
==== Front
BMC Oral Health
BMC Oral Health
BMC Oral Health
1472-6831
BioMed Central London

39261832
4851
10.1186/s12903-024-04851-0
Research
Cone beam computed tomography analysis of the root and canal morphology of the maxillary second molars in a Syrian subpopulation
Allawi Safaa 1
Al-Tayyan Mouhammad 1
Achour Hassan 1
Al-Toutangy Eyad 2
Alsayed Tolibah Yasser Yasseralsayedtolibah@gmail.com

3
1 https://ror.org/03m098d13 grid.8192.2 0000 0001 2353 3326 Department of Operative and Endodontic Dentistry, Faculty of Dentistry, Damascus University, Damascus, Syria
2 Department of Orthodontics, National Dental Centre for Syrian Board and Specializations, Damascus, Syria
3 https://ror.org/03m098d13 grid.8192.2 0000 0001 2353 3326 Department of Pediatric Dentistry, Faculty of Dentistry, Damascus University, Damascus, Syria
11 9 2024
11 9 2024
2024
24 107123 5 2024
2 9 2024
© The Author(s) 2024
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ Open Access This article is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License, which permits any non-commercial use, sharing, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if you modified the licensed material. You do not have permission under this licence to share adapted material derived from this article or parts of it. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by-nc-nd/4.0/.
Aim

To investigate the root number and morphology of the maxillary second molars in the Syrian population besides bilateral symmetry, and the effect of gender.

Methods

250 Cone Beam Computed Tomography (CBCT) images (140 females, 110 males) were examined by two endodontists. The detailed analysis included the number of roots, the number of canals and their configurations, bilateral symmetry, and relation to gender. The evaluation was made according to Vertucci classification by analyzing the CBCT images at all levels (Axial, Coronal, Sagittal, Oblique, and 3D). The Chi-square statistical analysis was performed to compare the canals’ morphologies and bilateral symmetry in both genders via SPSS.

Result

The most common shape of the upper second molars is three roots (90.4%). There were significant differences between males and females regarding the symmetry of the number of roots (P < 0.05). The root canal configuration was mainly Vertucci type I classification in the Distobuccally (93.4%) and palatal root (99.6%). The most common type in the mesial root was type I (29.5%), showing all varieties of Vertucci classifications (except VII, and VIII) percentage of MB2 of 70.5%. The ratio of symmetry was (59.6%) with no significant statistical difference between the genders (P = 0.708).

Conclusion

Most maxillary second molars in the examined Syrian population were types (II) (associated with MB2 cases with three roots and four canals). In terms of symmetry, the number of roots surpassed the canal configuration. Males had a greater symmetrical tendency in the number of roots than females.

Keywords

Cone beam computed tomography
Maxillary second molars morphology
Vertucci classification
Syrian subpopulation
issue-copyright-statement© BioMed Central Ltd., part of Springer Nature 2024
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pmcIntroduction

Maxillary Second molars have a higher percentage of anatomical abnormalities than the first molar [1, 2]. Thus, these structural complexities result in a higher incidence of anatomical abnormalities when compared to first molars. These structural complexities complicate canal treatment, requiring a thorough and detailed understanding of the number of roots and canals involved [3]. Hence, the great importance of radiography can lead to making the best diagnosis and investigating the root number and the root canal morphology. Failure to diagnose these variations is usually due to the superimposition of anatomic structures. Thus, radiographs should be taken at different angles to detect and locate extra roots or canals to increase the success rates [4].

Permanent maxillary second molars often have three roots, one palatal and two buccal. These roots tend to come into proximity and may fuse to form two or one roots [5–7]. The mesial root often contains two canals, whereas a single canal is typically found in the distobuccal and palatal roots [5].

Various methods of evaluating the anatomy of the root canal system have been performed throughout history. Although staining is the gold standard [8], other methods are more commonly used, like conventional and digital radiography [9], computed tomography (CT), cone-beam computed tomography (CBCT) [10], and micro-computed tomography (micro-CT) [11], which is recently developed to provide high-quality information with high-micrometer-resolution images for extra-fine anatomic details. However, it is specified on extracted teeth [6]. The CBCT technique can be used in vivo without tooth loss and bilateral comparison for the same patient. The potential of visualizing the third dimension and eliminating anatomical overlays with a lower radiation dose than a computed tomography (CT) scan provides a better comprehension of the morphology in root canal systems [7].

Few studies have examined the maxillary second molar bilateral symmetry in the same individuals. This information is valuable for dentists as it allows them to predict the presence of additional roots or canals when treating a patient who has already undergone treatment for a second molar on the opposite side [12]. Therefore, this study aimed to investigate the number of roots, root canal morphology of the upper second molar, and bilateral symmetry in the Syrian subpopulation using CBCT. Besides, it explored the effects of gender on these morphological aspects. The first null hypothesis assumes that gender has no effect on the anatomical structure of the second molars. The second null hypothesis posits that anatomical symmetry in the maxillary second molars among the residents of Damascus, regardless of gender.

