CBCT Study of root and canal morphology of permanent mandibular incisors in a south Brazilian populationABSTRACT
Objective: The aim of this study was to investigate the root canal morphology of permanent mandibular incisors in a South Brazilian population using cone beam computed tomography.
Methods: A total of 520 cone beam computed tomography images of mandibular incisors from patients in Joinville, Brazil, were analyzed. The following parameters were assessed: tooth type, number of roots, gender, root canal configuration, and bilateral occurrence of a second canal. Root canal configurations were categorized according to Vertucci’s and Ahmed’s classification systems. Descriptive statistics were used to analyze the frequency of different root canal morphologies, while Fisher’s exact test was applied to evaluate gender-related differences in morphology (p<0.05).
Results: All permanent mandibular incisors (n=520) had a single root, with a second canal present in 35.2% of cases. The most prevalent canal configurations were Vertucci Type I and Ahmed 1II1 (64.5%), while Vertucci Type III and Ahmed 1II1-2-1 (29.05%) were the most common in incisors with two canals. No significant gender-based differences were found regarding the presence of a second canal or symmetry.
Conclusion: In the South Brazilian population evaluated, permanent mandibular incisors typically have a single root, with variations in canal number. No gender-related differences or symmetry patterns were observed. Mandibular incisors exhibit variations in their canal systems, which may affect the success of endodontic treatment. Therefore, professionals should carefully assess the internal anatomy of these teeth.
Indexing terms
Anatomy; Cone-beam computed tomography; Dental pulp cavity; Endodontics; Incisor
RESUMO
Objetivos: O objetivo deste estudo foi investigar a morfologia da raiz e dos canais radiculares dos incisivos permanentes inferiores em uma população do Sul do Brasil, utilizando a tomografia computadorizada de feixe cônico.
Métodos: Um total de 520 imagens de tomografia computadorizada de feixe cônico de incisivos mandibulares de pacientes de Joinville, Brasil, foram analisadas. Os seguintes parâmetros foram avaliados: dente, número de raízes, sexo, configuração do canal radicular e ocorrência bilateral de um segundo canal. As configurações dos canais radiculares foram categorizadas de acordo com as classificações de Vertucci e Ahmed. Estatísticas descritivas foram utilizadas para analisar a frequência das diferentes morfologias dos canais radiculares, enquanto o teste exato de Fisher foi aplicado para avaliar diferenças relacionadas ao sexo na morfologia (p< 0 , 05 ).
Resultados: Todos os incisivos mandibulares permanentes (n=520) apresentaram uma única raiz, com a presença de um segundo canal em 35,2% dos casos. As configurações de canal mais prevalentes foram Vertucci Tipo I e Ahmed 1 II 1 (64,5%), enquanto Vertucci Tipo III e Ahmed 1 II 1 - 2 - 1 (29,05%) foram as mais comuns nos incisivos com dois canais. Não foram encontradas diferenças significativas entre os gêneros quanto à presença de um segundo canal ou simetria.
Conclusão: Na população do Sul do Brasil avaliada, os incisivos mandibulares permanentes geralmente possuem uma única raiz, com variações no número de canais. Não foram observadas diferenças relacionadas ao gênero nem padrões de simetria. Os incisivos mandibulares apresentam variações em seus sistemas de canais, o que pode afetar o sucesso do tratamento endodôntico. Portanto, os profissionais devem avaliar cuidadosamente a anatomia interna desses dentes.
Termos de indexação
Anatomia; Tomografia computadorizada de feixe cônico; Cavidade pulpar; Endodontia; Incisivo
INTRODUCTION
To reduce endodontic failures caused by incomplete debridement and obturation, a thorough understanding of root canal anatomy and its morphological variations is essential [1,2]. Inaccurate diagnosis of the root canal anatomy may lead to a significant failure rate of endodontic treatment [3]. Untreated root canals correspond to an incidence of 12.2% and 17.4% in cases of periapical lesions in mandibular central and lateral incisors, comprising one of the primary etiological factors for failures in endodontic therapy [4].
Ordinarily, teeth with single roots exhibit solitary canals [3]. Nevertheless, mandibular incisors are well-known for showcasing variations in the root canal morphology [5], predominantly due to secondary (bifurcated) canals, lateral canals, and apical deltas. This characteristic can pose challenges to achieving satisfactory canal preparation [6]. During endodontic treatment, residual microorganisms may persist in these regions, leading to periapical lesions, abscess formation, persistent pain, and compromising the overall prognosis of the endodontic treatment. Thus, thorough knowledge of the root canal system will help to reduce endodontic failures caused by incomplete debridement and obturation [7-9].
