A new system for classifying tooth, root and canal anomalies

Nomogram to predict radicular grooves in maxillary lateral incisors in preoperative orthodontic population

OBJECTIVES

This study aimed to develop and validate a predictive nomogram for diagnosing radicular grooves (RG) in maxillary lateral incisors (MLIs), integrating demographic information, anatomical measurements, and Cone Beam Computed Tomography (CBCT) data to diagnose the RG in MLIs based on the clinical observation before resorting to the CBCT scan.

MATERIALS AND METHODS

A retrospective cohort of orthodontic patients from the School and Hospital of Stomatology, Wuhan University, was analyzed, including demographic characteristics, photographic anatomical assessments, and CBCT diagnoses. The cohort was divided into development and validation groups. Univariate and multivariate logistic regression analyses identified significant predictors of RG, which informed the development of a nomogram. This nomogram's performance was validated using receiver operating characteristic analysis.

RESULTS

The study included 381 patients (64.3% female) and evaluated 760 MLIs, with RG present in 26.25% of MLIs. The nomogram incorporated four significant anatomical predictors of RG presence, demonstrating substantial predictive efficacy with an area under the curve of 0.75 in the development cohort and 0.71 in the validation cohort.

CONCLUSIONS

A nomogram for the diagnosis of RG in MLIs was successfully developed. This tool offers a practical checklist of anatomical predictors to improve the diagnostic process in clinical practice.

CLINICAL RELEVANCE

The developed nomogram provides a novel, evidence-based tool to enhance the detection and treatment planning of MLIs with RG in diagnostic and therapeutic strategies.

Classifying the internal anatomy of anterior teeth in the Yemeni population using two systems: a retrospective CBCT study

A precursor for effective root canal treatment (RCT) is a complete understanding of the internal anatomy of teeth. In this study, the authors aimed to classify the root canal morphology of anterior teeth in the Yemeni population and identify gender-based variations among them. In addition, the symmetry among adjacent quadrants was also evaluated. Cone beam computed tomography (CBCT) scans of 2935 anterior teeth, 1502 maxillary, and 1433 mandibular were analyzed for root canal morphology and symmetry. Comparison between groups and among different genders was done using the Chi-square test. All the maxillary teeth were single-rooted and had a predominantly 1TN1 (Vertucci Type I) canal morphology. In addition to 1TN1, the presence of 1TN1-2-1 (Vertucci type III) and 1TN1-2-1-2-1 (not classified NC according to Vertucci) morphologies were noticed in the maxillary canines. Among the mandibular anteriors, the canal morphologies identified include 1TN1 in majority of the scans followed by 1TN2-1 (Vertucci II), 1TN1-2-1, 1TN1-2 (Vertucci V), 1TN1-2-1-2 (Vertucci VII) was seen only in incisors and newer canal types like 1TN2-1-2-1 (NC Vertucci) and 1TN1-2-1-2-1 (NC Vertucci) was seen in canines and lateral incisors. Two roots were only seen in the mandibular canines and classified as 2TN1-2 (NC Vertucci). Variations in root and root canal morphologies were seen among both genders. However, the results were not significant. All the maxillary teeth except 0.8% were bilaterally symmetrical. In mandible, symmetry ranged between 84.5 and 86.5%. In conclusion, single-rooted teeth with 1TN1 classification are most commonly seen in all the anterior teeth. Gender-based differences were non-significant, and bilateral symmetry was high. Ahmed et al. classification could precisely represent the root canal morphology in two rooted teeth.

Evaluation of calcium hydroxide root canal filling materials by cone beam computed tomography and three-dimensional modeling

AIM

The aim of this study was to compare the effectiveness of filling pastes in resin prototype primary molars by cone beam computed tomography (CBCT) and 3D modeling.

Endodontic management considerations for Type III dens invaginatus based on anatomical characteristics: A case series

Dens invaginatus (DI) is a developmental anomaly of the teeth characterised by the in-folding of the enamel into the dentin. Oehlers' Type III DI is the most serious form, in which the inherently invaginated channels communicate with periodontal and dental pulp tissue, increasing the risk of bacterial contamination. However, varying and complex anatomical features make diagnosis and treatment challenging. Conventional endodontic therapies promote healing by avoiding unnecessary interventions (e.g., surgical or other invasive treatments). Radiographic examination can reveal the structural details of such malformations. We obtained multiple procedural details for treating Type III DI based on radiographic analyses from our clinical experience. In addition, we introduce a new classification strategy for the management of Type III DI that is more applicable to treatment needs. This study aimed to discuss the anatomical features and current treatment considerations of Type III DI.

Characterization of the root and canal anatomy of maxillary premolar teeth in an Iraqi subpopulation: a cone beam computed tomography study

This study aims to evaluate the number of roots and root canal morphology types of maxillary premolars in relation to a patient's gender and age in an Iraqi population using two classification systems. Cone beam computed tomography (CBCT) scans of 1116 maxillary premolars from 385 patients were evaluated for the number of roots and root canal morphology types according to Vertucci's classification and Ahmed et al. classification systems. Differences in the number of roots and root canal morphology types with regard to tooth type, patients' gender and age groups were evaluated and the degree of bilateral symmetry was determined. Chi-squared test was used for statistical analysis. About 51.1% of the 1st premolars were double rooted. The majority (87.9%) of the 2nd premolars were single rooted. The three-rooted form presented in only 1.2% and 0.7% of the 1st and 2nd premolars, respectively. Vertucci Type IV (Ahmed et al. code 2MaxP B1P1) and Vertucci Type I (Ahmed et al. code 1MaxP1) were the most common canal morphology types in the 1st and 2nd premolars, respectively. Females showed a lower number of roots and a higher prevalence of Vertucci Type I configuration (P < 0.05). Younger age groups showed a higher prevalence of Vertucci Type I configuration (P < 0.05). Bilateral symmetry was seen in more than half of the maxillary premolars. There is a considerable variation in the number of roots and root canal configurations of maxillary premolars in the studied Iraqi population, with a significant difference by gender and age groups. Ahmed et al. classification provided more accurate presentation of the root and canal anatomy in maxillary premolars compared to Vertucci's classification.

Cone-beam computed tomographic evaluation to estimate the prevalence of palatogingival groove in the maxillary anterior teeth and its radiographic characteristics: An institutional retrospective study

Aim

The purpose of the study was to radiographically evaluate the prevalence of palatogingival groove (PG) in the East Indian population in the maxillary anterior teeth in different genders, its unilateral/bilateral presentation, classified based on its radiographic characteristics, to determine the prevalence of different types, which could help in future treatment planning.

Study Design

The design of the study was a retrospective study.

Materials and Methods

Analysis of 429 maxillary anterior teeth (144 central incisors, 145 lateral incisors, and 139 canines) in 72 cone-beam computed tomography scans was done (31 males and 41 females, mean age 27.3 ± 7.63). Demographic details of patients and characteristics of PG, i.e. location, extension, depth, and type, were recorded. The presence of alveolar bone loss and periapical pathology was noted.