Materials and methods

The Research Ethics Committee of the Faculty of Dentistry, Damascus University, Syria (No: 3238) granted ethical approval for this study. The data included 766 CBCT images from the orthodontic department records at Damascus University Faculty of Dentistry from November 2020 to January 2022. The images were taken following AAOMA standards and guidelines to determine the presence of impacted canines for orthodontic assessment or surgical extraction of the impacted molar and its proximity to anatomical landmarks as a primary purpose.

Drawing from the findings of a precedent investigation of similar studies [13], the sample size for this current study was determined utilizing G* Power 3.1.9.4 (Heinrich-Heine-Universität, Düsseldorf, Germany). In the X2 analysis, sample sizes of 500 molars were derived from an effect size (w) of 0.17 (which was calculated based on the variation in anatomical symmetry between males and females in a sample of the Qatari population), the maximum and 85% power at a significance level of 0.05.

Criteria for inclusion specified fully erupted maxillary second molars on both right and left sides, possessing complete roots with a closed apex. Excluded images involved maxillary second molars cases with root resorption (internal or external), apical lesions, post and core restorations, calcified canals, previous endodontic treatment, or teeth with dental malformations. As a result, the selection criteria led to the inclusion of 250 CBCT images, comprising 500 maxillary second molars from patients aged 15 to 65 years.

Two experienced endodontists performed image evaluation and data analysis by examining the images in all directions roots and canals were investigated across various levels (axial, coronal, sagittal, oblique, and 3D) and orientation from the pulpal chamber towards the root apex and from mesial to distal employing settings like Brightness, density, contrast, invert, and sharpness filters, with a slice thickness of 0.25 mm for optimal visibility. The readings of the two endodontists were completely consistent and there was no difference between them. Subsequently, a third dental specialist researcher randomly reviewed 10% of the sample. The results from this third evaluation concurred with the initial one, as confirmed by Cohen’s κ test (K = 0.990, p ≤ 0.001).

CBCT images were captured using the SCANORA™ 3D 2013 (Soredex) device. Imaging was for the entire maxillofacial region with parameters including a scanning field dimension (FOV) of 145 × 130 mm, 15 MA intensity, 85 KV voltage, 0.2 mm voxel size (standard resolution mode), and a 12 s exposure time. Image data were processed using OnDemand3D computer software (CyberMed SCANORA 3D 2013, Soredex), Statistical analysis utilized SPSS v.26 software (IBM) with a significance level of < 0.05. The Vertucci classification, comprising eight main categories [14], formed the basis for categorizing canal configurations.

Type(I): (1–1) A single canal from the pulp chamber to the Apex.

Type (II): (2 − 1) Two separate canals leaving the chamber but merging short of the Apex to form a single canal.

Type (III): (1–2–1) A single canal from a pulp chamber that divides into two, and subsequently merges to exist as one.

Type (IV): (2–2) Two distinct canals from the pulp chamber to the apex.

Type (V): (1–2) A single canal leaving the chamber and dividing into two separate canals at the apex.

Type (VI): (2–1–2) Two separate canals leaving the pulp chamber, merging in the body of the root, and dividing again into two distinct canals short from the apex.

Type (VII): (1–2–1–2) A single canal that divides, merges, and exits into two distinct canals short from the apex.

Type (VIII): (3–3) three distinct canals within one root from the pulp chamber to the apex.

A X2 test assessed left and right tooth symmetry in males and females.

Results

250 CBCT images of the Syrian Subpopulation (140 for females,110 for males) containing (500) upper second molar have been assessed. The majority of them had three roots (90.4%) (Fig. 1), followed by two roots (4.8%), followed by one root (2.8%), followed by four roots (2%) (Table 1). The number of three roots was higher in females than in males, 91.4% and 89.1%; respectively, without any significant difference (P = 0.173).

Table 1 Numbers of roots in maxillary second molars

Second molar (n = 500)	Number of roots	Right	Left	Total	
Males 220 (44%)	One root	6 (5.5%)	6 (5.5%)	12 (5.5%)	
Two roots	4 (3.6%)	4 (3.6%)	8 (3.6%)	
Three roots	98 (89.1%)	98 (89.1%)	196 (89.1%)	
Four roots	2 (1.8%)	2 (1.8%)	4 (1.8)	
Females 280 (56%)	One root	-	2 (1.4%)	2 (0.7%)	
Two roots	8 (5.7%)	8 (5.7%)	16 (5.7%)	
Three roots	128 (91.4%)	128 (91.4%)	256 (91.4%)	
Four roots	4 (2.9%)	2 (1.4%)	6 (2.1%)	
Total 500 (100%)	One root	6 (2.4%)	6(2.4%)	12(2.4%)	
Two roots	12 (4.8%)	12 (4.8%)	24 (4.8%)	
Three roots	226 (90.4%)	228(91.2%)	454(90.8%)	
Four roots	6 (2.4%)	4 (1.6%)	10(2%)	

In the three-rooted maxillary second molars, the root canal configuration was mainly Vertucci type I classification in the Distobuccally 93.4% (91.9% males,94.5% females) and palatal root 99.6% (99% males, 100% females). Mesiobuccally root showed all types of Vertucci classifications except Type VII and VIII. The most common types were type I (29.5%), when MB2 is present, type II Vertucci classification was the most common canal configuration with a ratio of 22.9% (28.3% males, 18.8% females), then type IV and VI (18.9%), and additional type (7.9%) (Table 2). The prevalence of a second mesiobuccally canal (MB2) was (70.5%) and higher in males than females 79.8–63.3%.