Martins et al. [10] conducted a multicentric cross-sectional study with meta-analysis, examining a sample of 26,400 mandibular incisors. The results highlighted a variation in the frequency of the second canal in mandibular central and lateral incisors, ranging from 2.3% to 45.3%, and from 2.3% to 55.0%, respectively. This discrepancy has been primarily attributed to methodological and ethnic differences [11]. Different methodologies are outlined in the literature for investigating the internal anatomy of root canals, including decalcification [5], sectioning [12], two-dimensional radiographs [13], three-dimensional microtomography (Micro-CT) and three-dimensional Cone Beam Computed Tomography (CBCT) [14].
The CBCT is a diagnostic imaging examination, and due to its high resolution and noninvasive nature, it is employed as an auxiliary method in determining root and canal system morphology. It can detect complex variations in root canal anatomy and is superior to other methods, such as conventional and digital periapical radiography [13]. The CBCT image is also considered a reliable in vivo and ex-vivo approach for evaluating root canal anatomy [14,15].
Different classifications have been proposed to define the types of root canal morphology. The widely used is Vertucci’s classification [10,11,16-18]. Vertucci [8] classified the root canal configurations of human permanent teeth into eight types based on examining decalcified teeth. The decalcified teeth technique provides a three-dimensional view of the pulp cavity and root canal system. Technological advancements have enabled the study of endodontic characteristics with greater precision through micro-CT [19] and CBCT [20]. In light of this, Ahmed et al. [21] devised a straightforward, accurate, and practical coding system for describing root and canal configurations, with the potential for universal adoption [22].
Recognizing the importance of acquiring accurate knowledge about the anatomy and number of canals in mandibular incisors, and aiming to enhance the success rate of endodontic treatments while minimizing procedural errors, this study aims to evaluate and classify the root canal morphology of mandibular incisors in South Brazilian population using cone-beam computed tomography. The classification of root canal morphology was performed using two well-established systems: (1) Vertucci’s classification [5], which describes eight distinct root canal configurations based on decalcified teeth analysis, and (2) Ahmed’s classification [21], a systematic and universally applicable coding system for root and canal configurations. By applying these classifications, this study seeks to provide a comprehensive understanding of the anatomical variations of mandibular incisors, contributing to improved diagnostic accuracy and clinical decision-making in endodontic procedures.
METHODS
This study was approved by the ethics committee of the Universidade da Região de Joinville (Univille, University of the Joinville Region) (Joinville, SC, Brazil) (protocol n. 67080122.6.0000.5366) and carried out following the Helsinki Declaration on medical protocols and ethics.
Study design and sample size calculation
This retrospective cross-sectional study used CBCT scans from a private dental radiology clinic in South Brazil (Joinville, Santa Catarina, Brazil). The research was conducted between August 2022 and April 2023, and the images were obtained between 2020 and 2023. The study sample consisted of 130 CBCT scans (520 permanent mandibular incisors). The patients included in the study sample had not been subjected to additional radiation for the present investigation. The sample size calculation was expressed as n = Z2 * P(1 - P)/d2, where Z represents the statistical value for a confidence level of 85%, P represents the expected prevalence of 23.95%, and the value of d (precision) is set at 5%, according to Pourhoseingholi et al. [23].
The imaging was conducted using Orthopantomographtm OP300 Maxio (Helsinki, Finland) following the protocol: FOV = 470 x 470 mm, tube peak potential = 90 kVp, tube current = 10 mA, exposure time = 6.1 s, voxel size = 0.085 mm.
Inclusion criteria
The inclusion criteria were as follows: good-quality CBCT scans, absence of artifacts or distortions, Field Of View (FOV) including the mandibular incisors, and permanent mandibular incisors with complete root formation.
Exclusion criteria
CBCT scans with low or poor resolution, the presence of root resorption, prior endodontic treatment, mandibular or dental anomalies, and periradicular lesions were excluded.
