Root anatomy and root canal configuration of human permanent mandibular premolars: a systematic review

Multipopulation evaluation of the internal morphology of mandibular first premolars from different South American countries. A micro-computed tomography study

OBJECTIVE

To evaluate and compare several anatomical parameters of mandibular first premolars from individuals from different Latin American countries using micro-computed tomography.

DESIGN

Five hundred extracted mandibular first premolars from Brazilian, Argentinian, Chilean, Colombian, and Ecuadorian individuals were scanned using micro-computed tomography (n = 100 teeth/country). Root canal configurations were classified according to established parameters. Analyses also included: canal volume and surface area, structure model index, distances from the apical foramen to the root apex or the cementoenamel junction, major/minor apical canal diameters, canal orifice shape, and prevalence of ramifications.

RESULTS

A single root was the most common anatomy in all countries (range, 97%-100%). Vertucci's type-I canal was the most frequent configuration (range, 36%-66%), followed by C-shaped and type-V canals. The oval-shaped canal orifice was the most predominant in all countries (range, 34%-58%), followed by the circular shape (range, 16%-47%). C-shaped canals occurred in all subpopulations (range, 14%-26%), always associated with radicular grooves. Ranges for canal ramifications were as follows: accessory canals, 36%-73%; lateral canals, 4%-12%; and apical delta, 4%-14% of the teeth. Many anatomic parameters differed significantly between countries (P < .05).

CONCLUSIONS

Vertucci's types-I and -V, and C-shaped canals were the most prevalent configurations in the subpopulations investigated. Accessory canals and several complex anatomies were found, with some significantly different frequencies between countries.

CBCT and Micro-CT analysis of the mandibular first premolars with C-shaped canal system in a Chinese population author

OBJECTIVES

The purpose of this study was to survey the prevalence of C-shaped root canal system in mandibular first premolar in Chinese population by reading Cone-beam computed tomography (CBCT) images and to analyze its anatomical characteristics by CBCT and Micro-computed tomography (Micro-CT).

METHODS AND MATERIALS

The prevalence and the morphologic features of C-shaped root canal system were evaluated by observing CBCT images of 760 patients (1520 mandibular first premolars). 66 mandibular first premolars with C-shaped root canal system were scanned by Micro-CT. The morphologic features including radicular groove, C-shaped root canal categories in the cross-sections and in the 3D models, accessory and connecting canals, apical foramina and accessory foramina, were analyzed using image software.

RESULTS

C-shaped root canal system was identified in 16.9% of mandibular first premolars. The minimum mesial wall thickness most commonly occurred at the lingual site (69.7%). Regarding to the cross-sectional classification, the maximum was C2 (41.5%). In the 3D classification, the most common was S (34.8%). Accessory canals were observed in 36.4% of the samples and occurred mostly in the middle and apical regions. 42.4% samples had 1-3 variable connecting canals, and 40.9% samples had only one apical foramen.

CONCLUSIONS

The incidence of C-shaped root canal system in mandibular first premolars was 16.9% in the Chinese population. The anatomy was very complex and variable, mostly distributed in the middle and apical regions of the root canal. The mesial wall of C-shaped canal was extremely thin on the lingual side.

Root Canal Morphology of Premolars in Saudis

AIM

This study aimed to evaluate root number and morphological variations of the root canal system in maxillary and mandibular premolars among the Saudi subpopulation.

METHODOLOGY

A total of 500 cone-beam computed tomography (CBCT) images were assessed, including 2442 maxillary and mandibular premolars. The evaluation encompassed the number of roots and canals and their configuration based on the Vertucci classification. Gender differences were considered, along with the position of premolars and unilateral or bilateral symmetry.

RESULTS

Maxillary first premolars predominantly exhibited two roots (82.6%), followed by one root (16.3%) and three roots (0.97%), with a majority having two root canals (83.6%). Regarding maxillary second premolars, the most common morphology was one root (66.6%), with two root canals (40.5%) observed more frequently than one root canal (38.1%). Mandibular first and second premolars mainly featured one root (84.8% and 96.1%, respectively) with one root canal (70.8% and 90.2%, respectively), whereas two root canals were less prevalent (2.3% and 1.8%, respectively). Three canals and three roots were rarely found in mandibular premolars (0.3%). Regarding maxillary premolars, males exhibited significantly higher type IV and mandibular type I root configurations compared with females. Conversely, regarding mandibular premolars, females showed significant mandibular type V and higher type I root configurations compared with males.