Fig. 1 Axial views showing bilateral symmetry in number of three separated roots in maxillary second molar; A: Coronal, B: Middle, and C: Apical

Table 2 Configuration of the root canal system in the maxillary second molars (n = 500)

Number of roots	Root	Type I	Type II	Type III	Type IV	Type V	Type VI	Additional	
One Root		6 (50%)	4 (33.3%)	-	-	-	-	2 (16.7%)	
Two Roots	B	8 (33.3%)	12 (50%)	-	4 (16.7%)	-	-	-	
P	24 (100%)	-	-	-	-	-	-	
Three Roots	MB	134 (29.5%)	104 (22.9%)	8 (1.8%)	86 (18.9%)	-	86 (18.9%)	36(7.9%)	
DB	424 (93.4%)	8 (1.8%)	12 (2.6%)	-	2(0.4%)	6 (1.3%)	2 (0.4%)	
P	452 (99.6%)	2 (0.4%)	-	-	-	-	-	
Four Roots	MB	10 (100%)	-	-	-	-	-	-	
MP	10 (100%)	-	-	-	-	-	-	
DB	10 (100%)	-	-	-	-	-	-	
DP	10 (100%)	-	-	-	-	-	-	

There were significant differences between males and females regarding the symmetry of the number of roots in maxillary second molars (P = 0.004). The symmetry ratio was 100% for males and 92.9% for females (Figs. 2, 3, and 4). Considering symmetry in the numbers and configuration of the root canal, 59.6% (60.9% males,58.6%% females) had no significant statistical difference between genders (P = 0.708) (Table 3).

Fig. 2 Axial views showing asymmetry in number of roots in maxillary second molar two roots in right side and only one root in left side; A: Coronal, B: Middle and C: Apical

Table 3 Bilateral symmetry of the number of root and root canals in maxillary second molars (summarized by gender)

Gender	Number of roots	P value	Number of root canals	P value	
	Symmetrical	Asymmetrical	0.004	Symmetrical	Asymmetrical	0.708	
Males (n = 110)	110 (100%)	-	(60.9%) 67	(39.1%) 43	
Females (n = 140)	130 (92.9%)	10 (7.1%)	(58.6%) 82	(41.4%) 85	
Total (n = 250)	240 (96%)	10 (4%)	(59.6%) 149	(40.4%) 101	

Fig. 3 Bilateral symmetrical case of an upper second molar with only one root within it three canals which is the third modification of this study A3(3–2–1); A-D Axial view, E, F Sagittal View

A set of additional modifications we found in our research (Fig. 5) which was similar to the one found in the maxillary first molars in Syrian sub population [15]:

Fig. 4 Bilateral symmetrical case of an upper second molar with two roots (Buccal root, containing two separate canals type IV of Vertucci classification and palatal root with only one canal; A, B Sagittal view, C, D 3D View, and E, F Axial View

Fig. 5 A set of additional modifications we found in the current research

Type A1 (2–1–2–1): Two canals leave the pulp chamber to meet inside the root to form one canal, then return to separate into two canals, ending with one apex.

Type A2 (2–3): Two canals leave the pulp chamber, and then one separates into two canals and ends with three different apexes.

Type A3 (3–2–1): Three canals leave the pulp chamber, then meet in two canals in the middle of the root, and they meet at the end of the root with one apex.

Type A4 (2–3–2): Two canals leave the pulp chamber, then one separates into two canals, then they return and converge, travel with the other canal, and end with two different apexes.

Type A5(2–3–1): Two canals leave the pulp chamber, then one separates into two canals, then they return and converge and end with one apex.

Type A6 (3–1–2): Three canals leave the pulp chamber, meet in one canal in the middle of the root, then return to branch into two canals at the end of the root, and end with two different apexes.

Discussion

The development of three-dimensional radiological diagnostic methods has sharpened prior knowledge of anatomical shapes, subsequently, increasing chances for successful endodontic treatment by understanding the morphology of root canal systems to disinfect and obturate these systems properly [16]. As The morphological differences in root canal systems are affected by several factors, such as gender, ethnicity, age, and geographical location [12, 17, 18], knowing the presence of symmetry in the numbers of roots and shapes of canals is beneficial in predicting before starting root canal morphology treatment by comparing the treated tooth with the opposite side within the same jaw [15]. To the best of our knowledge, this is the first study that provides detailed information on the number of roots, root canal morphology of the second upper molars in the Syrian subpopulation, and their bilateral symmetry in both genders. The root canals anatomy was categorized into eight types according to the Vertucci classification, the most commonly used classification in previous studies [19], and a set of six additional types observed and described in this study (Fig. 5).