Data analysis
After training and calibration by a senior oral and maxillofacial radiologist, one examiner performed the analysis. 50 CBCT scans were used for the concordance assessment. The examiner evaluated the 50 CBCT scans twice at an interval of 2 weeks. Inter-observer and intra-observer (0.75) concordance were assessed by Cohen’s Kappa, with an excellent agreement. The examiner manipulated the images to improve the contrast and brightness to access the images with more precision by using InVesalius, a free-source software (Invesalius, version 2.0, Campinas, SP, Brazil).
Each selected tooth was recorded with the following information: patient gender, tooth number, number of roots, presence of the second canal, and canal configuration according to Vertucci [5] and Ahmed’s [21] classification. Descriptive statistics was used to measure the frequency morphology of mandibular incisors according to each classification. Fisher’s exact test compared sex-associated differences in mandibular incisor morphology. Data extraction was performed using Microsoft Excel software. Analyses were performed with Stata/SE v.14.1 software (StataCorp LP, USA). The significance level was determined as p<0.05.
RESULTS
All permanent mandibular incisors (n=520) presented a single root. Figure 1 illustrates representative CBCT images and schematic illustrations of the five root canal configuration variants observed in permanent mandibular incisors, classified according to the systems proposed by Vertucci and Ahmed. 35.2% of the sample had a second canal, which was classified into four variants of root canal morphology according to Vertucci’s [5] and Ahmed’s [21] classifications. Table 1 shows the frequency morphology of mandibular incisors according to Vertucci [5] and Ahmed’s [21] classification. Vertucci Type I/1II1 (64.8%) was the prevalent configuration, followed by Type III/1II1-2-1 (29.05%), Type II/1II2-1 (4.22%), Type V/1II1-2 (1.35%) and Type IV/1II2 (0.58%).
CBCT images and illustrations of the five anatomical variants in permanent mandibular incisors according to Vertucci [<xref>8</xref>] and Ahmed et al. [<xref>21</xref>].
Frequency morphology of mandibular incisors according to Vertucci [<xref>5</xref>] and Ahmed's [<xref>21</xref>] classification.
Upon comparing central and lateral incisors, a statistically significant difference was identified in the presence of the second root canal. Mandibular lateral incisors demonstrate a higher incidence of a second canal (p<0.05) (table 2). No significant difference was found between genders regarding the distributions of the presence of a second canal (table 3). All p-values were more significant than 0.05.
Bilateral incidence of two root canals was observed in 8.5% (n=11) of central incisors and 23.1% (n=30) of lateral incisors. The bilateral pattern was categorized based on gender, where no statistically significant differences were found in the examined groups (table 4).
DISCUSSION
The effectiveness of endodontic treatment relies on properly shaping and cleaning the root canal, followed by its effective obturation. Several studies indicate that the root canal system exhibits remarkable complexity, with multiple documented variations. Therefore, the lack of understanding of this system represents one of the primary causes of failure in endodontic procedures [5].
This retrospective study aimed to examine the complex anatomy of the root canals of mandibular incisors through CBCT. All incisors assessed in this study exhibited a single root, consistent with studies by Karobari et al. [11], Baxter et al. [18], and Martins et al. [24]. However, some studies found 0.3% of the sample showed the presence of two roots [25].
The anatomy of the root canals in mandibular incisors displays numerous variations in its system, which were categorized according to the classifications of Vertucci and Ahmed. In the current study, it was observed that Vertucci Type I and Ahmed’s configuration (1II1) were the most frequent configurations in mandibular incisors (64.8%), consistent with the findings of Lin et al. [26].
Regarding the presence of two canals, the most frequent configuration was Type III / 1II1-2-1, in agreement with studies conducted by Karobari et al. [11], Candeiro et al. [17], Villa et al. [22], Martins et al. [24] and Saati et al. [27]. In contrast to the results presented by Baxter et al. [18], who identified Type II / 1II2-1 as the second most prevalent configuration, with the absence of Type III / 1II2-1 configuration in any incisor of the sample. The other types (Type VI / 1II2-1-2, Type VII / 1II1-2-1-2, Type VIII / 1II3-3) showed low percentages or nonexistent.
The results of this study also indicate a significantly higher incidence of the second canal in the mandibular lateral incisors compared to the central incisors, aligning with the findings of studies by Zhengyan et al. [25] and Saati et al. [27].
No significant gender differences were observed in the distributions regarding the presence of the second canal. However, our study indicated that males exhibit a slightly higher incidence compared to females, consistent with studies by Karobari et al. [11] and Martins et al. [14]. As no statistically relevant differences were identified, both sexes should be treated similarly in a clinical setting.