Results

An overall prevalence of PG was found to be 2.33% (n = 10), with PG being detected in 2 (1.388%) central incisors, 8 (5.51%) lateral incisors, and 0 (0%) canines. Eight of the patients had a unilateral presence, while one patient reported with bilateral presence, implying a significantly higher predilection of unilateral occurrence (P = 0.02). The prevalence was found to be higher in females (n = 8). The teeth were categorized as either having Type I (6 teeth), Type II (3 teeth), or Type III (1 teeth). Three of the 10 PGs were present in the mesial, six in the mid-palatal, and one in the distal portion of the palatal surface.

Conclusions

The prevalence of PG in the maxillary incisors in this cohort is 2.33%. The maxillary lateral incisors are the most affected teeth. Unilateral presentation is more common.

Internal and external morphological analysis of fused-rooted mandibular second molars in the Chinese population: A micro-computed tomographic study

This study investigated the root canal morphology of fused-rooted mandibular second molars based on the pulp chamber floor (PCF) and analysed the correlation between the external morphology of the radicular groove, and the internal morphology of the PCF and root canal configuration. A total of 291 fused-rooted teeth collected from the Chinese population were scanned using micro-computed tomography and a dental operating microscope was used for observing the PCFs. The classification of the PCF and root canal configuration were identified according to modified Min et al.'s and Gao et al.'s classifications, respectively. Additionally, a new radicular groove classification was proposed. The correlation among these morphological characteristics was investigated using the chi-square test and Fisher's exact test (p < 0.05). The results showed that 74.2% of teeth had C-shaped PCFs, while 21.0% had non-C-shaped PCFs. As for the root canal configurations, 37.5% of teeth were merging type, 40.9% were symmetrical type, and 14.8% were asymmetrical type. Statistical analysis revealed a significant correlation between the PCF types and the root canal configurations (p < 0.001). The dominant root canal types for teeth with C-shaped PCFs were merging and symmetrical types, while the asymmetrical type was not identified in non-C-shaped PCFs. In addition, significant morphological association between the root canals and radicular grooves was also revealed (p < 0.001). Teeth with different PCF morphologies exhibit specific patterns of root canal category distribution. Understanding the morphological nuances of the root canal based on the PCF can assist clinicians in predicting and identifying the canal configuration beneath the visible orifice.

Critical analysis of a new system to classify root and canal morphology - A systematic review

A novel system to classify root and canal morphology was recently introduced (Ahmed et al. 2017). This systematic review aimed to answer the following research question: Does the Ahmed et al. system provide a more accurate and practical classification of root and canal anatomy compared to other classifications? A literature search was conducted in Google Scholar, Scopus and Wiley Online Library to identify the citation counts for the article entitled 'A new system for classifying root and root canal morphology; doi.org/10.1111/iej.12685'. After removal of duplicates and unrelated articles, 15 studies were included and analysed. All studies compared the Ahmed et al. system with the Vertucci classification. Results revealed that both systems were able to classify simple canal configurations in single-rooted anterior and premolar teeth, disto-buccal and palatal roots of maxillary molars. However, the Ahmed et al. system provided more accurate and comprehensive categorisations of single-rooted teeth with complex canal anatomy, multi-rooted maxillary and mandibular premolars and the mesio-buccal root of maxillary molars. Further evidence on the utility of the Ahmed et al. system is required using other diagnostic devices especially in molars.

Internal Morphology of Mandibular Second Premolars Using Micro-Computed Tomography

To examine root canal morphology of mandibular second premolars (Mn2P) of a mixed Swiss-German population by means of micro-computed tomography (micro-CT). Root canal configuration (RCC) of 102 Mn2P were investigated using micro-CT unit (µCT 40; SCANCO Medical AG, Brüttisellen, Switzerland) with 3D software imaging (VGStudio Max 2.2; Volume Graphics GmbH, Heidelberg, Germany), described with a four-digit system code indicating the main root canal from coronal to apical thirds and the number of main foramina. A total of 12 different RCCs were detected. 1-1-1/1 (54.9%) was most frequently observed RCC, followed by 1-1-1/2 (14.7%), 1-1-2/2 (10.8%), 1-2-2/2 (4.9%), 1-1-3/3 (3.9%), 1-1-1/3 (2.9%), 2-1-1/1 (2.9%) and less frequently 1-1-2/3, 1-2-1/2, 2-1-2/2, 1-1-2/5, 1-1-1/4 with each 1.0%. No accessory foramina were present in 35.3%, one in 35.3%, two in 21.6%, three and four in 2.9%, and five in 2.0%. In 55.9% Mn2Ps, accessory root canals were present in apical third and 8.8% in middle third of a root. Connecting canals were observed less frequently (6.9%) in apical and 2.9% in the middle third, no accessory/connecting canals in coronal third. Every tenth tooth showed at least or more than three main foramina. Almost two thirds of the sample showed accessory root canals, predominantly in apical third. The mainly single-rooted sample of Mn2Ps showed less frequent morphological diversifications than Mn1Ps.

Implications of root, pulp chamber, and canal anatomy on pulpotomy and revitalization procedures

OBJECTIVES

This review aims to discuss the implications of anatomy of the root, pulp chamber, and canals on pulpotomy and revitalization procedures (RPs) as treatment alternatives to root canal treatment procedures.

METHODS

This narrative review was undertaken to address two main questions - why remove vital pulp tissue in teeth with complex canal anatomy when it can be preserved? And why replace the necrotic pulp in teeth with mature roots with a synthetic material when we can revitalize? This review also aims to discuss anatomical challenges with pulpotomy and revitalization procedures.

RESULTS

Maintaining the vitality of the pulp via partial or full pulpotomy procedures avoids the multiple potential challenges faced by clinicians during root canal treatment. However, carrying out pulpotomy procedures requires a meticulous understanding of the pulp chamber anatomy, which varies from tooth to tooth. Literature shows an increased interest in the application of RPs in teeth with mature roots; however, to date, the relation between the complexity of the root canal system and outcomes of RPs in necrotic multi-rooted teeth with mature roots is unclear and requires further robust comparative research and long-term follow-up.

CONCLUSIONS

Whenever indicated, pulpotomy procedures are viable treatment options for vital teeth with mature roots; however, comparative, adequately powered studies with long-term follow-up are needed as a priority in this area. RPs show promising outcomes for necrotic teeth with mature roots that warrant more evidence in different tooth types with long-term follow-ups.  CLINICAL RELEVANCE: Clinicians should be aware of the pulp chamber anatomy, which is subject to morphological changes by age or as a defensive mechanism against microbial irritation, before practicing partial and full pulpotomy procedures. RP is a promising treatment option for teeth with immature roots, but more evidence is needed for its applications in teeth with mature roots. A universal consensus and considerably more robust evidence are needed for the standardization of RPs in teeth with mature roots.