CONCLUSION

CBCT imaging facilitated precise assessment of root morphology and root canal configurations in maxillary and mandibular premolars. The present findings can aid dentists in diagnosing, evaluating case difficulty, and devising effective root canal treatments, particularly in patients from Saudi Arabia.

Evaluation of root and canal morphology of mandibular premolar amongst Saudi subpopulation using the new system of classification: a CBCT study

BACKGROUND

The clinician should have complete knowledge of the normal anatomy of the root as well as complexities in the root canal configuration for a better outcome, as missed or improper handling of the canal system can lead to the failure of an entire endodontic procedure. The present study aims to assess the morphology of roots and canals in permanent mandibular premolars in the Saudi subpopulation with a new classification system.

METHODS

The present study includes 1230 mandibular premolars (645 first premolars and 585-second premolars) from 500 CBCT images of the patients, including retrospective data. iCAT scanner system (Imaging Sciences International, Hatfield, PA, USA) was used to obtain the images; scanning of 8 × 8 cm images was performed at 120 KVp and 5-7 mA with a voxel size of 0.2 mm. The new method of classification presented by Ahmed et al. 2017 was used to record and classify the root canal morphology, followed by recording the differences regarding the age and gender of the patients. Comparison of canal morphology in lower permanent premolars and its association with gender and age of the patients was done by Chi-square test/ Fisher exact test; the significance level was set at 5% (p ≤ 0.05).

RESULTS

The left mandibular 1st and 2nd premolars with one root were 47.31%, with two roots were 2.19%. However, three roots (0.24%) and C-shaped canals (0.24%) were reported only in the left mandibular 2nd premolar. The right mandibular 1st and 2nd premolars with one root were 47.56%, with two roots were 2.03%. The overall percentage of the number of roots and canals in the first and second premolars ¹ PM ¹ (88.38%), ² PM ¹ B ¹ L ¹ (3.5%), ² PM B ¹ L ¹ (0.65%), ¹ PM ^1-2-1 (3.08%), ¹ PM ^1-2 (3.17%), ¹ PM ^1-2-1-2 (0.24%), ³ PMMB ¹ DB ¹ L¹ (0.48%). However, the C-shaped canals (0.40%) were reported in right and left mandibular second premolars. No statistically significant difference was reported between mandibular premolars and gender. A statistically significant difference was reported between mandibular premolars and the age of the study subjects.

CONCLUSION

Type I (¹ TN ¹) was the major root canal configuration in permanent mandibular premolars, which was higher among males. The CBCT imaging provides thorough details about the root canal morphology of lower premolars. These findings could support diagnosis, decision-making, and root canal treatment, for dental professionals.

Detection and Endodontic Treatment of Unusual Anatomic Variations in Second Premolars: A Case Report

Endodontic treatment of second premolars is challenging due to their complex anatomy and the likelihood of anatomical variations. The current report presents successful treatments of mandibular and maxillary second premolars with different anatomies in a single patient. The first case involved a patient referred from a general practitioner who was unable to complete the root canal treatment of her mandibular second premolar with four root canals. The initial radiograph showed an apical radiolucency, periodontal ligament (PDL) widening, and a fast break suggesting the possibility of root canal branching. With the diagnosis of previous treatment and chronic apical periodontitis, the tooth was successfully retreated with the aid of cone-beam computed tomography (CBCT), a dental operating microscope, and ultrasonic tips. The second case was a maxillary second premolar with Vertucci's type VI root canal morphology, which was not responsive to pulpo-periapical tests. Along with a deep carious lesion and a PDL widening on the initial radiograph, a diagnosis of necrosis with chronic apical periodontitis was made. The root canals were located and treated using a combination of radiography with different angulation and CBCT. Both teeth were clinically and radiographically asymptomatic at the 4-month follow-up session. This case report highlights the importance of thorough preoperative evaluation and the use of advanced technology and techniques in achieving successful endodontic treatment outcomes.