The knowledge of the existence of anatomical symmetry of the root canal is of great value during clinical practice. However, the bilateral presence of two root canals was identified in 8.5% of central incisors and 23.1% of lateral incisors. Therefore, the prevalence of symmetry regarding the number and configuration of the root canal for incisors with two root canals did not yield statistically significant results. Thus, the internal anatomy of a mandibular incisor cannot be accurately predicted from the root canal anatomy of the contralateral tooth, as the prevalence of symmetry did not reach statistical significance. Individual clinical assessment and imaging examinations remain necessary.
This study revealed that 35.2% of roots presented two canals. The variation in the prevalence of two canals in mandibular incisors can be attributed to different canal identification techniques (radiographic examination, sectioning, decalcification and coloring), study designs (in vivo versus ex vivo), sample sizes, and ancestry. In previous studies conducted in South America, specifically in Brazil [17], higher frequencies of the second canal in mandibular incisors were reported compared to studies in China, where prevalence data of the second canal were published with documented percentages of 6.7% [28] and 8.9% [29]. On the other hand, the prevalence of the second canal in European and Middle Eastern countries showed results of 45.0% [30], 27.4% [14], and 40.5% [31] for Italy, Portugal, and Israel, respectively.
Anthropological data can provide insights into the reasons for the observed differences between geographic regions and ethnic groups discussed earlier. The human species can be traced back to a region in Central Africa near Nairobi, Kenya, where it spread to colonize the world. The migratory routes taken by early humans can help explain the origin of ethnic groups and their differences. It is believed that early humans dispersed through two main migratory routes. These two main migratory routes gave rise to three major ethnic groups in the early stages of humanity: Africans, who remained in Africa; Caucasians, who migrated to Europe; and Asians, who migrated to East Asia [10]. Considering the migratory routes and the formation of the three major ethnic groups, it can be hypothesized that the higher prevalence of a second canal in mandibular incisors in Caucasians may have arisen through genetic mutation and/or adaptation to the local environment during the migratory process towards Europe [10].
Few studies have directly compared the Vertucci classification system [5] with the system by Ahmed et al. [21], with one such study conducted in Brazil [11]. Therefore, this study contributes to the currently limited information for comparing the two systems. The present study suggests that both classification systems help categorize permanent anterior teeth. However, additional studies involving more complex tooth types (maxillary and mandibular molars) are needed to compare the two classification systems further [16]. Although all mandibular incisors evaluated in this study exhibited single roots, Ahmed et al.’s classification [21] allows for describing dental anomalies, such as the presence of two roots, which is an advantage of this system compared to the Vertucci classification [5].
The classification system proposed by Ahmed et al. [21] provides comprehensive information (e.g., tooth number, number of roots, root canal configuration) in a single code that accurately represents tooth anatomy. The primary aim of the classification was to create an easily applicable, precise, and user-friendly classification of root canal morphology for professionals and researchers. Furthermore, a thorough understanding of root canal morphology, with a comprehensive grasp of the complexity of the root canal system, is particularly crucial in clinical practice to achieve desired treatment outcomes, as well as for documentation and communication among professionals.
A survey conducted with final-year dental students revealed that over 90% of the students believed that the classification system proposed by Ahmed et al. [21] is more accurate and practical than the Vertucci classification [5]. It allows for the description of configuration types without the need to memorize them in Roman numerals.
The complexity of root canal system morphology has propelled the development of various technologies to enhance endodontic treatment effectiveness. Among these innovations, notable advancements include improvements in nickel-titanium (NiTi) rotary and reciprocating files, the use of ultrasonic equipment to enhance disinfection, and the adoption of various obturation techniques, such as continuous wave obturation and hydraulic obturation. The latter involves the use of single cones and silicate-based hydraulic cement [19].
The imaging acquisition techniques have also undergone significant technological advancements [32]. CBCT imaging has been considered the most reliable approach in vivo for examining root canal anatomy. This method allows addressing, at a relatively low cost, the influence of various epidemiological factors on the morphology of the root canal system using significant subpopulations in different geographic regions [10]. Understanding to what extent these factors can influence the proportion of additional root canals in a specific group of teeth can help clinicians anticipate the presence of more complex morphologies in clinical practice. Micro-CT is also an important tool for evaluating root canal morphology due to its high resolution and non-destructive nature. However, its application in clinical practice is limited due to high radiation exposure [19]. Thus, CBCT emerges as an alternative for assessing root canals. Future investigations comparing CBCT and micro-CT may uncover variations in the accuracy of the methodologies.
