A Cone-Beam Computed Tomography Scanning of the Root Canal System of Permanent Teeth among the Moscow Population

Systematic review and meta-analysis of root morphology and canal configuration of permanent premolars using cone-beam computed tomography

INTRODUCTION

The efficacy of root canal treatment is greatly impacted by a thorough understanding of root canal anatomy. This systematic review and meta-analysis aim to thoroughly investigate the root morphology and canal configuration (RMCC) of permanent premolars (PMs).

METHODOLOGY

A comprehensive analysis was conducted following the PRISMA guidelines. Literature exploration was carried out across four electronic databases (PubMed, Embase, Cochrane, and Web of Science). The risk of bias assessment was conducted for the included studies utilizing the Anatomical Quality Assessment (AQUA) tool. Data analysis was performed utilizing SPSS and RevMAN5.3.3. The meta-analysis was applied with a 95% confidence interval to calculate odds ratios (OR).

RESULTS

Among the 82 selected studies, 59 studies exhibited potential bias in domain one (objective(s) and subject characteristics), followed by domain three (methodology characterization). The majority of maxillary PM1s had either single root (46.7%) or double roots (51.9%), while three-rooted variants were uncommon (1.4%). Conversely, most other PMs exhibited a single root. In terms of canal configuration, maxillary PM1s predominantly featured double distinct canals (87.2%), with the majority of maxillary PM2s displaying either a single canal (51.4%) or double canals (48.3%). Mandibular PMs were primarily characterized by single canals, accounting for 78.3% of mandibular PM1s and 90.3% of mandibular PM2s. Subgroup analyses revealed higher incidences of single-rooted and single-canalled PMs among Asians compared to Caucasians. Additionally, women exhibited a higher incidence of single-rooted PMs, while men showed a greater frequency of double-rooted PMs.

CONCLUSIONS

The comprehensive analysis indicated that maxillary PM1s predominantly possess double roots and double canals, whereas maxillary PM2s and mandibular PMs were primarily characterized by single-rooted with a single canal. Notably, single root and single canal were more prevalent among women and Asian samples.

Micro-computed tomographic analysis of the morphology of maxillary lateral incisors

OBJECTIVE

This study aimed to investigate the morphology of maxillary lateral incisors (MxLI) using micro-computed tomography (micro-CT).

MATERIALS AND METHODS

The root canal configurations (RCC) of maxillary lateral incisors (MxLI) of a mixed Swiss-German population were examined using micro-CT, 3D imaging, and a 4-digit system code indicating the main root canal from coronal to apical thirds and the main foramina number.

RESULTS

The most frequently observed RCC of MxLI were 1-1-1/1 (Vertucci I/Ve I, 80.0%), 1-1-2/2 (Ve V, 7.3%), 1-2-1/1 (Ve III, 6.4%), 2-1-1/1 (Ve II, 1.8%), and 1-1-1/2 (1.8%)(n = 110). Three additional RCC were observed less frequently (0.9%). The MxLI showed one physiological foramen in 89.1%, two in 9.1%, and seldom three (1.8%). Most accessory canals were identified in the apical third of a root (20.0%), and no accessory canals in 72.7% of the samples.

CONCLUSIONS

Detailed information on the internal morphology of MxLI of a Swiss-German population is given. The most frequently observed RCC of MxLI is 1-1-1/1 (Ve I). However, accessory canals may occur in all apical thirds, and 20% of all teeth investigated showed a challenging RCC for clinical treatment.

CLINICAL RELEVANCE

This study offers clinicians comprehensive data on MxLI morphology, emphasizing the significance of understanding varied RCC and accessory canal presence for improving root canal treatment outcomes. Over 25% of teeth exhibited complex RCC or accessory canals, influencing decisions during root canal treatment.

The global prevalence of middle mesial canal in mandibular first and second molars assessed by cone beam computed tomography: A systematic review and meta-analysis

BACKGROUND

This meta-analysis sought to identify the in vivo prevalence and influencing factors of middle mesial canal (MMC) in mandibular first and second molars based on cone-beam computed tomography (CBCT) scans.

