for the presence of MMCs and the mesial intracanal distance. CBCT software measured the distance between the buccal of the MB canal to the lingual of the ML canal at the pulpal floor to determine the average length between the canals. ResultsSeven distinct MMCs were seen both clinically (incidence of 13.725%) and on the CBCT images. Twenty-seven teeth (52.94%) had ambiguous broad isthmi between the MB and the ML orifices. MMCs were present at the furcation level but merged with the MB or ML canal toward the apex in 6 of 7 teeth (85.71%). The mean distance between the mesial canals in teeth with MMCs was 3.643 mm, and it was 3.818 mm for teeth without MMCs. According to independent sample t testing, the P value was >.05. ConclusionsThe incidence of MMCs in mandibular molars appears consistent with the literature. However, there does not appear to be a statistically significant difference in the mesial intracanal distance in teeth with and without MMCs. Visualization of MMCs on CBCTs may be subjective. There does not appear to be a correlation between the presence of MMCs and an increased or decreased mesial intracanal distance.

CBCT detection of the incidence of middle mesial canal and isthmus in the mandibular first molar

CBCT detection of the incidence of middle mesial canal and isthmus in the mandibular first molar

Cone-beam computed tomography for determination of mesial root canal curvatures of human mandibular first molars

To investigate mesial root canal curvatures of human mandibular first molars using cone-beam computed tomography (CBCT). CBCT was performed for scanning the mandibular first molars of 1600 Chinese subjects, among whom the subjects identified to have middle mesial canals were divided into 5 age groups, namely group A (18-29 years), group B (30-39 years), group C (40-49 years), group D (50-59 years), and group E (60-80 years) for further analysis. All the CBCT images were reconstructed using Planmeca Romexis CBCT image reconstruction system, and the curvature of the mesial root was measured using the Schneider method. A total of 2856 CBCT images were obtained from the 1600 subjects, among whom 168 (5.88%) were found to have middle mesial canals in the mandibular first molars. The prevalence of middle mesial canals was 37.50% in group A, 17.80% in group B, 14.88% in group C, 19.64% in group D, and 10.12% in group E. The moderate of the curvature in the mesiodistal direction was significantly higher in group A than in the other groups (P < 0.05); the curvature in mesiodistal direction differed significantly among the 5 groups (P < 0.05), and was the greatest in group A followed by group C and group D, and was the smallest in group E. The curvature in the buccolingual direction was similar among the 5 groups. The incidence of mesiodistal and buccolingual curvature of the middle mesial canals was significantly higher in the middle 1/3 of the root canal than in the upper 1/3 and apical 1/3 of the root canal. The incidence of middle mesial canals in the mesial root of the mandibular first molars decreases with age. The middle mesial canal system of the mandibular first molar is complex and variable, and most of the first molars have obvious curvature in the mesiodistal and buccolingual directions. CBCT can provide reference for clinical treatment to reduce the treatment failure rate.

PREVALENCE OF MIDDLE MESIAL CANALS IN THE MESIAL ROOT OF FIRST PERMANENT MANDIBULAR MOLARS IN EGYPTIAN POPULATION: AN INVIVO COHORT RETROSPECTIVE CONE-BEAM COMPUTED TOMOGRAPHIC STUDY

Objective: The aim of the study was to detect the prevalence of middle mesial canals in the mesial root of first mandibular molars in Egyptian population by retrospective analysis of a large number of cone-beam computed tomography (CBCT) scans. Materials and Methods: A total of 1090 CBCT scans of first permanent mandibular molars were obtained from patients who visited the Faculty of Dentistry, Cairo University, Egypt, for various purposes. CBCT scans were searched and only 800 subjects (374 males and 426 females) fulfilled the inclusion criteria. Results: Middle mesial canal was present in 25.6% (205 of 800) of the subjects. The incidence of middle mesial canal bilaterally was 5.9% and unilaterally was 19.8%. There was no statistically significant difference between males and females (P=0.079). Regarding the distribution of canal (Bilateral and unilateral); there was also no statistically significant difference between males and females ( P =0.056). Conclusion: Among mandibular first molars, there is a high prevalence of a middle mesial canal in the Egyptian population. Detection of its presence is essential to achieve successful endodontic treatment.