CONCLUSION
In the South Brazilian population evaluated, the Vertucci Type 1 classification and code 1II1 (64.5%) were mandibular incisors’ most prevalent canal configuration. The Vertucci Type III / 1II1-2-1 classification was the most frequently observed canal configuration in incisors with two canals. There was no significant difference in the distribution between genders regarding the presence of the second canal or symmetry.
Acknowledgments
Research and Innovation Support Foundation of Santa Catarina State (Fundação de Amparo à Pesquisa e Inovação do Estado de Santa Catarina – FAPESC), Public Call for Proposals No. 19/2024 and Coordination for the Improvement of Higher Education Personnel (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – CAPES), Public Call for Proposals No. 04/2025.
-
Article aligned with the Good Health and well-being goal of the Sustainable Development Goals (SDGs).
-
Article based on the dissertation by AMYC VALENZA, entitled “Avaliação da Configuração do Canal Radicular de Incisivos Inferiores com Tomografia Computadorizada de Feixe Cônico em Joinville/SC”. Universidade da Região de Joinville; 2023.
-
How to cite this article
Valenza AMYC, Abuabara A, Nascimento TVPM, Roskamp L, Miranda de Araujo C, Baratto-Filho F. CBCT Study of root and canal morphology of permanent mandibular incisors in a south Brazilian population. RGO, Rev Gaúch Odontol. 2026;74:e20260021. http://dx.doi.org/10.1590/1981-86372026002120250048
Data Availability
The research data are available from the corresponding author upon reasonable request.
REFERENCES
-
1 Versiani MA, Pécora JD, de Sousa-Neto MD. Root and root canal morphology of four-rooted maxillary second molars: a micro-computed tomography study. J Endod. 2012;38(7):977-82. doi: http://doi.org/10.1016/j.joen.2012.03.026
» https://doi.org/10.1016/j.joen.2012.03.026 -
2 Mohammadi Z, Jafarzadeh H, Shalavi S, Bandi S, Patil S. Root and root canal morphology of human third molar teeth. J Contemp Dent Pract. 2015;16(4):310-3. doi: http://doi.org/10.5005/jp-journals-10024-1681
» https://doi.org/10.5005/jp-journals-10024-1681 -
3 Alobaid MA, Alshahrani EM, Alshehri EM, Shaiban AS, Haralur SB, Chaturvedi S, et al. Radiographic assessment of root canal morphology of mandibular central incisors using new classification system: a cross-sectional study. Medicine (Baltimore). 2022;101(37):e30751. doi: http://doi.org/10.1097/MD.0000000000030751
» https://doi.org/10.1097/MD.0000000000030751 -
4 Kayaoglu G, Peker I, Gumusok M, Sarikir C, Kayadugun A, Ucok O. Root and canal symmetry in the mandibular anterior teeth of patients attending a dental clinic: CBCT study. Braz Oral Res. 2015;29(1):1-7. doi: http://doi.org/10.1590/1807-3107BOR-2015.vol29.0090
» https://doi.org/10.1590/1807-3107BOR-2015.vol29.0090 -
5 Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol. 1984;58(5):589-99. doi: http://doi.org/10.1016/0030-4220(84)90085-9
» https://doi.org/10.1016/0030-4220(84)90085-9 -
6 Carrotte P. Endodontics: part 4. Morphology of the root canal system. Br Dent J. 2004;197(7):379-83. doi: http://doi.org/10.1038/sj.bdj.4811711
» https://doi.org/10.1038/sj.bdj.4811711 -
7 Leoni GB, Versiani MA, Pécora JD, Damião de Sousa-Neto M. Micro-computed tomographic analysis of the root canal morphology of mandibular incisors. J Endod. 2014;40(5):710-6. doi: http://doi.org/10.1016/j.joen.2013.09.003
» https://doi.org/10.1016/j.joen.2013.09.003 -
8 Vertucci FJ. Root canal anatomy of the mandibular anterior teeth. J Am Dent Assoc. 1974;89(2):369-71. doi: http://doi.org/10.14219/jada.archive.1974.0391
» https://doi.org/10.14219/jada.archive.1974.0391 -
9 Patel S, Patel P. Endodontic management of maxillary second molar with two palatal roots: a report of two cases. Case Rep Dent. 2012;2012:590406. doi: http://doi.org/10.1155/2012/590406
» https://doi.org/10.1155/2012/590406 -