METHODS

MEDLINE/PubMed, Web of Science, Scopus, SciELO, Google Scholar databases/search engines were searched in period between 15^th and 21^st November 2022, to retrieve the in vivo CBCT-based studies that assessed the prevalence of MMC in mandibular first and/or second molars. The studies were strictly assessed using pre-defined inclusion and exclusion criteria for relevancy and eligibility through screening the title and abstract, and then assessed through reading the full texts using the same criteria. Subsequently, the fulfilled studies were assessed qualitatively using the Newcastle-Ottawa Quality Assessment Scale, and quantitatively using meta-analysis to calculate the pooled prevalence rates of MMC. The publication bias was assessed using funnel plot and Egger's test.

RESULTS

Out of 1,122 studies, 33 studies comprised 13,349 and 7,624 mandibular first and second molars, respectively, were eligible for inclusion. Twenty studies scored high quality, while thirteen scored moderate quality. The global prevalence of MMC in the first molar was 4.4% (95% CI = 0.035-0.053, P<0.001), significantly higher than that of the second molar which was 1.3% (95%, CI = 0.008-0.018, P<0.001). Gender, molar side, and age were not influencing factors of MMC prevalence.

CONCLUSION

The prevalence of MMC is not uncommon, being higher in the mandibular first molar compared to the mandibular second molar. The prevalence of MMC is not influenced by age, molar's side, and gender.

Root and canal morphology of mandibular second molars in an Egyptian subpopulation: a cone-beam computed tomography study

BACKGROUND

This study was using Cone beam computed tomography (CBCT) to examine the anatomical variations in mandibular second molars in an Egyptian sub-population.

METHODS

A total of 350 CBCT images (215 females and 135 males, aged 15-65 years) of mandibular second molars were evaluated. Samples were evaluated in terms of: number of roots, number of root canals, roots' cross section as well as prevalence and configurations of C-shaped canals. Statistical analysis was done to highlight differences between different categories and their prevalence among genders (significance level was set at p < 0.05). Data were presented as frequency and percentage values and were analyzed using chi square test followed by pairwise comparisons utilizing multiple Fisher's exact tests with Bonferroni correction. The significance level was set at p < 0.05 within all tests.

RESULTS

Of the 350 mandibular second molars evaluated, 87.2% were non-C-shaped while 12.8% were C-shaped with no gender-based statistically significant differences (χ2 = 0.19, p = 0.656). Most samples had three root canals (80%) followed by two (16%), then one (3.2%), and finally four (0.8%) root canals. Among the non-C-shaped molars, presence of two roots was most common (83.4%) followed by presence of a single root (16.2%), and only one sample (0.2%) had three roots, and this had no correlation with gender (χ2 = 1.86, p = 0.431). In the mesial roots Type IV Vertucci was the most common configuration found (68.8%), while Type I was the most prevalent in the distal roots (91.8%). The long oval configuration was the most commonly found cross section in mesial roots while "oval" was the most prevalent in distal roots.

CONCLUSION

Egyptian sub-population shows highly variable morphological features in mandibular second molars, hence, CBCT is highly recommended on case-to-case conditions.

Variations of root and canal morphology of mandibular second molars in Chinese individuals: a cone-beam computed tomography study

BACKGROUND

The mandibular second molars demonstrate variations on root and canal morphology. The aim of this study was to investigate all the root canal morphology of mandibular second molars and analyze the morphological variations in patients by gender and age in a Chinese population use CBCT imaging.

METHODS

Cone-beam computed tomographic images of 1200 bilateral mandibular second molars were obtained from 600 patients (300 females and 300 males) who required a preoperative assessment for implant surgery, surgical removal of impacted teeth, orthodontic treatment, surgery of maxillofacial tumour and cysts or LeFort I osteotomy. CBCT images were divided into 5 groups according to age: "15-24 years", "25-34 years", "35-44 years", "45-54 years" and "≥ 55 years"; and 2 groups by gender: "females" and "males". The following information were recorded: the number of roots and canals and their morphology, the frequency and configuration of C-shaped canals by gender, age and position (left and right). The chi-square test was used to analyse differences between groups. P value of < 0.05 was considered statistically significant.