Regarding the number of roots in maxillary second molars, the most frequently observed root numbers according to this study were three (90.4%), followed by two (4.8%), one root (2.8%), and four roots (2%). The percentages of the three roots in our study align with the range reported by publications (88.2% for the Qatari population and 93% for the Saudi population) [13, 20]. This relative consistency might be due to the contiguity of the geographical locations of the mentioned communities and the use of a similar methodology to determine the molar morphology (CBCT). On the other hand, diverse populations beyond the Middle East region had different prevalence ratios, such as Ng’s study on British society, where the prevalence of three roots was 100% [21]. Even with two or one-root assessments, societies like Greece (8% for two-roots), Canada (8.25% for two-roots), and China (10% for one-root) [22] showed no similarities to our findings which was 4.8% for two-roots and 2.8% for one root. This variety in geographic regions might be a reason for this difference. In addition, the dissimilarity between studies methods, for instance, the laboratory study on extracted teeth performed by Ng et al. may led to creating a less inclusive sample than the ones assessed via CBCT [21].

Regarding the root canals systems’ configurations in the current study, all of Vertucci’s classifications except type VII and Type VIII, in addition to six additional modifications (A1 = 2.6% A2 = 0.9% A3 = 0.9% A4 = 1.8% A5 = 1.3% A6 = 0.4%) were found in the mesial root of maxillary second molars (Fig. 5). Although this percentage is low, treating such root canal configurations is challenging [23]. While when the molar has only two roots, buccal and palatal, type I the most common in the buccal root, followed by types II and IV. Understanding this detail of the root canal anatomy is necessary to clean these canals of microbial biofilms, cleaning and shaping procedures, and irrigation protocols to achieve optimal endodontic treatment [24].

Addressing the mesial root, Type I was the most commonly noted (29.5%), followed by type II (22.9%), then IV and VI (18.9%), and 7.9% to additional types. The results of our study align with the findings of A. Madfa’s publication on the Saudi people as type I was the most prevalent, accounting for 50% of the cases [25]. Nevertheless, the most dominant configurations were type II (2 − 1) in Brazil and USA samples, and types II and III (1–2–1) were in Chinese populations [22].

The distal root in our study was mainly type I (93.4%), which settled with the results of Neelakantan, Ng, and Weng (96, 92, and 84.9%, respectively) [21, 26, 27].

The least common type was an additional type (0.4%), which agreed with Kim’s study on a sample of Korean society, as the additional type was found in 0.3% [28].

For the palatal root, the most common type was type I (99.6%), followed by type II (0.4%). While studies reported ran ging percentages of the presence of two canals in the palatal root, these percentages ranged between 1.12% [29], 1.82% [28], 6% [27], and 12.2% [26].

Considering the presence of the second mesiobuccally canal, it ranged from 11.53 to 93.7% globally [26]. Our study showed 70.5%, which was higher than Jing’s study on the Chinese sub-populations (13.4%) [30], and lower than Reis’s study on Brazilian (83.2%) [17].

All the previous agreements may be attributed to the similarity in radiographic interpretation, the thickness of the studied sections with a voxel size of 0.167 mm³, and a slice thickness of 1.0 mm [28]. Developmental variety and race mixing may be the causes of inconsistency.

In terms of gender relations, the first null hypothesis was rejected, as the presence of MB2 in our study was higher in males than females 79.8–63.3%. This finding agrees with Sert and Bayirli’s study performed on the Turkish population [31], and with Lee’s study on the Korean population as it was 48.7% for males and 30.8% for females [32]. On the other hand, other research has not proven a definite relationship between the presence of MB2 and the gender of individuals [33]. This variation in the incidence of an MB2 canal can be attributed to multiple factors, such as the study design (clinical/ laboratory), geographic region, and population studied.

For symmetry, few publications have compared the right and left teeth of the same individual [12, 34]. In this study, the symmetry ratios regarding the number of roots in our study were 96% (100% males, 92.9% females) with significant differences (P = 0.004) which means that the second null hypothesis was rejected. In comparison with other populations, this ratio is similar to those reported on the Saudi population 96.4% [35], and greater than those reported for the Indian population (70.8%) [34]. Although the research that studied the bilateral symmetry of the number of roots of the upper second molars was very few, it always indicates that the rates of symmetry have always been greater than asymmetry ratios [23].

Nevertheless, the configuration symmetry had different arrangements. For the Syrian population, there was no significant statistical difference between genders (P = 0.708). The percentage of symmetry in the entire sample was 59.6% (60.9% males,58.6% females), while the rest of the sample showed bilateral asymmetry. This type of asymmetry could be attributed to the variation in the complex anatomy of the MB root. This outcome is lower than Plotino’s study on a White Population of maxillary second molars, which showed perfect symmetry in root and canal morphology in 79.6% Of the 45 patients [12]. The difference in anatomical symmetry between the results of studies is due to differences in sample size, ethnicities, and regional population diversity. This is also higher than Dandache’s study on a Turkish Population which found symmetrical in only 38.8% of the patients in root canal configuration. The reason for this difference may be due to the use of Micro-CT in his study, which is more accurate and reliable than the CBCT used in this study [11].