Management of Palatogingival Groove in Maxillary Lateral Incisor: A Report of a Rare Case With a Brief Review of Literature

Several morphological abnormalities may occur during tooth development and may be a predisposing factor for periodontal destruction. Palatogingival groove (PGG) is a developmental deformity that may cause localized periodontitis and endodontic complexities. The groove usually originates as a root indentation in the central fossa of the palatal root of maxillary lateral incisors. Cone beam computed tomography (CBCT) is an excellent radiographic imaging technique capable of identifying PGGs and provides details about the exact site, extent, and depth characteristics of this deformity. Early diagnosis and management of PGGs are of utmost importance, particularly due to their diagnostic intricacies that can pose both clinical and therapeutic challenges. This article aims to report a rare case of palatogingival groove associated with an on-and-off discharge from the maxillary left lateral incisor tooth (#22). Nonsurgical endodontic treatment was carried out with #22, and the palatogingival groove was sealed with composite restoration after a deep curettage. Excellent radiographic healing was observed after a six-month follow-up.

Effect of conventional needle irrigation, passive ultrasonic irrigation, sonic irrigation and XP-endo finisher in removing intracanal Vitapex paste

To compare the efficiency of conventional needle irrigation, passive ultrasonic irrigation, sonic irrigation and XP-endo Finisher in removing Vitapex paste from root canals. The root canals of human single-rooted teeth were prepared and obturated with Vitapex paste. After 2 weeks, the 48 teeth were randomly allocated into four groups: conventional needle irrigation (CNI) group, passive ultrasonic irrigation (PUI) group, sonic irrigation (SI) group and XP-endo Finisher (XP) group. The specimens of four groups were scanned using a micro-computed tomography after the Vitapex pastes was removed. The results showed that more residual paste was left in the CNI group than in the other three groups (p < 0.05). There was no significant difference among the PUI, SI and XP group (p > 0.05). And, the majority of the residual Vitapex was found in the apical third, with a small amount in the middle third after using any of the three agitated irrigation techniques.

A microcomputed tomographic analysis of the morphological variabilities and incidence of extra canals in mandibular first molar teeth in an Egyptian subpopulation

A well-protected microbial habitat may be present in the root and canal morphology, which is varied and complicated. Before initiating effective root canal treatment, a detailed knowledge of the root and canal anatomical variances in each tooth is a must. This study aimed to investigate the root canal configuration, apical constriction anatomy, location of the apical foramen, dentine thickness, and prevalence of accessory canals in mandibular molar teeth in an Egyptian subpopulation using micro-computed tomography (microCT). A total of 96 mandibular first molars were scanned using microCT, and 3D reconstruction was performed using Mimics software. The root canal configurations of each of the mesial and distal root were classified with two different classification systems. The prevalence and dentin thickness around middle mesial and middle distal canals were investigated. The number, location and anatomy of major apical foramina and the apical constriction anatomy analysed. The number and location of accessory canals were identified. Our findings showed that two separate canals (15%) and one single canal (65%) were the most common configuration in the mesial and distal roots, respectively. More than half of the mesial roots had complex canal configurations and 51% had middle mesial canals. The single apical constriction anatomy was the most common for both canals followed by the parallel anatomy. Disto-lingual and distal locations of the apical foramen are the most common location for both roots. Mandibular molars in Egyptians show a wide range of variations in root canal anatomy with high prevalence of middle mesial canals. Clinicians should be aware of such anatomical variations for successful root canal treatment procedures. A specific access refinement protocol and appropriate shaping parameters should be designated for each case to fulfil the mechanical and biological objectives of root canal treatment without compromising the longevity of treated teeth.

Root and canal anatomy of mandibular first molars using micro-computed tomography: a systematic review

BACKGROUND

A thorough understanding of root and canal anatomy is crucial for successful root canal treatment outcomes. This systematic review aims to explore the published micro-CT studies investigated the anatomy of root and canal system in permanent mandibular first molars.

METHOD

An electronic search was performed on Web of science, PubMed, and Scopus. Micro-CT journal studies investigated the root and canal anatomy of permanent double-rooted mandibular first molars were included. Data on study characteristics, objectives of interest, specifications of the studies, and micro-CT specifications were extracted. Risk of bias assessment (ROB) of the included studies was performed using Anatomical Quality Assessment (AQUA) tool. The extracted data were presented in tables and figures to present and synthesise the results. A meta-analysis was performed for the studies related to the prevalence of Vertucci's canal configurations, middle mesial canal (MMC) configurations, and Fan's isthmus types.

RESULTS

Amongst 1358 identified studies, thirty met the inclusion criteria. In terms of the objectives, the selected studies showed high anatomical variability in mandibular first molars. Twenty-two (73%), 25 (83%), and 12 (40%) of the studies reported the population/ethnicity, micro-CT specifications, and ethical approval, respectively. 28 (93%) studies did not disclose the method of sample size estimation. In only 6 (20%) of the studies, the authors had calibrated the assessment approaches. Mostly, a potential ROB was reported in domain 1 (objective(s) and subject characteristics) and domain 3 (methodology characterization). Whilst, low risk was reported in domains 2 (study design), 4 (descriptive anatomy), and 5 (reporting of results). The overall ROB was reported to be ''moderate'' in the vast majority of the studies (27/30). Meta-analysis results showed high levels of heterogeneity among the studies related to MMCs (I² = 86%) and Fan's isthmus (I² = 87%). As for the root canal configuration, pooled prevalence showed that Vertucci type IV and type I were the most prevalent in mesial and distal root canals, respectively.

CONCLUSION

Based on moderate risk of bias level of evidence, micro-CT studies have shown wide range of qualitative and quantitative data presentations of the roots and canals in mandibular first molars. Protocol and registration. The protocol of this systematic review was prospectively registered in the Open Science Framework database ( https://osf.io ) on 2022-06-20 with the registration number 10.17605/OSF.IO/EZP7K.

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.

Revisiting Premolars Using Cone-Beam Computed Tomography Analysis and Classifying Their Roots and Root Canal Morphology Using Newer Classification

OBJECTIVE

The objective is to compare the internal morphology of premolars while applying the Vertucci and recent classification system for root canal variations in the Gujarat population using CBCT.

MATERIALS AND METHODOLOGY

 A sample size of 537 CBCT images collected from various diagnostic centers in Gujarat was analyzed. The root canal morphology was then classified by using two methods - Ahmed et al. and Vertucci classification system. Fisher's exact test and Chi-square test were used for statistical analysis.

RESULTS

All the premolars revealed a varied canal configuration. More than half of maxillary first and 42% of maxillary second premolars were double rooted. Vertucci type IV classification was the most common in first maxillary premolars and Type I and type IV were commonly seen in second premolars. According to the new system, the code ²N B¹ P¹ was commonly seen for first maxillary premolars. The majority of mandibular premolars were single rooted. Classification wise type I Vertucci and ¹ N¹  were the most common types observed.

CONCLUSION

 Premolars - both maxillary and mandibular - in this subpopulation had a wide range of root canal anatomical variations. Clinicians should be aware of this for a successful treatment outcome. The new system for classifying canal morphology describes the root and canal configurations in a more accurate and practical manner compared to the Vertucci classification and hence can be used routinely.