RESULTS

Of the 1200 teeth, 61% had two separate roots located mesiodistally, 35.6% had one C-shaped root. The 45.3% teeth had three canals in two-rooted mandibular second molars. The mesial root showed a Vertucci type II configuration in 28.9% cases followed by type IV(24.4%). While the distal root showed a significant higher prevalence of type I configuration in 95.6%. In the examined 1200 teeth, 430 teeth (35.8%) had C-shaped root canals. The prevalence of C-shaped root canal systems was significantly higher in females (42.5%) than in males (29.1%) (P = 0.000), and did not differ with age (P = 0.126). The 80.4% C-shaped canals were bilateral (P = 0.000) and did not differ with side (left and right) (P = 0.758).

CONCLUSIONS

The most commonly observed root morphology for the mandibular second molars was 2 separate roots with three canals.The prevalence of C-shaped root canal is 35.8% and is more higher in females than in males.

A Cone-Beam Computed Tomography (CBCT) Study of Root Anatomy, Canal Morphology and Bilateral Symmetry of Permanent Maxillary Premolar Teeth Among the Qatari Subpopulation

Objectives:

The study aims to evaluate the root anatomy, canal morphology, and symmetry of maxillary premolars teeth in a Qatari subpopulation using cone-beam computed tomography (CBCT).

Materials and Methods:

544 CBCT images of Qatari patients were analyzed by two endodontists. Tooth position, number of roots, canal configuration, and number of canals per root were investigated. A chi-square test was used to evaluate the association between gender and the number of roots. The interexaminer and intraexaminer were performed and documented.

Results:

The most common root anatomy and canal morphology observed in maxillary first premolars (MFP) were two roots (70.6%) with a single canal per root, while in maxillary second premolars (MSP), there was one root (84.3%) with a single canal (83%).

Type I Vertucci morphology was predominated in all roots of two-rooted MFP (97%), three-rooted MFP (100%), single-rooted MSP (42%), and two-rooted MSP (100%). The Chi-square test showed an association between gender and number of roots in both MFP and MSP, with a higher number of roots seen in men(P<0.05).

A symmetrical pattern was observed in the number of roots and canals in both maxillary premolars. But the symmetry for the type of canal configuration is higher in MFP (78%) than MSP (54%).

Conclusion:

In the Qatari subpopulation, most MFP had two roots with a predominance of type I Vertucci, while MSP had one root with type I. Contralateral MSP showed more diversity in canal configuration that should be considered during root canal treatment. CBCT is an effective diagnostic tool to investigate root anatomy and canal morphology.

Endodontic Management of Mandibular Second Premolar with Vertucci Root Canal Configuration Type V

The diversity of root canal anatomy in permanent dentition is quite common. Understanding the basic anatomy of the root canal morphology and its variations is particularly important for successful root canal treatment. Mandibular second premolar usually consists of a single root with a single root canal. The presence of split roots in the apical third of the root with two separate root canals is quite rare. The major cause of endodontic failure in missed canals is that it harbors bacteria and other microorganisms. Careful radiographic interpretation and clinical examination of the pulp chamber will be helpful in locating canal orifices. The mandibular premolars with Vertucci type V canal configuration pose a challenge in clinical management. Identifying them early is important to aid appropriate modification in treatment protocol. In this case report, important modifications of clinical steps and application of magnification for successful management with access chamber modification are explained.

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.

Prevalence of Three-Rooted Deciduous Mandibular Molars in the Children of Northwestern Iran

Introduction

Although primary teeth have a determinative role in development of normal occlusion, few studies about anomalies related to deciduous dentition have been conducted so far. Regarding recent improvements in common knowledge and the importance of maintaining primary teeth until eruption of succedaneous teeth, identifying the morphology of primary teeth and probable variations is of great importance to achieve optimal therapeutic outcome. This study aims to determine the prevalence of three-rooted mandibular primary molars in a population of northwestern Iran.