C-shaped roots and canals were not examined in this study, in contrast to many studies that have examined the percentage of the presence of C-shape, and the percentages varied among several societies, such as the Iraqi, Saudi, Colombian, and Indian societies [34, 36–38].

The CBCT images used in the current study were collected only from the Syrian capital, Damascus, which may be considered a limitation. The national conflict at the time of collecting samples and the difficult situation in other Syrian cities, which affected providing CBCT imaging to patients, are the main reasons that limited sampling to the Syrian capital. However, this city’s population is mixed with all other Syrian cities, which can give rise to claim the results for the Syrian subpopulation. Nevertheless, future research investigation on the larger population that represents the entire Syrian community is paramount.

Conclusion

Within the limitations of this study, the following can be concluded about the Syrian subpopulation’s maxillary second molar root canal anatomy:

The most common anatomical form of the maxillary second molars was three separated roots with four canals. The prevalence of a second mesiobuccally canal (MB2) was (70.5%) and higher in males than females and type II Vertucci classification was the most common canal configuration. The gender factor had an impact on root number; males had a greater percentage of symmetrical number of roots than females. This information is valuable for dentists as it allows them to predict the presence of additional roots or canals when treating a patient who has already undergone treatment for a second molar on the opposite side.

Acknowledgements

The presented research is a part of Safaa Allawi MSc’s research which was approved by Damascus University.

Author contributions

S.A and E.T conceptualized the idea, read the CBCT images, and contributed to the writing and documentation. H.A. and M.A. conceptualized the idea and supervised the MSc’s thesis for S.A. Y.A.T contributed to the interpretation of data, revision, formatting, and reediting of the manuscript. All authors read and agreed to the published version of the manuscript.

Funding

This research was self-funded.

Data availability

Data can be requested by an Email to the corresponding author.

Declarations

Ethics approval and consent to participate

The Research Ethics Committee of the Faculty of Dentistry, Damascus University, Syria approved this research project (Approval number: (UDDS692—10092020/SRC-3236)).

Informed consent was obtained from all patients for the examination of their CBCT images as part of a study on the morphology of maxillary second molars.

Consent for publication

Informed consent was obtained from all patients for the publication of their CBCT images data as part of a study on the morphology of maxillary second molars.

Competing interests

The authors declare no competing interests.

Abbreviations

CT Computed tomography

CBCT Cone-beam computed tomography

micro-CT Micro-computed tomography

Publisher’s note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
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References