10 Martins JNR, Worldwide Anatomy Research Group, Versiani MA. Worldwide Prevalence of the Lingual Canal in Mandibular Incisors: a multicenter cross-sectional study with meta-analysis. J Endod. 2023;49(7):819-35. doi: http://doi.org/10.1016/j.joen.2023.05.012
» https://doi.org/10.1016/j.joen.2023.05.012 -
11 Karobari MI, Noorani TY, Halim MS, Ahmed HMA. Root and canal morphology of the anterior permanent dentition in Malaysian population using two classification systems: a CBCT clinical study. Aust Endod J. 2021;47(2):202-16. doi: http://doi.org/10.1111/aej.12454
» https://doi.org/10.1111/aej.12454 -
12 Weine FS, Healey HJ, Gerstein H, Evanson L. Canal configuration in the mesiobuccal root of the maxillary first molar and its endodontic significance. Oral Surg Oral Med Oral Pathol. 1969;28(3):419-25. doi: http://doi.org/10.1016/0030-4220(69)90237-0
» https://doi.org/10.1016/0030-4220(69)90237-0 -
13 Neelakantan P, Subbarao C, Subbarao CV. Comparative evaluation of modified canal staining and clearing technique, cone-beam computed tomography, peripheral quantitative computed tomography, spiral computed tomography, and plain and contrast medium-enhanced digital radiography in studying root canal morphology. J Endod. 2010;36(9):1547-51. doi: http://doi.org/10.1016/j.joen.2010.05.008
» https://doi.org/10.1016/j.joen.2010.05.008 -
14 Martins JNR, Marques D, Leal Silva EJN, Caramês J, Mata A, Versiani MA. Influence of demographic factors on the prevalence of a second root canal in mandibular anterior teeth: a systematic review and meta-analysis of cross-sectional studies using cone beam computed tomography. Arch Oral Biol. 2020;116:104749. doi: http://doi.org/10.1016/j.archoralbio.2020.104749
» https://doi.org/10.1016/j.archoralbio.2020.104749 -
15 Borges CC, Estrela C, Decurcio DA, Pécora JD, Sousa-Neto MD, Rossi-Fedele G. Cone-beam and micro-computed tomography for the assessment of root canal morphology: a systematic review. Braz Oral Res. 2020;34:e056. doi: http://doi.org/10.1590/1807-3107bor-2020.vol34.0056
» https://doi.org/10.1590/1807-3107bor-2020.vol34.0056 -
16 Buchanan GD, Gamieldien MY, Tredoux S, Vally ZI. Root and canal configurations of maxillary premolars in a South African subpopulation using cone beam computed tomography and two classification systems. J Oral Sci. 2020;62(1):93-7. doi: http://doi.org/10.2334/josnusd.19-0160
» https://doi.org/10.2334/josnusd.19-0160 -
17 Candeiro GTM, Monteiro Dodt Teixeira IM, Olimpio Barbosa DA, Vivacqua-Gomes N, Alves FRF. Vertucci’s root canal configuration of 14,413 mandibular anterior teeth in a Brazilian population: a prevalence study using cone-beam computed tomography. J Endod. 2021;47(3):404-8. doi: http://doi.org/10.1016/j.joen.2020.12.001
» https://doi.org/10.1016/j.joen.2020.12.001 -
18 Baxter S, Jablonski M, Hülsmann M. Cone-beam-computed-tomography of the symmetry of root canal anatomy in mandibular incisors. J Oral Sci. 2020;62(2):180-3. doi: http://doi.org/10.2334/josnusd.19-0113
» https://doi.org/10.2334/josnusd.19-0113 -
19 Filipo-Perez C, Bramante CM, Villas-Boas MH, Húngaro Duarte MA, Versiani MA, Ordinola-Zapata R. Micro-computed tomographic analysis of the root canal morphology of the distal root of mandibular first molar. J Endod. 2015;41(2):231-6. doi: http://doi.org/10.1016/j.joen.2014.09.024
» https://doi.org/10.1016/j.joen.2014.09.024 -
20 Baratto Filho F, Zaitter S, Haragushiku GA, de Campos EA, Abuabara A, Correr GM. Analysis of the internal anatomy of maxillary first molars by using different methods. J Endod. 2009;35(3):337-42. doi: http://doi.org/10.1016/j.joen.2008.11.022
» https://doi.org/10.1016/j.joen.2008.11.022 -
21 Ahmed HMA, Versiani MA, De-Deus G, Dummer PMH. A new system for classifying root and root canal morphology. Int Endod J. 2017;50(8):761-770. doi: http://doi.org/10.1111/iej.12685. Erratum in: Int Endod J. 2018;51(10):1184.