Materials and Methods

In this descriptive cross-sectional study, periapical radiographs of patients attending private oral and maxillofacial radiology offices in the northwestern region of Iran from 2017 to 2019 were retrospectively reviewed. A total of 300 cases in the 3-10-year age range having bilateral periapical radiographs from mandibular primary molars were screened. First and second primary molars were observed meticulously. Gender, side of the mandible (right or left), symmetry, overall prevalence, and prevalence considering the type of molar (D or E) were recorded and analyzed.

Results

Overall prevalence of three-rooted mandibular primary molars was 9.33% ( 28/300), 92.9% of which were unilateral. The prevalence of teeth showing supernumerary roots among all teeth examined was 2.5% (30/1200). Considering symmetry and gender, the occurrence of these three-rooted primary molars did not differ significantly (respectively, p=0.832 and p=0.541). However, there was a significant relationship between the occurrence of supernumerary roots and left side for three-rooted first molars and right side for three-rooted second molars (p=0.021).

Conclusion

Obtained data show that three-rooted mandibular primary molars in children of northwest region of Iran have a prevalence of approximately 10 % which urges some specific considerations in exodontic and endodontic procedures.

Root canal morphology of the mandibular second premolar: a systematic review and meta-analysis

Background

The aim of this paper was to systematically review the root canal configuration (RCC) and morphology literature of the mandibular second premolar (Mn2P).

Methods

Systematic research of five electronic databases was performed to identify published literature concerning the root canal configuration (RCC) of the Mn2P up through July 2020. Studies were selected according to predefined search terms and keywords inclusion criteria: “root canal configuration”, “root canal system”, “root canal morphology”, “mandibular second premolar”, “mandibular premolars”, “morphology” and “anatomy”. Further possible studies were identified by cross-referencing and screening the bibliographies of the selected articles.

Results

From 1622 retrieved studies, 44 studies investigating the internal morphology of 17,839 Mn2Ps were included. Most examined Mn2Ps were single-rooted (89.5–100%); two-rooted (0.1–8%) and three-rooted (0.1–3.5%) Mn2Ps at lower frequency. Most frequent RCCs reported were 1–1–1/1 (55.3–99.6%) followed by 1–1–2/2 (0.5–57%) and 2–2–2/2 (0.6–18%). The meta-analysis of seven studies demonstrated that a significantly higher number of RCC type 1–2–1/1 (OR [95%CI] = 2.05 [1.27, 3.33]) and 2–2–2/2 (OR [95%CI] = 2.32 [0.65, 8.63]) were observed in male than in female patients.

Conclusions

Different RCC research methods have been reported. Whereas clearing and radiographs were commonly used in the past, CBCT has been prevalent in recent years. A globally high frequency of a 1–1–1/1 RCC in the Mn2P has been reported. Nevertheless, the probability that different, more complicated RCCs can appear in Mn2Ps should not be underestimated and, thus, should be taken into consideration when making decisions during an endodontic treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-021-01668-z.

Four-Rooted Maxillary First Molars: A Systematic Review and Meta-Analysis

Objectives

The majority of human maxillary first molars is usually described as having three roots, but different morphologies were documented in several studies and case reports. One very rare and less investigated anatomical anomaly is the occurrence of four radicular structures in the upper first molars. This communication aimed to define the prevalence of four-rooted maxillary first molars on a meta-analytical basis. The external and internal morphology of these teeth was described by the collection of published case reports.

Materials and Methods

Six electronic databases were accessed to collect case reports dealing with four-rooted maxillary first molars, as well as population-based cone-beam computed tomography (CBCT) studies. Afterward, the publications were selected according to predefined inclusion/exclusion criteria and evaluated using the Joanna Briggs Institute Critical Appraisal tool. The teeth of the chosen case reports were then independently analyzed by two dental professionals according to different dental classifications. Furthermore, the population studies were meta-analyzed to calculate the global and regional prevalence of four-rooted maxillary molars.