1. Peikoff M Christie W Fogel H The maxillary second molar: variations in the number of roots and canals Int Endod J 1996 29 6 365 9 10.1111/j.1365-2591.1996.tb01399.x 10332235
Peikoff M, Christie W, Fogel H. The maxillary second molar: variations in the number of roots and canals. Int Endod J. 1996;29(6):365–9.10332235 10.1111/j.1365-2591.1996.tb01399.x
2. Rwenyonyi C Kutesa A Muwazi L Buwembo W Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan population Int Endod J 2007 40 9 679 83 10.1111/j.1365-2591.2007.01265.x 17608678
Rwenyonyi C, Kutesa A, Muwazi L, Buwembo W. Root and canal morphology of maxillary first and second permanent molar teeth in a Ugandan population. Int Endod J. 2007;40(9):679–83.17608678 10.1111/j.1365-2591.2007.01265.x
3. Wolf TG Paqué F Woop A-C Willershausen B Briseño-Marroquín B Root canal morphology and configuration of 123 maxillary second molars by means of micro-CT Int J Oral Sci 2017 9 1 33 7 10.1038/ijos.2016.53 28106044
Wolf TG, Paqué F, Woop A-C, Willershausen B, Briseño-Marroquín B. Root canal morphology and configuration of 123 maxillary second molars by means of micro-CT. Int J Oral Sci. 2017;9(1):33–7.28106044 10.1038/ijos.2016.53
4. Tamse A Kaffe I Fishel D Zygomatic arch interference with correct radiographic diagnosis in maxillary molar endodontics Oral Surg Oral Med Oral Pathol 1980 50 6 563 5 10.1016/0030-4220(80)90441-7 6935614
Tamse A, Kaffe I, Fishel D. Zygomatic arch interference with correct radiographic diagnosis in maxillary molar endodontics. Oral Surg Oral Med Oral Pathol. 1980;50(6):563–5.6935614 10.1016/0030-4220(80)90441-7
5. 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 10.1016/j.joen.2012.03.026 22703664
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):977–82.22703664 10.1016/j.joen.2012.03.026
6. Aksoy U Küçük M Versiani M Orhan K Publication trends in micro-CT endodontic research: a bibliometric analysis over a 25‐year period Int Endod J 2021 54 3 343 53 10.1111/iej.13433 33075147
Aksoy U, Küçük M, Versiani M, Orhan K. Publication trends in micro-CT endodontic research: a bibliometric analysis over a 25‐year period. Int Endod J. 2021;54(3):343–53.33075147 10.1111/iej.13433
7. Martins JN Versiani MA CBCT and micro-CT on the study of root canal anatomy root Canal Anat Permanent Dentition 2019 89 180
Martins JN, Versiani MA. CBCT and micro-CT on the study of root canal anatomy. The root canal anatomy in permanent dentition. 2019;89:180.
8. Perrini N, Versiani MA. Historical overview of the studies on root canal anatomy. The root canal anatomy in permanent dentition. 2019:3–15.
9. Patel S Dawood A Whaites E Pitt Ford T New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems Int Endod J 2009 42 6 447 62 10.1111/j.1365-2591.2008.01530.x 19298577
Patel S, Dawood A, Whaites E, Pitt Ford T. New dimensions in endodontic imaging: part 1. Conventional and alternative radiographic systems. Int Endod J. 2009;42(6):447–62.19298577 10.1111/j.1365-2591.2008.01530.x
10. Ok E Altunsoy M Nur BG Aglarci OS Çolak M Güngör E A cone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population Acta Odontol Scand 2014 72 8 701 6 10.3109/00016357.2014.898091 24832561
Ok E, Altunsoy M, Nur BG, Aglarci OS, Çolak M, Güngör E. A cone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population. Acta Odontol Scand. 2014;72(8):701–6.24832561 10.3109/00016357.2014.898091
11. Dandache G Aksoy U Ozel MB Orhan K Anatomic Comparison of Contralateral Maxillary Second molars using high-resolution Micro-CT Symmetry 2023 15 2 420 10.3390/sym15020420
Dandache G, Aksoy U, Ozel MB, Orhan K. Anatomic comparison of contralateral maxillary second molars using high-resolution micro-CT. Symmetry. 2023;15(2):420.10.3390/sym15020420
12. Plotino G Tocci L Grande NM Testarelli L Messineo D Ciotti M Symmetry of root and root canal morphology of maxillary and mandibular molars in a white population: a cone-beam computed tomography study in vivo J Endod 2013 39 12 1545 8 10.1016/j.joen.2013.09.012 24238444
Plotino G, Tocci L, Grande NM, Testarelli L, Messineo D, Ciotti M, et al. Symmetry of root and root canal morphology of maxillary and mandibular molars in a white population: a cone-beam computed tomography study in vivo. J Endod. 2013;39(12):1545–8.24238444 10.1016/j.joen.2013.09.012
13. Al-Obaid MM Al-Sheeb FA Root Canal morphology of Maxillary First and Second molars in a Qatari Population: A Cone-Beam Computed Tomography Study Eur Dent Res Biomaterials J 2021 2 01 34 8 10.1055/s-0041-1731625
Al-Obaid MM, Al-Sheeb FA. Root canal morphology of maxillary first and second molars in a Qatari population: a cone-beam computed tomography study. Eur Dent Res Biomaterials J. 2021;2(01):34–8.10.1055/s-0041-1731625
14. Vertucci FJ Root canal morphology and its relationship to endodontic procedures Endodontic Top 2005 10 1 3 29 10.1111/j.1601-1546.2005.00129.x
Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endodontic Top. 2005;10(1):3–29.10.1111/j.1601-1546.2005.00129.x