Variation in location of the distobuccal root canal in a permanent maxillary second molar: A case report

Key Clinical Message

Clinicians should be aware of the variations in the number of roots and root canals and the peculiar or eccentric location of root canals. An intraoperative CBCT can be very useful in improved visualization of the anatomical variations.

Abstract

This case report describes the unusual location of the distobuccal root canal in a maxillary second molar with root fusion. On access opening, three distinct root canal orifices, the mesiobuccal canal, palatal canal, and a third orifice closer to the palatal canal, were seen, giving an illusion of an additional palatal canal. An attempt was made to search for the distobuccal canal in its usual position, leading to the gouging of the pulp chamber floor. An intraoperative limited field of view cone-beam computed tomography (CBCT) revealed the root orifice adjacent to the palatal canal was the distobuccal canal. CBCT also revealed fusion of both the buccal and palatal roots in the root's coronal and middle third region, but they were not fused apically.

Prevalence of taurodontism in individuals in Northwest China determined by cone-beam computed tomography images

Objective

The aim of this retrospective study was to evaluate the prevalence of taurodontism in a group of adult dental patients in Northwest China with the aid of cone-beam computed tomography (CBCT).

Methods

This study used Shifman and Chanannel's criteria to statistically analyze the prevalence of taurodontism in the premolars and molars of the Chinese population. CBCT images of 5488 teeth from 580 subjects of Chinese origin were evaluated. The measured data were statistically analyzed and the chi-square test was also used to compare the prevalence of taurodontism between male and female subjects and between the upper and lower jaws (P < 0.05).

Results

Taurodontism was detected in 169 patients, with a prevalence of 29.14%, of which 27.24% were males and 30.65% were females. The chi-square test showed that there was no significant difference between males and females (P > 0.05). Taurodontism was found in 7.45% of all teeth examined. Taurodonts were significantly more common in the maxilla (9.06%) than in the mandible (5.15%) (P < 0.001), and the maxillary second molar (25.18%) was the most common tooth affected. According to morphology, hypotaurodonts were the most common (60.39%) among taurodontic teeth.

Conclusions

Taurodontism was relatively common in the Chinese population and was almost equally distributed between males and females. The maxillary second molar was the most common tooth of all taurodonts measured, and taurodonts were significantly more common in the maxilla than in the mandible. Hypotaurodontism was the most common form of taurodontism. Our study provides a reference for dental deformities in the Chinese population and the diagnosis and treatment of taurodontism.

Morphological analysis of anterior permanent dentition in a Chinese population using cone-beam computed tomography

PURPOSE

Morphological analysis of permanent anterior dentition is essential for achieving an ideal treatment outcome and avoiding unnecessary failure. This study aimed to analyze the morphologies of anterior teeth in the Chinese population in depth.

METHODS

In this retrospective study, 4309 anterior teeth from 401 Chinese patients were investigated using cone-beam computed tomography (CBCT) from 2019-2021. We summarized the morphological characteristics of the anterior teeth in terms of the root length, cementoenamel junction curvature (CEJ-C), root furcation and canal variations.

RESULTS

We found that the root lengths of the maxillary anterior incisors were similar (13.3 mm), while the root lengths of the mandibular central (12.2 mm) and lateral incisors (13.4 mm) varied significantly (p < .0001). Both the maxillary (16.6 mm) and mandibular canines (15.5 mm) were found to have greater root lengths than the corresponding incisors (p < .0001). The CEJ-C was significantly greater around incisors (2.5 mm) than around the canines (2.0 mm) in the maxilla (p < .0001), while the curvature remained similar in mandibular anterior teeth (1.8 mm). Root furcation was observed in mandibular canines and lateral incisors. Moreover, all types of Vertucci's classification in anterior dentitions were observed, while two other new types were found. Among them, the maxilla was only observed to exhibit types I, II, III, and ST II, while the mandible was found to exhibit almost all types. However, Type I still accounts for the majority of dentitions.

CONCLUSIONS

Morphological analysis of permanent anterior dentition revealed diversity in the tooth length, CEJ-C, furcation proportion, and canal variations. In general, mandibular anterior teeth showed a more complex structure than maxillary teeth.

A micro-computed tomographic analysis of the root canal systems in the permanent mandibular incisors in a Chinese population

BACKGROUND

Comprehensive understanding of the root canal system complexity is critical important for successful root canal therapy. A double root canal system may be present in permanent mandibular incisors with a variable incidence in different ethnic populations. Ignorance or improper management of this canal variation can lead to treatment failure. This in vitro study aimed to identify the anatomic features of root canal systems in the mandibular incisors in a Chinese population by using micro-CT.

METHODS

A total of 106 permanent mandibular incisors (53 central incisors and 53 lateral incisors) were collected from a native Chinese population. The teeth were scanned by a micro-CT scanner and then reconstructed three-dimensionally. The canal configurations were detected by Vertucci's classification, and the number and location of the accessory canals were also identified. The long (D) and short diameters (d) of the main and accessory canals were measured and D/d ratio was calculated at different root levels (cemento-enamel junction [CEJ] level, mid-root level and 1, 2, 3 and 4 mm from the apex). The root canal curvatures in the double-canaled mandibular incisors were measured at the proximal view by using modified Schneider's method. Chi-square test or Fisher's exact test was used for comparison of occurrence rates. Comparison of means from multiple groups was performed by using one-way ANOVA and LSD post-hoc test.

RESULTS

In regard to the occurrence of double root canals, gender difference was neither detected in the mandibular central (16.0% [male] vs 14.3% [female]; p = 0.862), nor in the mandibular lateral incisors (26.9% [male] vs 33.3% [female]; p = 0.611). Age group difference was also not detected in the mandibular central (p = 0.717) and lateral incisors (p = 0.521). The incidence of double root canals was 15.1% (8/53) in the central incisors, and 30.2% (16/53) in the lateral incisors, but the difference did not reach statistical significance (p = 0.063). The most frequent non-single canal type was the type III (1-2-1) (18.9% [20/106]), and the other types identified included 1 case of type II (2-1) and 3 cases of type V (1-2). The incidence of accessory canals was 17.9% (19/106), with a mean level of 1.92 ± 1.19 mm from the apex. The frequency of long-oval (2 ≤ D/d < 4) and flattened canals (D/d ≥ 4), as well as the mean value of D, d and D/d ratio increased from the apical 1 mm to the apical 4 mm level (the D/d ratio increased from 1.9 to 2.9 for the single canals, from 1.4 to 3.3 for the buccal canals and from 1.2 to 2.3 for the lingual canals), and the D/d ratio reached the peak at the mid-root level. Double curvatures were detected in 33.3% (8/24) of the buccal canals and 37.5% (9/24) of the lingual canals, and the difference has no statistical significance (p = 0.063). The degrees of the primary curvatures were 21.5 ± 7.1 degrees for the buccal and 30.1 ± 9.2 degrees for the lingual canals, and the degrees of secondary curvatures were 27.0 ± 11.4 degrees for the buccal and 30.5 ± 12.5 degrees for the lingual canals in the double curvatures. The degrees of the single curvatures were 14.2 ± 6.3 degrees for the buccal and 15.6 ± 6.0 degrees for the lingual canals. Significant difference was detected among above 6 groups of canal curvatures (p = 0.000), and severe curvatures (≥ 20 degrees) were more frequently detected in the double curved canals.