Frequency of middle mesial canals in mandibular first molars in North Indian population - An in vivo study

Objectives: The primary aim of the study was to determine the frequency of middle mesial (MM) canals in mandibular first molars in North Indian population. The secondary aim was to analyze whether an association exists between the detection rate of MM canals and age, gender, and number of distal canals. Materials and Methods: All mature mandibular first molars endodontically treated between March 2013 and March 2015 were included in the study. After instrumenting the main canals, the clinician inspected the mesial developmental groove under dental operating microscope (DOM) using ultrasonic tips and endodontic explorer to detect accessory mesial canals. The canal, if found, was negotiated, cleaned, shaped, and recorded. Results were analyzed using Chi-square test. Results: A total of 258 first molars from 243 patients were treated during the specified period, of which 28.3% had negotiable MM canals. The frequency of MM canals was 36.6% in patients 11-30 years old, 22.6% in patients 31-50 years old, and 18.4% in patients >50 years. Statistical analysis revealed a significant relationship of different age groups with the incidence of MM canals (P < 0.05). A significant relationship was also found between the detection rate of two canals in distal root and the presence of MM canals (P < 0.05) with gender having no influence. Conclusion: The presence of MM canals is quite high in North Indian population. Younger patients had a higher incidence of MM canals. Mandibular first molars with two separate distal canals showed a tendency to have MM canals.

Middle mesial canals in mandibular first molars: A micro-CT study in different populations

ObjectiveTo describe the morphological aspects of middle mesial canals (MMC) in mandibular first molars using micro-CT. DesignMandibular first molars collected from the Brazilian (n=136) and Turkish (n=122) populations were scanned (voxel size: 9.9μm) and mesial roots with MMC (n=48) evaluated regarding several morphological aspects. The incidence of MMC in each population was statistically compared using Chi-square test (α=0.05). ResultsOverall, the incidence of MMC was 18.6% (48 out of 258 molars) and was significantly higher in the Brazilian (n=30; 22.1%) than in the Turkish (n=18; 14.8%) population (p<0.05). In both populations, confluent configuration of the MMC was the most frequent anatomy. Most of the specimens with MMC had 3 independent orifices (n=26; 54.2%) and 3 apical foramina (n=21; 43.8%). The mean minor diameter of the MMC orifice (0.16mm) was 3 times less than the other orifices (∼0.50mm). In mesial roots with independent configuration (n=3; 6.3%), the mean volumes (mm3) of the MMC, mesiobuccal (MBC) and mesiolingual (MLC) canals were 0.20±0.10, 0.75±0.28, and 0.88±0.19, respectively. In the specimens with canal confluence (n=26; 54.2%), MMC merged to the MBC (n=8; 16.7%), MLC (n=4; 8.3%), or to both MBC and MLC (n=14; 29.2%). Double mesial canal was observed in only 1 specimen. MMC with an independent foramen was observed mostly in Brazilian specimens. ConclusionsIncidence of MMC was higher in the Brazilian molars. Confluent configuration was the most prevalent anatomic variation, while independent and fin configurations, as well as, double MMC, were found only in a few specimens.

Middle Mesial Canals in Mandibular Molars: Incidence and Related Factors

IntroductionAlthough the internal anatomy of mandibular molars has been extensively studied, information about middle mesial (MM) canals is limited. The primary aim of this retrospective study was to evaluate the incidence of MM canals in mandibular first and second molars. The secondary aim was to correlate the incidence of MM canals with variables of molar type, sex, age, ethnicity, and presence of a second distal canal. MethodsAll mature permanent first and second mandibular molars treated from August 2012 to May 2014 were included in the analysis. After completion of root canal instrumentation in all main canals, the clinician inspected the isthmus area of the mesial root using the dental operating microscope. If there was a catch point in this area with a file or explorer, the operator spent more time attempting to negotiate an MM canal. ResultsSeventy-five mandibular first and second molars were treated during the specified period. Fifteen (20%) teeth had negotiable MM canals. The incidence of MM canals was 32.1% in patients ≤20 years old, 23.8% in patients 21–40 years old, and 3.8% in patients >40 years. Analysis of data revealed a significant difference in the distribution of MM canals among different age groups (P < .05). The differences in the distribution of MM canals based on sex, ethnicity, molar type, and presence of a second distal canal were not significant. ConclusionsThe incidence of negotiable MM canals overall and their frequency of identification in younger patients were higher than in previous reports.