15. Allawi S Madarati AA Al-Tayyan M Evaluation of roots and root canals’ morphology of maxillary premolars in a Syrian subpopulation using cone-beam computed tomography Saudi Endodontic J 2023 13 2 168 76 10.4103/sej.sej_173_22
Allawi S, Madarati AA, Al-Tayyan M. Evaluation of roots and root canals’ morphology of maxillary premolars in a Syrian subpopulation using cone-beam computed tomography. Saudi Endodontic J. 2023;13(2):168–76.10.4103/sej.sej_173_22
16. Restrepo-Restrepo F Cañas‐Jiménez S Romero‐Albarracín R Villa‐Machado P Pérez‐Cano M Tobón‐Arroyave S Prognosis of root canal treatment in teeth with preoperative apical periodontitis: a study with cone‐beam computed tomography and digital periapical radiography Int Endod J 2019 52 11 1533 46 10.1111/iej.13168 31211862
Restrepo-Restrepo F, Cañas‐Jiménez S, Romero‐Albarracín R, Villa‐Machado P, Pérez‐Cano M, Tobón‐Arroyave S. Prognosis of root canal treatment in teeth with preoperative apical periodontitis: a study with cone‐beam computed tomography and digital periapical radiography. Int Endod J. 2019;52(11):1533–46.31211862 10.1111/iej.13168
17. Al-Fouzan KS Ounis HF Merdad K Al‐Hezaimi K Incidence of canal systems in the mesio‐buccal roots of maxillary first and second molars in Saudi Arabian population Australian Endodontic J 2013 39 3 98 101 10.1111/j.1747-4477.2010.00289.x
Al-Fouzan KS, Ounis HF, Merdad K, Al‐Hezaimi K. Incidence of canal systems in the mesio‐buccal roots of maxillary first and second molars in Saudi Arabian population. Australian Endodontic J. 2013;39(3):98–101.10.1111/j.1747-4477.2010.00289.x
18. Reis AGDAR Grazziotin-Soares R Barletta FB Fontanella VRC Mahl CRW Second canal in mesiobuccal root of maxillary molars is correlated with root third and patient age: a cone-beam computed tomographic study J Endod 2013 39 5 588 92 10.1016/j.joen.2013.01.003 23611373
Reis AGDAR, Grazziotin-Soares R, Barletta FB, Fontanella VRC, Mahl CRW. Second canal in mesiobuccal root of maxillary molars is correlated with root third and patient age: a cone-beam computed tomographic study. J Endod. 2013;39(5):588–92.23611373 10.1016/j.joen.2013.01.003
19. Karobari MI Parveen A Mirza MB Makandar SD Nik Abdul Ghani NR Noorani TY Root and root canal morphology classification systems Int J Dent 2021 2021 1 6682189 33679981
Karobari MI, Parveen A, Mirza MB, Makandar SD, Nik Abdul Ghani NR, Noorani TY, et al. Root and root canal morphology classification systems. Int J Dent. 2021;2021(1):6682189.33679981
20. Mashyakhy M Abu-Melha AS Analysis of bilateral symmetry of root canal anatomy in permanent dentition: an in vivo CBCT study in a Saudi Arabian population J Contemp Dent Pract 2021 22 8 867 75 10.5005/jp-journals-10024-3163 34753837
Mashyakhy M, Abu-Melha AS. Analysis of bilateral symmetry of root canal anatomy in permanent dentition: an in vivo CBCT study in a Saudi Arabian population. J Contemp Dent Pract. 2021;22(8):867–75.34753837 10.5005/jp-journals-10024-3163
21. Ng YL Aung T Alavi A Gulabivala K Root and canal morphology of Burmese maxillary molars Int Endod J 2001 34 8 620 30 10.1046/j.1365-2591.2001.00438.x 11762499
Ng YL, Aung T, Alavi A, Gulabivala K. Root and canal morphology of Burmese maxillary molars. Int Endod J. 2001;34(8):620–30.11762499 10.1046/j.1365-2591.2001.00438.x
22. Ghasemi N Rahimi S Shahi S Samiei M Reyhani MF Ranjkesh B A review on root anatomy and canal configuration of the maxillary second molars Iran Endodontic J 2017 12 1 1
Ghasemi N, Rahimi S, Shahi S, Samiei M, Reyhani MF, Ranjkesh B. A review on root anatomy and canal configuration of the maxillary second molars. Iran Endodontic J. 2017;12(1):1.
23. Allawi S Ayoubi H Al-Tayyan M Toutangy E Tolibah YA Evaluation of roots, root canal morphology, and bilateral symmetry of maxillary first molars in a Syrian subpopulation using cone beam computed tomography Clin Experimental Dent Res 2023 9 6 1149 55 10.1002/cre2.782
Allawi S, Ayoubi H, Al-Tayyan M, Toutangy E, Tolibah YA. Evaluation of roots, root canal morphology, and bilateral symmetry of maxillary first molars in a Syrian subpopulation using cone beam computed tomography. Clin Experimental Dent Res. 2023;9(6):1149–55.10.1002/cre2.782
24. Siqueira JF, Rôças IN, Ricucci D. Internal tooth anatomy and root canal instrumentation. The root canal anatomy in permanent dentition. 2019:277–302.
25. Madfa AA, Almansour MI, Al-Zubaidi SM, Alghurayes AH, AlDAkhayel SD, Alzoori FI et al. Cone beam computed tomography analysis of the root and canal morphology of the maxillary second molars in a Hail province of the Saudi population. Heliyon. 2023;9(9).
26. Neelakantan P Subbarao C Ahuja R Subbarao CV Gutmann JL Cone-beam computed tomography study of root and canal morphology of maxillary first and second molars in an Indian population J Endod 2010 36 10 1622 7 10.1016/j.joen.2010.07.006 20850665
Neelakantan P, Subbarao C, Ahuja R, Subbarao CV, Gutmann JL. Cone-beam computed tomography study of root and canal morphology of maxillary first and second molars in an Indian population. J Endod. 2010;36(10):1622–7.20850665 10.1016/j.joen.2010.07.006
