|
ORIGINAL RESEARCH |
https://doi.org/10.5005/jp-journals-10048-0111 |
Evaluation of Root Canal Configuration of Mandibular Premolars Using CBCT in a Defined Population of North India
1Department of Conservative Dentistry and Endodontics, Sudha Rustagi Dental College, Faridabad, Haryana, India
2Prosthodontist, Private Practitioner, New Delhi, India
Corresponding Author: Ashima Garg Sood, Department of Conservative Dentistry and Endodontics, Sudha Rustagi Dental College, Faridabad, Haryana, India, Phone: +91 9971444100, e-mail: drashimasood@gmail.com
How to cite this article: Sood AG, Sood A. Evaluation of Root Canal Configuration of Mandibular Premolars Using CBCT in a Defined Population of North India. Cons Dent Endod J 2022;7(2):31–34.
Source of support: Nil
Conflict of interest: None
Received on: 29 April 2023; Accepted on: 01 July 2023; Published on: 03 August 2024
ABSTRACT
Aim: The aim of the study was to evaluate the canal configuration in the mandibular premolars in Delhi/NCR population of North India using cone-beam computed tomography (CBCT).
Materials and methods: About 120 CBCT scans were assessed for the root canal configuration in the mandibular premolar according to Vertucci classification. The existence of bilateral symmetry of configuration in the right- and left-side premolars and any gender difference was also studied. Chi-square test was used for statistical analysis.
Results: Type I configuration was the most common in both mandibular premolars. In mandibular first premolar, there was 32.3% chance of canal variation from type I, and in the second premolar, approximately, 18.2% chances of variation exists. No gender difference was observed and bilateral symmetrical existence of canal configuration was seen.
Conclusion: The most prevalent configuration in mandibular premolars is type I. In the mandibular second premolar, chances of variant configuration are less as compared with the first premolar.
Keywords: Computed tomography, Canal configuration, Mandibular premolar, Mandibular premolars, Vertucci classification.
INTRODUCTION
A major contributing factor for successful endodontic treatment is detailed knowledge of root canal morphology. The internal anatomy of a canal system may demonstrate additional canals, lateral and accessory canals, diverse canal shapes, fins, and isthmuses. Its understanding is necessary for complete debridement, disinfection, and obturation of canals and thereby improving the prognosis of the treatment.1 Mandibular premolar teeth tend to vary greatly from the normal anatomy.2–4 Slowey reported that the mandibular premolars were the most difficult teeth to treat endodontically.5 These teeth predominantly encounter treatment failures and posttreatment flare-ups mainly due to the presence of too much variation in their morphology.1 The incidence of the number of roots and canals reported in anatomic studies varies greatly in literature in both mandibular premolars.6–10 The variation has been attributed to ethnicity, racial, and regional predispositions.10,11 The difference has been seen in Chinese,7 Iranian,2,8 Turkish,12 and Spanish populations.13
Identifying the configuration of canals has been done in the past using methods such as radiography and sectioning,2 clearing, and staining,14,15 or micro-CT scanning.16 The cone-beam computed tomography (CBCT) scanning was introduced in the field of endodontics in 1990. This noninvasive, 3D imaging technique has many endodontic applications including intense morphological analysis which is beneficial in identifying canal configuration.17–19 Neelakantan et al.20 in their study reported that the accuracy of CBCT was comparable to the modified canal staining and clearing techniques in the identification of root canal anatomy The added advantage of using CBCT is that any gender difference, bilateral existence of varied configuration can also be evaluated. Previous studies have evaluated the configuration of canals in mandibular premolars in the South Indian population,9,15 Gujarati population21 but not many studies have been reported for the identification of canal configuration mandibular premolars with any gender difference in the North Indian population.
As ethnicity has been considered a contributing factor in the existence of variation, the study was planned with an aim to evaluate the variations in canal configuration in mandibular first and second premolar using CBCT in Delhi/NCR population of North India. Also, the occurrence of bilateral symmetry or any gender difference was evaluated.