CONCLUSIONS

Double-canaled mandibular incisors were not uncommon in the Chinese population, and type 1-2-1 was the most frequent non-single canal type. Gender and age did not significantly impact the occurrence of a second canal in mandibular incisors. Long-oval and flattened canals were very common at different root levels and their incidence increased from apex to the mid-root level. Severe curvatures were frequently detected in the double canal systems, especially in those canals with double curvatures.

The Preventive Effect of A Magnetic Nanoparticle-Modified Root Canal Sealer on Persistent Apical Periodontitis

Persistent apical periodontitis is a critical challenge for endodontists. Developing root canal filling materials with continuous antibacterial effects and tightly sealed root canals are essential strategies to avoid the failure of root canal therapy and prevent persistent apical periodontitis. We modified the EndoREZ root canal sealer with the antibacterial material dimethylaminododecyl methacrylate (DMADDM) and magnetic nanoparticles (MNPs). The mechanical properties of the modified root canal sealer were tested. The biocompatibility of this sealer was verified in vitro and in vivo. Multispecies biofilms were constructed to assess the antibacterial effects of the modified root canal sealer. We applied magnetic fields and examined the extent of root canal sealer penetration in vitro and in vivo. The results showed that EndoREZ sealer containing 2.5% DMADDM and 1% MNP had biological safety and apical sealing ability. In addition, the modified sealer could increase the sealer penetration range and exert significant antibacterial effects on multispecies biofilms under an external magnetic field. According to the in vivo study, the apices of the root canals with the sealer containing 2.5% DMADDM and 1% MNP showed no significant resorption and exhibited only a slight increase in the periodontal ligament space, with a good inhibitory effect on persistent apical periodontitis.

A study of mandibular premolar root and canal morphology in a Black South African population using cone-beam computed tomography and two classification systems

PURPOSE

An investigation of the configurations of mandibular premolar roots and canals in a population of Black South Africans.

METHODS

Cone-beam computed tomography analysis of 772 mandibular premolars was performed, and the premolars were classified according to the systems proposed by Vertucci and Ahmed et al. Root number, canal morphology, age, and sex were recorded. Fisher's exact test was used to determine relationships based on age and sex (P < 0.05).

RESULTS

Single roots were seen in the majority of mandibular premolars (97.1%). Single canal configurations (i.e., Vertucci Type 1/Ahmed et al. ¹MP¹) were observed in 48.5% of first and 81.3% of second mandibular premolars. Mandibular first premolars demonstrated multiple canals in more than half of the sample (51.5%), and C-shaped morphology in more than one-tenth (11.1%). A relationship between sex and the presence of radicular grooves was demonstrated (P = 0.049), males being more likely to demonstrate this feature (P = 0.051). Multiple canals in mandibular first premolars also showed a relationship with sex (P = 0.005), a male predilection being evident (P = 0.007). The Ahmed et al. system proved superior to the Vertucci classification for reporting complex configurations and anatomical variations, although a greater number of unique categories were created.

CONCLUSION

Diverse mandibular premolar root and canal morphology was observed in the studied population. Clinicians must be aware of common morphological features as well as possible anatomical variations in mandibular premolars, as failure to treat complete root canal systems may negatively impact endodontic treatment outcomes.

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.

Assessing Efficacy of Clinical Disinfectants for Pathogenic Fungi by Single-Cell Raman Microspectroscopy

Disinfectants are crucial for root canal therapy (RCT), as metabolism of canal-inhabiting microbes can cause refractory infections. To develop effective yet patient- and environment-friendly disinfectant formulations, we quantitatively assessed the metabolism-inhibiting effects of intracanal disinfectants via D₂O-probed Single-Cell Raman Spectra (SCRS), using Candida albicans (C. albicans) as a pathogen model. For chlorhexidine gluconate (CHX), sodium hypochlorite (NaClO), and hydrogen peroxide (H₂O₂), at their MIC of 4, 168, and 60 μg/ml, respectively, despite the complete growth halt, metabolic activity of individual fungal cells was reduced on average by 0.4%, 93.9%, and 94.1% at 8 h, revealing a “nongrowing but metabolically active” (NGMA) state that may underlie potential refractory infections, particularly for CHX. In contrast, at their Metabolic Activity-based Minimum Inhibitory Concentrations (MIC-MA) of 8, 336, and 120 μg/ml, respectively, metabolic activity of all cells was completely halted throughout 8 h exposure. Moreover, combined use of NaClO+H₂O₂ (combination at 0.5× MIC-MA each) outperforms solo uses of CHX, NaClO, H₂O₂, or other binary combinations. Furthermore, dynamics of SCRS revealed distinct fungicidal mechanisms of CHX, NaClO, H₂O₂, and their pairwise combinations. MIC-MA is advantageous in critically assessing antifungal efficacy, and NaClO+H₂O₂ can potentially serve as a more efficient disinfectant formula for fungal pathogens.

Anatomical Evaluation of Mandibular Premolars in Saudi Population: An In Vivo Cone-beam Computed Tomography Study

Background:

Cone-beam computed tomography (CBCT) offers a three-dimensional (3D) image of the anatomical structures in the maxillofacial region. CBCT can provide images with sufficient spatial resolution and low radiation dose in endodontic diagnosis and treatment planning.

Objective:

This study aimed to evaluate the root canal morphology of mandibular premolars in a Saudi sub-population by showing the importance of cone-beam computed tomography radiographic analysis in detecting varieties of the root canal system.

Methods:

A total of 776 mandibular first and second premolars were analyzed. Teeth that have completed root development and apical closure were included. To accurately evaluate the external and internal morphologies of the teeth, three sections (i.e., the serial axial, coronal, and sagittal sections) were acquired for each tooth. Data are presented in terms of frequencies and percentages. The chi-squared test was used to determine the differences between two sides (right and left). A p-value of less than 0.05 was considered statistically significant.

Results:

Among the 397 mandibular first premolars, 99.5% had one root, 69.5% had one canal, and 29.5% had two canals. In terms of root canal configuration, 69.5%, 6.3%, 22.2%, and 0.3% of the teeth had Vertucci type I, type III, type V, and type VII canal configurations, respectively. Similarly, among the mandibular second premolars, 100% had one root, 96.8% had one canal, and 2.1% of teeth had two canals. Most of the samples (96.8%) had Vertucci type I canal configuration, and 1.6% and 0.8% of the teeth had Vertucci type III and type V canal configurations, respectively. In both groups of teeth, no statistically significant differences were observed between the right and left sides (P> 0.05).

Conclusion:

Mandibular premolars could have challenged internal morphology, and CBCT small field of view is advised in case periapical x-ray is inconclusive.