27. Weng X-L Yu S-B Zhao S-L Wang H-G Mu T Tang R-Y Root canal morphology of permanent maxillary teeth in the Han nationality in Chinese Guanzhong area: a new modified root canal staining technique J Endod 2009 35 5 651 6 10.1016/j.joen.2009.02.010 19410077
Weng X-L, Yu S-B, Zhao S-L, Wang H-G, Mu T, Tang R-Y, et al. Root canal morphology of permanent maxillary teeth in the Han nationality in Chinese Guanzhong area: a new modified root canal staining technique. J Endod. 2009;35(5):651–6.19410077 10.1016/j.joen.2009.02.010
28. Kim Y Lee S-J Woo J Morphology of maxillary first and second molars analyzed by cone-beam computed tomography in a Korean population: variations in the number of roots and canals and the incidence of fusion J Endod 2012 38 8 1063 8 10.1016/j.joen.2012.04.025 22794206
Kim Y, Lee S-J, Woo J. Morphology of maxillary first and second molars analyzed by cone-beam computed tomography in a Korean population: variations in the number of roots and canals and the incidence of fusion. J Endod. 2012;38(8):1063–8.22794206 10.1016/j.joen.2012.04.025
29. Yang B Lu Q Bai Q Zhang Y Liu X Liu Z Evaluation of the prevalence of the maxillary molars with two palatal roots by cone-beam CT. Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese J Stomatology 2013 48 6 359 62
Yang B, Lu Q, Bai Q, Zhang Y, Liu X, Liu Z. Evaluation of the prevalence of the maxillary molars with two palatal roots by cone-beam CT. Zhonghua Kou Qiang Yi Xue Za Zhi = Zhonghua Kouqiang Yixue Zazhi = Chinese. J Stomatology. 2013;48(6):359–62.
30. Jing Y Ye X Liu D Zhang Z Ma X Cone-beam computed tomography was used for study of root and canal morphology of maxillary first and second molars Beijing Da Xue Xue bao Yi xue ban = J Peking Univ Health Sci 2014 46 6 958 62
Jing Y, Ye X, Liu D, Zhang Z, Ma X. Cone-beam computed tomography was used for study of root and canal morphology of maxillary first and second molars. Beijing Da Xue Xue bao Yi xue ban = J Peking Univ Health Sci. 2014;46(6):958–62.
31. Sert S Bayirli GS Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population J Endod 2004 30 6 391 8 10.1097/00004770-200406000-00004 15167464
Sert S, Bayirli GS. Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population. J Endod. 2004;30(6):391–8.15167464 10.1097/00004770-200406000-00004
32. Lee J-H, Kim K-D, Lee J-K, Park W, Jeong JS, Lee Y et al. Mesiobuccal root canal anatomy of Korean maxillary first and second molars by cone-beam computed tomography. Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology. 2011;111(6):785–91.
33. Abarca J Gómez B Zaror C Monardes H Bustos L Cantín M Assessment of mesial root morphology and frequency of MB2 canals in maxillary molars using cone beam computed tomography Int J Morphol 2015 33 4 1333 7 10.4067/S0717-95022015000400023
Abarca J, Gómez B, Zaror C, Monardes H, Bustos L, Cantín M. Assessment of mesial root morphology and frequency of MB2 canals in maxillary molars using cone beam computed tomography. Int J Morphol. 2015;33(4):1333–7.10.4067/S0717-95022015000400023
34. Felsypremila G Vinothkumar TS Kandaswamy D Anatomic symmetry of root and root canal morphology of posterior teeth in Indian subpopulation using cone beam computed tomography: a retrospective study Eur J Dentistry 2015 9 04 500 7 10.4103/1305-7456.172623
Felsypremila G, Vinothkumar TS, Kandaswamy D. Anatomic symmetry of root and root canal morphology of posterior teeth in Indian subpopulation using cone beam computed tomography: a retrospective study. Eur J Dentistry. 2015;9(04):500–7.10.4103/1305-7456.172623
35. Mirza M, Gufran K, Alhabib O, Alafraa O, Alzahrani F, Abuelqomsan M et al. CBCT based study to analyze and classify root canal morphology of maxillary molars-a retrospective study. Eur Rev Med Pharmacol Sci. 2022;26(18).
36. Abdalrahman K Talabani R Kazzaz S Babarasul D Assessment of C-Shaped canal morphology in Mandibular and Maxillary Second molars in an Iraqi subpopulation using Cone‐Beam Computed Tomography Scanning 2022 2022 1 4886993 35360525
Abdalrahman K, Talabani R, Kazzaz S, Babarasul D. Assessment of C-shaped canal morphology in mandibular and maxillary second molars in an Iraqi subpopulation using cone‐beam computed tomography. Scanning. 2022;2022(1):4886993.35360525
37. Mashyakhy M Chourasia HR Jabali A Almutairi A Gambarini G Analysis of fused rooted maxillary first and second molars with merged and C-shaped canal configurations: prevalence, characteristics, and correlations in a Saudi Arabian population J Endod 2019 45 10 1209 18 10.1016/j.joen.2019.06.009 31378339
Mashyakhy M, Chourasia HR, Jabali A, Almutairi A, Gambarini G. Analysis of fused rooted maxillary first and second molars with merged and C-shaped canal configurations: prevalence, characteristics, and correlations in a Saudi Arabian population. J Endod. 2019;45(10):1209–18.31378339 10.1016/j.joen.2019.06.009
38. Marcano-Caldera M, Mejia-Cardona JL, del Pilar Blanco-Uribe M, Chaverra-Mesa EC, Rodríguez-Lezama D, Parra-Sánchez JH. Fused roots of maxillary molars: characterization and prevalence in a latin American sub-population: a cone beam computed tomography study. Restor Dentistry Endodontics. 2019;44(2).