» https://doi.org/10.1111/iej.12685 -
22 Villa N, Weissheimer T, Vier-Pelisser FV, Alcalde MP, Vivan RR, Duarte MAH, et al. Comparative study of Vertucci and Ahmed classifications to evaluate the main root canal configuration of mandibular incisors in a Brazilian population. Aust Endod J. 2022;48(3):409-14. doi: http://doi.org/10.1111/aej.12576
» https://doi.org/10.1111/aej.12576 - 23 Pourhoseingholi MA, Vahedi M, Rahimzadeh M. Sample size calculation in medical studies. Gastroenterol Hepatol Bed Bench. 2013;6(1):14-7
-
24 Martins JNR, Gu Y, Marques D, Francisco H, Caramês J. Differences on the root and root canal morphologies between Asian and white ethnic groups analyzed by cone-beam computed tomography. J Endod. 2018;44(7):1096-104. doi: http://doi.org/10.1016/j.joen.2018.04.001
» https://doi.org/10.1016/j.joen.2018.04.001 -
25 Zhengyan Y, Keke L, Fei W, Yueheng L, Zhi Z. Cone-beam computed tomography study of the root and canal morphology of mandibular permanent anterior teeth in a Chongqing population. Ther Clin Risk Manag. 2015;12:19-25. doi: http://doi.org/10.2147/TCRM.S95657. Erratum in: Ther Clin Risk Manag. 2016;12:387
» https://doi.org/10.2147/TCRM.S95657 -
26 Lin Z, Hu Q, Wang T, Ge J, Liu S, Zhu M, et al. Use of CBCT to investigate the root canal morphology of mandibular incisors. Surg Radiol Anat. 2014;36(9):877-82. doi: http://doi.org/10.1007/s00276-014-1267-9
» https://doi.org/10.1007/s00276-014-1267-9 -
27 Saati S, Shokri A, Foroozandeh M, Poorolajal J, Mosleh N. Root morphology and number of canals in mandibular central and lateral incisors using cone beam computed tomography. Braz Dent J. 2018;29(3):239-44. doi: http://doi.org/10.1590/0103-6440201801925
» https://doi.org/10.1590/0103-6440201801925 - 28 Zhao Y, Dong YT, Wang XY, Wang ZH, Li G, Liu MQ, et al. Cone-beam computed tomography analysis of root canal configuration of 4674 mandibular anterior teeth. Beijing Da Xue Xue Bao Yi Xue Ban. 2014;46(1):95-9.
-
29 Liu J, Luo J, Dou L, Yang D. CBCT study of root and canal morphology of permanent mandibular incisors in a Chinese population. Acta Odontol Scand. 2014;72(1):26-30. doi: http://doi.org/10.3109/00016357.2013.775337
» https://doi.org/10.3109/00016357.2013.775337 -
30 Valenti-Obino F, Di Nardo D, Quero L, Miccoli G, Gambarini G, Testarelli L, et al. Symmetry of root and root canal morphology of mandibular incisors: a cone-beam computed tomography study in vivo. J Clin Exp Dent. 2019;11(6):e527-e33. doi: http://doi.org/10.4317/jced.55629
» https://doi.org/10.4317/jced.55629 - 31 Shemesh A, Kavalerchik E, Levin A, Ben Itzhak J, Levinson O, Lvovsky A, et al. Root canal morphology evaluation of central and lateral mandibular incisors using cone-beam computed tomography in an Israeli population. J Endod. 2017;44(1):51-5
-
32 Patel S, Durack C, Abella F, Shemesh H, Roig M, Lemberg K. Cone beam computed tomography in endodontics: a review. Int Endod J. 2015;48(1):3-15. doi: http://doi.org/10.1111/iej.12270
» https://doi.org/10.1111/iej.12270
Edited by
-
Assistant editor
Luciana Butini Oliveira