Atypical Radicular Anatomy in Permanent Human Teeth: A Systematic Review

The aim of the present study is to classify and quantify the anatomical variations of teeth in terms of form and number of root canals reported in human teeth employing the classification systems proposed previously. An electronic (PubMed) and manual search were performed to identify case reports noting any of the anatomical variations. Each alteration was studied independently. The electronic search was performed using the following keywords: anatomical aberration, root canal, permanent Dentition, case report, c-shaped canal, dens invaginatus, palato-radicular groove, palato-radicular groove, palato-gingival groove, radix entomolaris, dental fusion, dental gemination, taurodontism, dilaceration. The initial search revealed 1497 papers, of which 938 were excluded after analyzing the titles and abstracts. Therefore, 559 potential papers were considered. Of those, 140 articles did not meet the inclusion criteria. For the final revision, 419 papers were considered. We found that the mandibular first premolar had the highest prevalence of C-shaped canals. Dens invaginatus was more frequently found in the mandibular lateral incisor. Taurodontism was more prevalent in the maxillary first molar and in the mandibular first molar. Dilaceration was not clearly associated with a particular tooth. The classifications systems used in this review allowed for the better understanding and analysis of the many anatomical variations present in teeth. The variations in shape most found were dens invaginatus and radix entomolaris. The most frequently reported anatomical variation was in the number of canals.

Effectiveness of antimicrobial photodynamic therapy as an adjunct to mechanical instrumentation in reducing counts of Enterococcus faecalis and Candida albicans from C-shaped root canals

BACKGROUND/PURPOSE

The aim was to assess the effectiveness of antimicrobial photodynamic therapy (aPDT) as an adjunct to mechanical instrumentation (MI) in reducing Enterococcus faecalis (E faecalis) and Candida albicans (C albicans) counts from C-shaped root-canals.

METHODS

Teeth with C-shaped canals as identified on cone beam computed tomographic images were included. Following incubation with E faecalis and C albicans, samples were divided into 4 groups a four follows: Group-1: MI with adjunct aPDT; Group-2: aPDT alone; Group-3: MI alone; and Group-4: no treatment. The pulp chambers of these teeth were exposed and coronal pulp was mechanically derided using sterile endodontic excavators. Using flexible files, all canals were debrided up to size #30 K-files with intermittent irrigation with 2.5% sodium hypochlorite irrigation. In Groups 1 and 3, methylene-blue was injected in all canals and aPDT was performed using a 600 nm diode laser. Sample-size estimation was done on data from a pilot investigation and group-comparisons were done using one way analysis of variance and Bonferroni post-hoc adjustment tests. P < .05 was considered statistically significant.

RESULTS

Sixty periodontally hopeless mandibular second molars with C-shaped canals were included. There was a statistically significant reduction CFU/mL of E faecalis (P < .001) and C albicans (P < .001). At post-operative microbial assessments in Group-1. There was no difference CFU/mL of E faecalis and C albicans at post-operative microbial assessments in Groups 2-4.

CONCLUSION

MI with adjunct aPDT is more effective in reducing count of E faecalis and C albicans from C-shaped root canals.

Refined tooth and pulp segmentation using U-Net in CBCT image

OBJECTIVES

The aim of this study was extracting any single tooth from a CBCT scan and performing tooth and pulp cavity segmentation to visualize and to have knowledge of internal anatomy relationships before undertaking endodontic therapy.

METHODS

We propose a two-phase deep learning solution for accurate tooth and pulp cavity segmentation. First, the single tooth bounding box is extracted automatically for both single-rooted tooth (ST) and multirooted tooth (MT). It is achieved by using the Region Proposal Network (RPN) with Feature Pyramid Network (FPN) method from the perspective of panorama. Second, U-Net model is iteratively performed for refined tooth and pulp segmentation against two types of tooth ST and MT, respectively. In light of rough data and annotation problems for dental pulp, we design a loss function with a smoothness penalty in the network. Furthermore, the multi-view data enhancement is proposed to solve the small data challenge and morphology structural problems.

RESULTS

The experimental results show that the proposed method can obtain an average dice 95.7% for ST, 96.2% for MT and 88.6% for pulp of ST, 87.6% for pulp of MT.

CONCLUSIONS

This study proposed a two-phase deep learning solution for fast and accurately extracting any single tooth from a CBCT scan and performing accurate tooth and pulp cavity segmentation. The 3D reconstruction results can completely show the morphology of teeth and pulps, it also provides valuable data for further research and clinical practice.

Assessment of root morphology and canal configuration of maxillary premolars in a Saudi subpopulation: a cone-beam computed tomographic study

BACKGROUND

The objective of this study was to use CBCT to look into the root canal morphology of maxillary premolars in a Saudi Arabian subpopulation and associate the results to existing canal morphology classifications.

METHODS

The sample size for this analysis was 500 right and left untreated maxillary first and second premolars with fully formed roots from 250 Saudi residents (125 male and 125 female). The following observations were made using CBCT on the teeth related: (1) The number and morphology of roots; (2) The canal morphology for each root according to Vertucci's classification. The frequency and similarities between the right and left sides, as well as between females and males, were studied. The Chi-square test was used to assess the results.

RESULTS

Of the 500 maxillary first premolars studied, 199 teeth had one root (39.8%), whilst 293 (58.6%) were two-rooted. Three-rooted maxillary first premolars were found in 8 (1.6%). For maxillary second premolars, 416 premolars had one root (83.2%), whilst 79 (15.8%) had two roots and the rest 5 (1.0%) were three roots. There were significant differences of number of root were found between groups (p > 0.05). For maxillary first premolar, Type IV was the most frequent, accounting for 57.8% of the sample (n = 289), followed by type II (32.8%, n = 164). For maxillary second premolar, Type I was mainly occurrence 302 (60.4%), followed by Type II (16.4%, n = 82).

CONCLUSIONS

The majority of maxillary first premolars had two roots and two root canals, while one root and one root canal was the most common anatomical configuration for maxillary second premolars. Additional canal forms do occur on occasion, and clinicians should pay close attention to them.

Micro-CT evaluation of maxillary first molars: interorifice distances and internal anatomy of the mesiobuccal root

This study aimed to describe the morphometric relationship of root canal orifices on the pulp floor in the presence/absence of mesiobuccal second canal (MB2) in the maxillary first molars and other aspects of its internal anatomy. Sixty-two maxillary first molars were scanned by micro-CT. The presence of the MB2 canal was verified. The distance between the center points of the MB1, MB2, distobuccal (DB), and palatal (P) canal orifices on the pulp floor were measured (MB1-MB2, MB1-DB, MB2-DB, MB1-P, and DB-P). The MB1-P to DB-P ratio was calculated. The distances between the anatomic apex and the MB1 and MB2 apical foramina were measured. The length of the band-shaped isthmus was also measured. Student's t-test was applied to verify the association between the presence of an MB2 canal, the interorifice distances, and the ratio of the MB1-P to DB-P distance (α = 5%). The MB2 canal was present in 43 roots (69.35%). Statistics showed significant differences when MB2 was present for the largest MB1-P distance (p < 0.05) and higher values for the MB1-P to DB-P ratio (p < 0.05). A band-shaped isthmus was detected in 25.8% of MB roots. The mean distance from the apical foramen to the isthmus floor ranged from 1.74 for MB1 canals to 1.42 for MB2 canals. Canal orifice distances on the pulp floor may predict the presence of MB2 canals. There was a high incidence of isthmus, accessory canals, and apical delta in the critical apical zone in MB roots of maxillary first molars.