Prevalence and correlation of C-shaped root canals of mandibular premolars and molars in Eastern Chinese individuals

The aim of this study was to investigate the prevalence, correlation, and differences of C-shaped root canals (CSRCs) morphology in permanent mandibular premolars and molars in Eastern Chinese individuals using cone-beam computed tomography (CBCT). A total of 8000 mandibular first premolars (MFPs), mandibular second premolars (MSPs), mandibular first molars (MFMs), and mandibular second molars (MSMs) CBCT images from 1000 patients (692 females and 308 males) were collected. The prevalence, correlation, bilateral/unilateral presence, the morphology of CSRCs, level of canal bifurcation, gender differences, and location of radicular grooves (RGs) were evaluated. The prevalence of CSRCs in MFPs, MSPs, MFMs and MSMs were 10.25%, 0.25%, 0.55% and 47.05%, respectively. The prevalence of CSRCs in MFPs of males was higher than that in females, while the prevalence of CSRCs in MSMs of females was higher than that in males (P < 0.05). The bilateral symmetry presence of CSRCs in MSMs was significant but not in MFPs, MSPs, and MFMs. RGs were predominantly found on the mesiolingual (ML) surface of premolars and the lingual surface of molars. There was a high prevalence of CSRCs in MFPs and MSMs in the Eastern Chinese population, but there was no correlation. The prevalence of CSRCs in MFPs and MSMs differ significantly by gender (P < 0.05).

Root Morphology and Canal Configuration of Permanent Canines Among Saudi Population: Systematic Review and Comparison with Worldwide Studies

Aim

The root morphology and canal configuration (RMCC) of mandibular and maxillary canines among Saudi population is systematically reviewed and compared with international studies in this research.

Methods

This study was carried out following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations. The electronic databases of PubMed, Science Direct, Scopus, Wiley Library, Google website search, and Web of Science were searched. Only local and international cross-sectional, comparative, evaluation, and validation studies or case reports published between 2016 and 2022 that directly evaluated canine RMCC and assessed participants using cone beam computed tomography were included.

Results

Forty-three studies that investigated RMCCs (17 local and 26 international) were involved in this review. The original Saudi research recorded that almost 100% of maxillary canines had one root and one canal, whereas 98.4% and 94.1% had one root and one canal in the mandibular arch. Vertucci’s class I had the highest percentages in the maxillary and mandibular arches at 98.3% and 95.8%, respectively, followed by class III with 0.7% and 1.9% for the same arches, respectively. International studies recorded that 100% of maxillary canines had one canal and root; the percentages of the mandibular arch were 92.3 and 98% for single canal and root, respectively; and the highest percentage was obtained by Vertucci’s class I (91.1%), followed by class III (4.7%).

Conclusion

This review reports and confirmed the symmetry of the RMCCs of maxillary and mandibular canines between Saudi studies and other populations. Moreover, Vertucci’s classes I and III were the most frequent RMCCs, and two-rooted canines in both arches were considerably less frequently than single-rooted ones.

The Hidden Anatomy of a Lower Premolar With Two Canals

Variations in the root canal configuration are a great challenge for the endodontist during endodontic procedures. This necessitates the understanding of canal morphology before initiating the treatment. Mandibular second premolars have been always studied to have only a single canal in their root. The present case reported shows an unusual, rare occurrence of an extra canal in the single-rooted second premolar. The patient reported pain associated with #35 which was due to deep distant proximal caries. The second canal was revealed during the intraoperative phase and was successfully treated. The current case adds an important insight to the existing literature related to diverse canal configurations in lower premolars.

Three-Rooted Permanent Mandibular First Molars: A Meta-Analysis of Prevalence

Introduction

Although numerous amounts of high-level evidence were present, they solely emphasized the tooth-level prevalence of three-rooted permanent mandibular first molar. Global patient-level prevalence and bilateral symmetrical distribution of this type of teeth were needed to be tackled across the world. The research question was “What is the global prevalence of three-rooted permanent mandibular first molars?”

Materials and Methods

In vivo epidemiological studies undergone with Cone Beam Computed Tomography (CBCT) were eligible. The proportions of the prevalence of three-rooted permanent mandibular first molars were presented in the forest plots by random effect model. The calculation was performed with MetaXL version 5.3. Subgroup analysis, sensitivity analysis, and publication bias method were also calculated.