Results

Included were forty-nine population-based CBCT studies containing 26663 maxillary first molars. Upon these data, the global incidence of four-rooted maxillary molars was meta-analytically determined as 0.047% (95%-CI:0.011-0.103%). In combination with the case reports, it was pointed out that this anomaly is distributed worldwide. Furthermore, forty-eight case reports were included containing fifty-three maxillary molars with four roots. The analyzed teeth exhibited Versiani´s pulpal chamber floor Types A and B. The majority of four-rooted maxillary first molars were classified as Type I regarding Christie's configuration. But, also 7.54% of the altered teeth could not be described by this classification. 62.34% exhibited four root canals, but also variations with five, six, or seven canals were identified. Furthermore, a significant difference was found in the occurrence rate between male and female patients.

Conclusion

Due to the worldwide occurrence, dental professionals should be aware of this rare anomaly to avoid treatment errors, especially during endodontic or surgical therapies.

Imaging Anatomy of the Jaw and Dentition with Cone Beam Computed Tomography

Knowledge of dental, maxillary, and mandibular anatomy and the use of correct nomenclature is critical in the evaluation of a mandibulofacial and/or maxillofacial imaging data set. The use of the correct diagnostic imaging tool tailored to the patient's needs is of equal importance. This article highlights imaging anatomy and cross-sectional imaging modalities mainly focusing on cone beam computed tomography of the mandibulofacial and maxillofacial region.

Root Canal Morphology of 116 Maxillary Second Premolars by Micro-Computed Tomography in a Mixed Swiss-German Population with Systematic Review

INTRODUCTION

The aim of this investigation was to examine the root canal system morphology of maxillary second premolars (Mx2Ps) of a Swiss-German population by means of micro-computed tomography and provide systematic review of the root canal configuration (RCC) literature of Mx2Ps.

METHODS

The RCC, main foramina as well as accessory canals and foramina frequency of 116 Mx2Ps, were investigated by means of micro-computed tomography and 3-dimensional software imaging. The RCC from the coronal to apical thirds of the root as well as the main foramina number were described by using a four-digit system code. The literature review follows the PRISMA guideline analyzing randomized controlled trials and cross-sectional, cohort, comparative, validation, and evaluation studies on RCC in Embase, grey literature, PubMed, and Scopus.

RESULTS

Most frequently observed RCCs of Mx2Ps were 1-1-1/1 (35.3%), 1-1-1/2 (21.6%), and 2-1-1/1 (14.7%). Another 11 less frequent RCCs were observed. All Mx2Ps had 1 root. One main foramen was observed in 59.5% and two in 37.9%. Accessory foramina were observed in 46.6%. Thirty-one percent of the Mx2Ps showed accessory canals. One connecting canal between the buccal and palatal was observed in 12.1%.

CONCLUSIONS

Detailed RCC information of Mx2Ps in a Swiss-German population and the results of a systematic literature review of different populations and research methods used to investigate root canal morphology and configuration of Mx2Ps are given. Within the limitations of the study, a high RCC, connecting and accessory canals variability occur in maxillary second premolars.

Evaluation of Cross-Sectional Root Canal Shape and Presentation of New Classification of Its Changes Using Cone-Beam Computed Tomography Scanning

The root canal system is considering the most important factor in endodontic treatment, due to the complexity of its anatomy and morphology. The aim of this study was to evaluate the cross-sectional root canal shape in three thirds (coronal, middle, apical) in different age groups using cone-beam computed tomography scanning (CBCT) and to present a new classification for root canal shape changes. This cross-sectional study included 300 CBCT scans for patient aged 20–70, and these scans were evaluated to study the morphology of the cross-sectional root canal shape in coronal, middle, and apical thirds among three age groups, namely the young (20–44), middle (45–59), and elderly (60–70). The root canal shape was classified as round, oval, long oval, and ribbon (with or without isthmus). The cross-sectional root canal shape was identified in two groups: canals with an unchanging (constant) shape and canals with changing shape. In turn, in canals with changing shape, the change could be identified in the region of the middle or apical thirds of the canal. The results showed that root canal shape changes in two cases: (1) the presence of one or more canals in the root (with or without isthmus between them), and (2) with age, as it was observed that the cross-sectional shape of the root canal becomes round in the apical third with age. A new classification of the changes of root canal shape in three thirds (coronal, middle, apical) was presented in this study.