Application of a new system for classifying root and canal anatomy in studies involving micro-computed tomography and cone beam computed tomography: Explanation and elaboration

Adequate knowledge and accurate characterization of root and canal anatomy is an essential prerequisite for successful root canal treatment and endodontic surgery. Over the years, an ever-increasing body of knowledge related to root and canal anatomy of the human dentition has accumulated. To correct deficiencies in existing systems, a new coding system for classifying root and canal morphology, accessory canals and anomalies has been introduced. In recent years, micro-computed tomography (micro-CT) and cone beam computed tomography (CBCT) have been used extensively to study the details of root and canal anatomy in extracted teeth and within clinical settings. This review aims to discuss the application of the new coding system in studies using micro-CT and CBCT, provide a detailed guide for appropriate characterization of root and canal anatomy and to discuss several controversial issues that may appear as potential limitations for proper characterization of roots and canals.

Anatomical Evaluation of Mandibular Molars in a Saudi Population: An In Vivo Cone-Beam Computed Tomography Study

Objective

This study assessed the canal configuration of mandibular molars according to Vertucci's classification of a Saudi population using cone-beam computed tomography (CBCT).

Methods

A total of 290 first and 367 second mandibular molars were analyzed. The CBCT images were evaluated in three sections to inspect the number of roots and canals and canal system. The data are presented as frequencies and percentages. The chi-squared test was used to assess differences between both sides. SPSS was used for analysis, with a significance level of α ≤ 0.05.

Results

Among the first molars, 95.4% of the teeth had two roots, and 64.5% had three canals. Approximately 57.9% showed Vertucci type IV mesial roots. Between the second molars, 89.6% of teeth had two roots and 80.4% had three canals. The frequency of Vertucci type IV (39.4%) was the highest in mesial roots. The first molars showed a high prevalence of 3-rooted teeth (5.5%). Both the right and left sides showed teeth with similar external and internal anatomy (p < 0.05).

Conclusion

Most of the mandibular first and second molars had two roots and three canals. In the first mandibular molars, similar to the second mandibular molars, the majority of the mesial canals had Vertucci type IV, while the distal canals had Vertucci type I.

Root and Root Canal Morphology Classification Systems

Introduction

While there are many root morphology classification systems with their own distinct advantages, there are many shortcomings that come along with each system.

Objectives

The aim of this review was to compare the various root and root canal morphology classifications, their advantages, limitations, and clinical and research implications. Data Sources and Selection. An extensive literature search was conducted on PubMed and Scopus to identify the published data on root and root canal classification systems published until 1 May 2020 using keywords, root canal classification system, classification systems for root canals, and root morphology. The related literature was reviewed and then summarized. Data Synthesis. Several studies have analysed and detailed root and root canal classifications and further added new subsystems, works of Weine et al. (1969) and Vertucci et al. (1974). Besides, Sert and Bayirli (2004) added supplementary types to Vertucci's classification system. A new classification was most recently introduced by Ahmed et al. (2017) involving the use of codes for tooth numbering, number of roots, and canal configuration.

Conclusions

Weine et al. classified only single-rooted teeth, without considering multirooted teeth and complex configurations. Vertucci's classification included complex configurations, with Sert and Bayirli adding further complex supplemental types. Ahmed et al.'s classification simplifies classifying root and canal morphology while overcoming the limitations of several previous classification systems making it beneficial for implementation in dental schools.

Micro-tomographic characterization of the root and canal system morphology of mandibular first premolars in a Chilean population

This study aimed to analyze the root anatomy and root canal system morphology of mandibular first premolars in a Chilean population. 186 teeth were scanned using micro-computed tomography and reconstructed three-dimensionally. The root canal system morphology was classified using both Vertucci’s and Ahmed’s criteria. The radicular grooves were categorized using the ASUDAS system, and the presence of Tomes’ anomalous root was associated with Ahmed’s score. A single root canal was identified in 65.05% of teeth, being configuration type I according to Vertucci’s criteria and code ¹MP¹ according to Ahmed’s criteria. Radicular grooves were observed in 39.25% of teeth. The ASUDAS scores for radicular grooves were 60.75%, 13.98%, 12.36%, 10.22%, 2.15%, and 0.54%, from grade 0 to grade 5, respectively. The presence of Tomes’ anomalous root was identified only in teeth with multiple root canals, and it was more frequently associated with code ¹MP^1–2 of Ahmed’s criteria. The root canal system morphology of mandibular first premolars showed a wide range of anatomical variations in the Chilean population. Teeth with multiple root canals had a higher incidence of radicular grooves, which were closely related to more complex internal anatomy. Only teeth with multiple root canals presented Tomes’ anomalous root.

Taurodontism and C-shaped anatomy: is there an association?

OBJECTIVES

To evaluate the relation between taurodontism and C-shaped configuration, as well as the prevalence and classification according to sex, left/right position, and arc length in the mandibular premolar and molar teeth using cone beam computed tomography (CBCT).

METHODS

The presence of taurodontism and C-shaped configuration were evaluated using CBCT scans and classified by two independent radiologists. The sex, location in the jaw (left-right), and mandibular arc length measurements were recorded. The Chi-square test was used to determine the presence of taurodontism and C-shape configuration according to sex, left/right location, and independent-sample t tests were used to assess the relation between the arc length.

RESULTS

The prevalence of taurodontism was significantly higher in the female population, whereas the C-shaped configuration was more frequent in males (p < 0.05). In both sexes, the most common type was hypotaurodont (7.5%). In the molars, the prevalence was significantly higher in second molars, and the most common C-shaped configuration type was C3 (39.3%). The prevalence was significantly higher in the first premolar, with C2 (22.4%) being the most frequent type in the premolars (p < 0.05). The arc length and location in the jaw were not significantly affected (p > 0.05).

CONCLUSIONS

A high correlation was revealed between taurodontism and complicated C-shape canal configurations. Practitioners should be very careful about the presence of C-shape morphology in taurodontism treatment, and various types of C-shaped morphology ranging from coronal to the apical direction.

Monoradicular primary mandibular first molar: A rare case in Aseer Province of Saudi Arabia

Morphological variations can occur in primary and permanent teeth. Genetic and environmental factors could be responsible for various dental anomalies. Anomalous teeth are usually asymptomatic and are diagnosed during routine oral examination. These anomalies may increase caries susceptibility and complicate dental treatment procedures such as extraction or root canal treatment. We report a rare case of mandibular first molar with a single root and a root canal.