Results

Seventy-two studies from 31 countries were selected for both qualitative and quantitative analyses. 26302 patients and 37994 permanent mandibular first molars were included in the analysis. 9% of permanent mandibular first molars all over the world demonstrated 3 roots. These three-rooted teeth were found in 10% of the world population, more than 45% of which revealed bilateral symmetry of that anatomy. Right-side dominance and no sexual dimorphism were seen in the distribution of three-rooted permanent mandibular first molars. Global tooth-level prevalence of Radix Entomolaris and Radix Paramolaris was 12% and 0.1%, respectively.

Conclusion

The prevalence of three-rooted permanent mandibular first molars (PMFMs) was influenced by different geographical locations across the world and also by widespread habitation of the Mongoloid descent. The authors postulate that globalization, together with blending among ethnicities, may have a great impact on the reduction or accentuation of the anatomical significance in some populations.

Adaptation of a Single-Cone in Prepared Teeth with Two Reciprocating Systems

Introduction

This ex vivo study aimed to compare the adaptation of single gutta-percha cone in teeth prepared with the Wave One Gold and Reciproc Blue reciprocating systems through cone-beam computed tomography.

Materials and Methods

A total of 40 recently extracted mono radicular premolars were randomly assigned into two groups (n=20) corresponding to Reciproc Blue and Wave One Gold reciprocating systems and adapted to a single cone system. Each group was evaluated by cone-beam computed tomography at 1 mm, 2 mm and 4 mm from the apical foramen. We evaluated the number of walls adapted by the cone, quality of filling and the number of spaces between the filling and the walls of the root canal. The Mann-Whitney U and T-tests were employed to associate and compare both groups (P<0.05).

Results

At 1 mm in the lingual wall the Wave One Gold system did not adapt by 45% compared to 15% with Reciproc Blue (P<0.05). Likewise, the single-cone filling technique of the Reciproc Blue system showed better sealing quality obtaining an ideal category (75%) compared to Wave One Gold (40%) (P<0.05). The amount of space (mm) found between the cone and the filling walls was greater with Wave One Gold. However, these values were not statistically significant.

Conclusions

Based on this ex vivo study the better adaptation of root canals and ideal filling condition was more frequent with Reciproc Blue than Wave One Gold system, mainly at 1 mm from the radicular apex.

THE PREVALENCE OF A SECOND ROOT CANAL IN MANDIBULAR ANTERIOR TEETH VARIES BY GEOGRAPHIC REGIONS AND DEMOGRAPHIC FACTORS

ARTICLE TITLE AND BIBLIOGRAPHIC INFORMATION

Martins JNR et al. Influence of Demographic Factors on the Prevalence of a Second Root Canal in Mandibular Anterior Teeth - A Systematic Review and Meta-Analysis of Cross-Sectional Studies Using Cone Beam Computed Tomography. Arch Oral Biol. 2020 Aug;116:104,749. doi: 10.1016/j.archoralbio.2020.104749.

SOURCE OF FUNDING

No funding was obtained for this research TYPE OF STUDY/DESIGN: Systematic review with meta-analysis.

Canal configuration and root morphology of mandibular premolars using cone-beam computed tomography in a Korean population

OBJECTIVES

This study aimed to investigate the anatomy of mandibular premolars from two perspectives-the canal configuration and radicular grooves-using cone-beam computed tomography (CBCT) in a large Korean population.

MATERIALS AND METHODS

CBCT images of mandibles acquired from March 2018 to December 2019 for dental treatment were randomly selected. In each image, the root canal of premolars was classified into 8 types according to the canal merging or diverging pattern and the number of apical foramens. The presence and the location of radicular grooves were also assessed. Statistical analysis was performed.

RESULTS

A total of 1463 first and 1448 s premolars from 732 patients (390 males, 342 females, mean age of 36.1 years) were evaluated. A single canal with one foramen predominated in both first (85.7%) and second (99.5%) premolars, while complete or partial multi-canals accounted for 14.3% and 0.5% of first and second premolars, respectively. The prevalence of radicular grooves was significantly higher in first premolars (13.2%) than in second premolars (0.5%) and in males (4.3%, n = 119) than in females (2.5%, n = 73).

CONCLUSIONS

Although most premolars were complete single canals, the first premolars showed a relatively higher number of complex canals compared to the second premolar. In addition, radicular grooves in mandibular premolars were significantly more common in male patients.

CLINICAL RELEVANCE

When planning the endodontic treatment of mandibular premolars, clinicians should be aware of their morphologic complexity, especially in the first premolar of male patients.

Prevalence of complex root canal morphology in the mandibular first and second premolars in Thai population: CBCT analysis

Background

Mandibular premolars demonstrate high variability in root canal morphology, especially mandibular first premolars. The purposes of this study were to determine the prevalence of root canal configurations of mandibular premolars according to Vertucci classification in a Thai population.

Methods

Total of 1159 CBCT images of Thai patients who received radiographic imaging at the Department of Radiology, Faculty of Dentistry, Chulalongkorn University in 2017–2018 was evaluated. The data were reported using descriptive statistics and the relationship between the prevalence of the root canal complexities and sex was analyzed using the chi-squared test.

Results

The most common root canal configuration was Vertucci type I, with a 63.1% and 98% prevalence in the mandibular first and second premolars, respectively. More than 98% of mandibular premolars had a single root. The prevalence of a bifurcation was 28.5% and 1.5% in the mandibular first and second premolars, respectively. The prevalence of a trifurcation was 3.2% in the mandibular first premolar. A C-shaped root canal was observed at 23.7% and 0.7% in the mandibular first and second premolars, respectively. The level of branching was mostly found at the middle 1/3 of the root. Bilateral appearance of the same root canal configuration was identified in 80.3% and 95.9% in the mandibular first and second premolars, respectively. There was no relationship between sex and the prevalence of a bifurcation, trifurcation, or C-shaped root canal.

Conclusion

Mandibular first premolars have more root canal complexities than mandibular second premolars. Horizontal tube shift x-ray technique, CBCT, dental operating microscope, and knowledge of root canal configurations have an important role in root canal identification in mandibular premolar with suspected complex root canal morphology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01822-7.

Cone-beam computed tomography evaluation of C-shaped root and canal morphology of mandibular premolars

BACKGROUND

Mandibular premolars are complicated teeth to endodontically treat due to the anatomical variations that can present. The purpose of this study was to determine the presence of C-shaped configurations in mandibular premolars by cone-beam computed tomography (CBCT).

METHODS

380 mandibular first premolars and 308 mandibular second premolars cone-beam computed tomographic images were obtained from 292 patients (175 female and 117 male). Tooth position, number of roots, root canals, C-shaped root canal system configuration, level of canal bifurcation and radicular grooves were evaluated by two endodontists trained in CBCT evaluation; previously calibrated between them, and a radiologist with endodontic experience. Data were statistically compared by The Chi-square test (α = 0.05) to examine any significant difference between gender and C-shaped root canal system and any significant difference between C-shaped configuration according to Fan criteria and gender.

RESULTS

Overall 100% (n = 688) teeth examined, 19.2% (n = 132) had a C-shaped root canals system. 9.16% (n = 63) in male patients and 10.03% (n = 69) in female patients. The prevalence of C-shaped root canal system in mandibular first premolar was 83.33 and 16.66% in mandibular second premolars. According to Fan classification, the mandibular first premolars showed 3.63% as C1, 9.09% C2, 59.09% C3, 21.81% C4a, 1.8% C4b. Mandibular second premolars showed 13.63% as C1, 18.18% C2, 13.63% C3, 27.27% C4a, 9.09% C4b. Male patients showed 4.54% as C1, 3.78% C2, 22.72% C3, 11.36% C4a, 0.75% C4b, and 4.54% out of classification. Female patients showed 0.75% as C1, 6.81% C2, 30.03% C3, 9.84 C4a, 2.27% C4b, and 2.27% out of classification. The 53.36% canal bifurcation in mandibular first premolars and 50.09% in mandibular second premolars were in the middle third. No statistical differences were found between C-shaped root canal system and gender or C-shaped configuration according to Fan criteria and gender. P was < 0.05.

CONCLUSIONS

Within the limitation of this study, the presence of C-shaped anatomical system is relatively low in mandibular second premolars than in mandibular first premolars.