Application of a new system for classifying root canal morphology in undergraduate teaching and clinical practice: a national survey in Malaysia

AIM

To evaluate and compare the feedback of final year undergraduate dental students in eight Malaysian dental schools on the application of a new system for classifying root canal morphology in teaching and clinical practice.

METHODS

One PowerPoint presentation describing two classification systems for root canal morphology (Oral Surgery Oral Medicine Oral Pathology, 1974 38, 456 and its supplemental configurations, International Endodontic Journal 2017, 50, 761) was delivered to final year undergraduate dental students in eight dental schools in Malaysia by two presenters (each presented to four schools). To examine students' feedback on the utility of each system, printed questionnaires consisting of six questions (five multiple choice questions and one open-ended question) were distributed and collected after the lecture. The questionnaire was designed to compare the classification systems in terms of accuracy, practicability, understanding of root canal morphology and recommendation for use in pre-clinical and clinical courses. The exact test was used for statistical analysis, with the level of significance set at 0.05 (P = 0.05).

RESULTS

A total of 382 (out of 447) students participated giving a response rate of 86%. More than 90% of students reported that the new system was more accurate and more practical compared with the Vertucci system (P < 0.001). Overall, 97% of students reported the new system helped their understanding of root and canal morphology compared with the Vertucci classification (P < 0.001). Over 97% of students recommended the use of the new system in teaching, pre-clinical courses and clinical practice (P < 0.001). Except for two schools, no significant difference was detected between the responses of students for all questions at the different schools (P > 0.05). The students' responses for all questions were almost similar for both presenters (P > 0.05).

CONCLUSIONS

The new system of International Endodontic Journal 2017, 50, 761 for classifying root and canal morphology was favoured by final year undergraduate dental students in Malaysia. The new system has the potential to be included in the undergraduate endodontic curriculum for teaching courses related to root and canal morphology.

Root canal morphology of primary maxillary second molars: a micro-computed tomography analysis

AIM

Successful endodontic treatment of primary teeth requires comprehensive knowledge and understanding of root canal morphology. The purpose of this study was to investigate the root canal configurations of primary maxillary second molars using micro-computed tomography.

METHODS

Extracted human primary maxillary second molars (n = 57) were scanned using micro-computed tomography and reconstructed to produce three-dimensional models. Each root canal system was analysed qualitatively according to Vertucci's classification.

RESULTS

22.8% (n = 13) of the sample presented with the fusion of the disto-buccal and palatal roots; of these, Type V was the most prevalent classification. For teeth with three separate roots (n = 44), the most common root canal type was Type 1 for the palatal canal (100%) and disto-buccal canal (77.3%) and Type V for the mesio-buccal canal (36.4%). Overall, 7% (n = 4) of mesio-buccal canals were 'unclassifiable'.

CONCLUSION

The root canal systems of primary maxillary second molars were not only complex but had a range of configurations that may contribute to unfavourable clinical outcomes after endodontic treatment.

Palatogingival groove and root canal instrumentation

AIM

To evaluate the morphology and impact of root canal preparation in maxillary incisors with palatogingival grooves (PGG).

METHODOLOGY

Twenty extracted human maxillary incisors with PGG were subjected to macroscopic analysis and scanning electron microscopy analysis (SEM). The following characteristics of the PGG were evaluated: depth, point of origin in the cingulum, extension and position on the lingual surface. Furthermore, the presence of calculus, communications between the root canal system and the PGG, and root resorptions were investigated. The root canals were subsequently instrumented with K-files of three consecutive sizes. The teeth were sectioned, and the axial plane of each tooth section was imaged using SEM before and after instrumentation. The distance between the root canal walls and the PGG was calculated according to the location. Additionally, the distance between canal walls and cementum was measured at three different sites, to verify if instrumentation influenced dentine removal on a specific wall in teeth with PGG. Statistical analysis was performed using the Mann-Whitney or Student's t-test (P < 0.05).

RESULTS

Macroscopic analysis revealed that a deep groove was most frequently observed (75%), followed by a depression/shallow groove (25%) (P < 0.05). PGG typically originated in the distal margin ridge of the cingulum (65%) (P < 0.05), extending only to the middle (45%) or up to the apical (50%) third of the root (P < 0.05). Additionally, PGGs were typically located on the distal aspect of the lingual surface (70%) (P < 0.05). Calculus was concentrated on the surface of the crown and cementum-enamel junction (P < 0.05). Communication between the root canal and PGG was present in 35% of teeth, and root resorptions were noted in 50% of teeth. The distance between the external root surface and the pulp cavity was significantly narrower after instrumentation (P < 0.05); however, root canal preparation did not influence dentine removal on the specific wall associated with the groove (P > 0.05).

CONCLUSIONS

Palatogingival grooves were characteristically deep and originated from the distal margin of the cingulum. Although it has been associated with a thinner root wall, root canal preparation did not influence the thickness of the specific wall in the maxillary incisors with PGG.

Symmetry of root and root canal morphology of mandibular incisors: A cone-beam computed tomography study in vivo

Background

Aim of this study was to analyze the root canal configuration in mandibular central and lateral incisors in vivo using cone-beam computed tomography (CBCT) imaging.

Material and Methods

A total of 487 mandibular central incisors and 491 mandibular lateral incisors from 250 patients were examined using CBCT imaging, previously taken for diagnosis and treatment. The number of roots, root canal system configuration, presence of apical confluences, distance between confluences and radiographic root end, symmetry between left and right elements were recorded and statistically analyzed.

Results

All the examined teeth presented only one root. No significant differences were found between the prevalence of two root canals in mandibular central incisors (219 teeth, 45%) compared to lateral incisors (211 teeth, 43%).

Conclusions

The percentage of Vertucci type II configuration was higher than expected, being more frequent than type III. Type I was the prevalent, while other configurations were present but rare. Key words:Cone-beam computed tomography, mandibular incisors, root canal anatomy, confluences.

Periodontal Regenerative Treatment of Intrabony Defects Associated with Palatal Grooves: A Report of Two Cases

A palatal radicular groove (PRG) is a morphological deformity, occurring during tooth development. It is usually located on the palatal aspect of maxillary incisors and frequently associated with periodontal or endodontic-periodontal lesions. Some treatment options were described for such lesions, including primary endodontic treatment and periodontal surgery and extraction with intentional replantation after removal of a PRG and endodontic treatment. The present paper reported two cases of PRG-associated deep intrabony defects, successfully treated with periodontal surgery with enamel matrix derivative (EMD) application and mechanical removal of PRGs, avoiding endodontic treatment or retreatment. The complexity of the diagnostic process was also discussed.

Cone beam computed tomography in Endodontics - a review of the literature

The use of cone beam computed tomography (CBCT) in the diagnosis and/or management of endodontic problems is increasing and is reflected in the exponential rise in publications on this topic in the last two decades. The aim of this paper is to: (i) Review current literature on the endodontic applications of CBCT; (ii) Based on current evidence make recommendations for the use of CBCT in Endodontics; (iii) Highlight the areas in which more research is required.