Interpretation of Root Canal Anatomy of Maxillary and Mandibular Permanent Canines in Saudi Subpopulation: A Cone-Beam Computed Tomography (CBCT) Study

The objective of this investigation was to evaluate the root canal anatomy of permanent canines in a Saudi subpopulation utilizing CBCT. A total of 1328 CBCT images of maxillary (634) and mandibular (694) permanent canines were collected from Saudi patients who visited the College of Dentistry at King Saud University in Riyadh. The images were analyzed for root and canal numbers, canal configuration types, and symmetry between the bilateral canine teeth in each arch. Gender, age, and tooth position were recorded. The Kappa test was used for both inter- and intraexaminer reliabilities. Data were analyzed with the chi-square test at a P value ≤ 0.05. There were no two-rooted teeth in maxillary canines, and 1.89% had two canals. Double roots and double canals in mandibular canines were found in 2.88% and 9.94% of the teeth, respectively. Type I canal configuration was more common in maxillary canines (97.94%) compared to mandibular canines (92.07%). Maxillary canines showed higher bilateral symmetries of root and canal numbers and canal configuration types (100%, 98.1%, and 97.9%, resp.) compared to mandibular canines (97.1%, 90.1%, and 92.1%, respectively). The majority of maxillary and mandibular canines had a single root with a single canal and type I canal configuration. Mandibular canines are characterized by having more than one root and canal and alterations in root canal configurations compared to maxillary canines.

Frequency of non-single canals in mandibular premolars and correlations with other anatomical variants: an in vivo cone beam computed tomography study

Background

A 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).

Methods

A 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.

Results

PM2 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).

Conclusions

The 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.

Root and root canal diversity in human permanent maxillary first premolars and upper/lower first molars from a 14th-17th and 18th-19th century Radom population

OBJECTIVE

The aim of this study was to assess whether analyzed groups from two historical periods: Late Medieval (LMP), and Modern (MP) from Radom varied in the number of tooth roots and root canal system morphology.

METHODS

Root morphology of 229 permanent human teeth were analyzed using Cone Beam Computed Tomography. Additionally, the mitochondrial DNA (mtDNA) of 29 individuals from the LMP and 31 from the MP was analyzed.

RESULTS

In LMP, the maxillary first premolars were dominated by one root, while in MP second and third roots also appeared. Maxillary first molars in LMP presented three roots, while two-rooted forms occurred in MP. All mandibular first molars from the LMP and almost all (98%) from MP presented two roots. The greatest diversity in terms of root canal number occurred in one-rooted maxillary first premolars, the mesiobuccal root of the maxillary first molars, and the mesial and distal roots of the mandibular first molars in both groups. A few haplogroups from outside Europe (C, N, and R) were recorded in the MP Radom population. Moreover, this population had substantially higher haplogroup diversity compared with the LMP population.

CONCLUSION

Odontological research indicates an increase in the diversity in the number of roots and the shape of root canals in MP. This information corresponds to genetic research, which also indicates an increase in the diversity of haplogroups during the MP.

Surgically-oriented anatomical study of mandibular premolars: A CBCT study

Background

The knowledge of root canal anatomy and of the anatomical relationship should be considered mandatory when planning surgical endodontics. The aim of the study was to investigate the anatomical features of mandibular premolars, evaluating their relationship with mental nerve.

Material and Methods

CBCT scans were evaluated recording the number of roots, root canal configuration and the relationship with mental nerve of 100 mandibular premolars. After simulating a resection of 3 mm of the root, the shape and the number of canals, and the distance to the buccal and lingual bone plate and to the mental foramen was evaluated.

Results

The one root - one canal configuration was the most common configuration. The mental foramen was located at the level of MSPs in 40% cases, and it was between MSP and MFP in 46% of cases. The distance between the apex and the vestibular plate was lower than the distance to the lingual one.

Conclusions

We found a significant heterogeneity in the anatomy of mandibular premolars. CBCT could be considered important when planning surgical endodontics in this region. Key words:Cone-Beam Computed Tomography, bicuspid, root canal, root canal therapy, apicoectomy, mandibular nerve.

Cone-Beam Computed Tomographic Evaluation of Root Canal Morphology of Maxillary Premolars in a Saudi Population

Objective

The aim of the study was to investigate the root canal morphology of maxillary first and second premolars in a Saudi population using Cone-Beam Computed Tomography (CBCT).

Methods

This retrospective cross-sectional study assessed CBCT images of 707 Saudi patients. The number of roots and canal configuration were identified based on Vertucci's classification. Fisher's exact Chi-square tests were performed to analyze the association between sex and number of roots and sex and root canal configuration.

Results

Most teeth had two roots in maxillary first premolars (75.1%) and one root in maxillary second premolars (85.2%). Type IV was the most prevalent canal configuration in maxillary first premolars (69.1%), while Type I was the most in maxillary second premolars (49.4%). All types of canal configurations were observed in maxillary premolars except Type VII for the maxillary second premolar. Chi-square tests showed no significant association between gender and number of roots and sex and root canal configuration in both maxillary first and second premolars although higher number of roots was seen in men (P > 0.05).

Conclusion

Most maxillary first premolars had two roots with Type IV being the most predominant canal configuration, while a single root with Type I canal configuration was the most frequently observed morphology in maxillary second premolars. In maxillary first premolars, 21.3% had one canal apically, 75.4% had two canals apically, and 3.3% had three canals apically. In maxillary second premolars, 80.2% had one canal apically, 18.9% had two canals apically, and 0.9% had three canals apically.

Endodontic Management of Mandibular Second Premolar with Type IX Canal Configuration Using Cone-Beam Computed Tomography as a Diagnostic Aid: A Rare Case Report

Successful endodontic treatment requires knowledge of the root canal anatomy, cleaning, and shaping followed by three-dimensional filling of the root canals. With the advent of newer diagnostic aids such as cone-beam computed tomography (CBCT) and magnifying tools such as dental operating microscope and loupes, it has become easier for an operator to identify the root canal anatomy of teeth and reduce the risk of procedural accidents and failures. Variations in root canal configuration require modification in access cavity preparation, disinfection, and obturation of the canals. Mandibular premolars are identified to have unusual root and canal anatomy which increases the risk of endodontic failure when additional canals remain undiagnosed. The present case report elaborates successful endodontic management of a mandibular second premolar with Type IX root canal configuration using CBCT as a diagnostic tool.

Interrelationships in the Variability of Root Canal Anatomy among the Permanent Teeth: A Full-Mouth Approach by Cone-Beam CT

Objectives

In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The aim of this study was to assess using CBCT acquisitions regarding whether one root canal anatomy of a tooth is associated with a specific anatomy of another tooth.

Methods

A total of 106 CBCT acquisitions were obtained using a CBCT scanner with 200μm voxel size. Numbers of roots and canals of the entire dentition were described. Bivariate analyses and logistic regressions were conducted to explore root canal anatomy on one tooth according to age, gender, jaw, side and the others teeth. Multiple correspondence analysis (MCA) was performed to correlate the different numbers of canals profiles.

Results

A total of 2424 teeth were analyzed. Independently from the other variables, the presence of an additional root canal on a mandibular incisor increases the risk of having an additional root canal on a mandibular premolar (OR _[95%] 3.7 [1.0;13.2]). The mandibular molar variability increases in women compared to men (OR _[95%] 0.4 [0.1; 0.9]). MCA showed correspondence between 2-canals maxillary incisor and canines and 5-canals maxillary molars, and some correlation between additional canal on maxillary and mandibular premolars.

Conclusions

Although CBCT examinations are conducted in the first intention of making a diagnosis or prognostic evaluation, medium FOV acquisitions could be used as an initial database thus furnishing preliminary evaluations and information. In endodontic practice, clinicians should be aware of possible root canal anatomic variations. The visualization of all canals is considered essential in endodontic therapy. The use of multi-correspondence analysis for statistics in endodontic research is a new approach as a prognostic tool.

Differentiation of root canal morphology – a review of the literature

The morphological diversity of the inner anatomy of root canals in human permanent teeth is an issue mainly described in endodontics research. In recent years, it is a relatively new point in anthropological studies because it varies by sex, geographic and ethnic circumstances. An unusual number of root canals or their specific systems can differentiate populations around the world. The multiplicity of available methods for detecting root canal systems helps to better understand their complexity; however, most cannot be applied to anthropology due to limitations that occur in the bioarcheological material. Thorough knowledge of the heterogeneity and internal anatomy of the root canals supplies numerous classification systems proposed and improved over the years by many authors. A limited number of studies in the anthropological literature and future research will shed light onto the internal tooth morphology in historical populations. The aim of this paper is to describe various classification systems of root canals applied in endodontics. However, due to the often poor state of preservation and damage of archaeological derived remains, it seems that the best method is the approach that is the simplest and least complicated.

Anatomic symmetry of root and root canal morphology of posterior teeth in Indian subpopulation using cone beam computed tomography: A retrospective study

OBJECTIVE

To investigate the anatomic symmetry of maxillary and mandibular posteriors in Indian subpopulation using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images of 246 patients that had at least one noncarious, posterior tooth free of restorations in each quadrant were enrolled for retrospective analysis. A total of 3015 teeth (811 maxillary premolars, 845 mandibular premolars, 738 maxillary molars, and 621 mandibular molars) were analyzed for number of roots and root canals, canal morphology and anatomic symmetry, and concurrent types between the maxilla and mandible.

RESULTS

There was no difference in the percentage of symmetry for maxillary first (81.5%) and second (81.5%) premolars. Mandibular second premolars (98.3%) exhibited greater symmetry than mandibular first premolars (96.1%). First molars (77.5% and 82.1%) showed greater symmetry than second molars (70.8% and 78.6%), in both maxillary and mandibular arches, respectively. The most common anatomy observed were: maxillary first premolars - 2 roots with 2 canals, maxillary second premolars - 1 root with 2 canals, mandibular first and second premolars - 1 root with 1 canal, maxillary first and second molars - 3 roots with 4 canals, and mandibular first and second molars - 2 roots with 3 canals. When compared with any other teeth, maximum asymmetry was observed in maxillary second molar (29.2%).

CONCLUSION

The percentage of symmetry observed in the present study varied from 70% to 98% with least percentage of symmetry in maxillary second molars. These data should alert the clinicians while treating homonymous teeth of the same patient.

Gender difference and root canal morphology in mandibular premolars: A cone-beam computed tomography study in an Iranian population

BACKGROUND

Mandibular premolars are of the most difficult teeth to treat endodontically.

AIMS

To compare the root canal morphology of mandibular premolars between two genders in an Iranian population.

SETTINGS AND DESIGN

Totally, 230 cone-beam computed tomography images of the mandibles belonged to 115 males and 115 females were evaluated in the three spatial planes.

MATERIALS AND METHODS

The total number of roots and canals in the mandibular premolars was counted, and the difference between males and females were analyzed.

STATISTICAL ANALYSIS

Data were analyzed using Chi-square test. The significance level was set as P < 0.05.

RESULTS

The majority of mandibular first and second premolars had one root (85.7% and 94.8%, respectively) and one canal (63.9% and 78.3%, respectively). The number of roots in the mandibular first premolars had statistically significant difference between two genders (P = 0.001). There was no significant difference between two genders in the number of roots (P = 0.208) and canals (P = 0.498) in the mandibular second premolars.

CONCLUSION

According to the results of this study, the root canal morphology in the mandibular first premolars had statistically significant difference between two genders.

Endodontic management of a maxillary molar with three mesiobuccal canals

It is imperative that the clinician should have comprehensive knowledge about the normal anatomy and its variations of the teeth as the deviations from the usual are very common. An increased awareness of unusual anatomy and a better understanding of the root canal system guide the clinician in accurate diagnosis and treatment of such variations in order to achieve a successful endodontic outcome. The maxillary first molar has been shown to have a wide variation in respect to the number of canals specifically noted in the mesiobuccal root. The current case report shows the successful management of a maxillary molar in which the mesiobuccal root had three canals.

Endodontic treatment of a mandibular second premolar with three roots and three canals

Complex root canal system with atypical variations is a common finding among mandibular premolars. Endodontic treatment in these teeth may not be successful due to the failure to recognise and treat multiple canals. This paper presents endodontic treatment of a mandibular second premolar with three roots and three canals.

Endodontic and clinical considerations in the management of variable anatomy in mandibular premolars: a literature review

Mandibular premolars are known to have numerous anatomic variations of their roots and root canals, which are a challenge to treat endodontically. The paper reviews literature to detail the various clinically relevant anatomic considerations with detailed techniques and methods to successfully manage these anomalies. An emphasis and detailed description of every step of treatment including preoperative diagnosis, intraoperative identification and management, and surgical endodontic considerations for the successful management of these complex cases have been included.