MATERIALS AND METHODS
About 120 CBCT scans were collected from archives of the radiology database. Fifty-four scans were of females and sixty-six scans were of males. Scans with fully erupted premolars present bilaterally were included in the study. Teeth with any periapical lesion, any previously filled or endodontically treated teeth, or teeth with any open apices, or missing premolar on one side were excluded from the study. Out of 120 scans, in 7 scans, the first premolar teeth were not taken into consideration, and in 10 scans, the second premolars were not evaluated as per exclusion criteria. So, a total of 226 first premolars and 220 second premolars were evaluated. The CBCT used had specifications with an exposure time of 8–9 seconds at 120 kVp, 18.5 MPa, and voxel size ranging from 4 to 15 mm.
The scans were studied in all three spatial directions – axial, sagittal, and coronal. Serial CBCT images were assessed by repeatedly moving the toolbar from the floor of the pulp chamber to the apex to precisely ascertain the canal configuration according to Vertucci classification.22 As this classification has only eight configurations, if any other configuration was detected, those canals were classified according to the classification given by Sert and Bayirli.14 The number and percentage of each configuration were calculated bilaterally for both the mandibular premolars. Data analysis was done using SPSS software. For statistical analysis, the Chi-square test was used to see the significance level between right- and left-side premolars and between males and females. The level of significance was set at 0.05
RESULTS
The results showed that in mandibular first premolar, the most common configuration was type I for both right-side (64.6%) and left-side (70.8%), followed by type V and then type III. The percentage of type II was 1.8% only. Type IV, type VI, and type IX configurations were rarely seen (0.4%) (Table 1). So there was 32.3% chance of canal variation from type I.
| Vertucci classification | Type I (1–1) | Type II (2–1) | Type III (1–2–1) | Type IV (2–2) | Type V (1–2) | Type VI (2–1–2) | Type VII (1–2–1–2) | Type VIII (3–3) | Type IX (1–3) (Sert and Bayirli 2004) |
|---|---|---|---|---|---|---|---|---|---|
| Right first premolar (n = 113) | 73 (64.6%) | 1 (0.9%) | 12 (10.6%) | 1 (0.9%) | 25 (22.1%) | 1 (0.9%) | – | – | – |
| Left first premolar (n = 113) | 80 (70.8%) | 3 (2.7%) | 8 (7.1%) | – | 21 (18.6%) | – | – | – | 1 (0.4%) |
| Total (n = 226) | 153 (67.7%) | 4 (1.8%) | 20 (8.8%) | 1 (0.4%) | 46 (20.4%) | 1 (0.4%) | – | – | 1 |
| p-value | 0.197 NS | 0.311 NS | 0.242 NS | 0.5 NS | 0.310 NS | 0.5 NS |
In the mandibular second premolar, type I was the most common configuration on both right-side (84.2%) and left-side (79.5%), followed by type II (7.7%) and then by type V (Table 2). Type IX configuration was seen only in one scan which was present bilaterally (0.9%) (Fig. 1). In none of the premolars, type VII and type VIII were present. Variation from type I configuration was found in 18.2% of second premolars. The statistical analysis showed no significant difference on right- and left-side of the premolar for all the types of configurations. When canal configuration was compared between males and females, statistically, a nonsignificant difference was present (Table 3). Though in females, predominantly, type I configuration was present in the first premolar, the difference was statistically not significant. In the second premolar, again there was no gender difference.
| Vertucci classification | Type I (1–1) | Type II (2–1) | Type III (1–2–1) | Type IV (2–2) | Type V (1–2) | Type VI (2–1–2) | Type VII (1–2–1–2) | Type VIII (3–3) | Type IX (1–3) (Sert and Bayirli 2004) |
|---|---|---|---|---|---|---|---|---|---|
| Right second premolar (n = 108) | 91 (84.2%) | 8 (7.4%) | 3 (2.8%) | – | 5 (4.6%) | – | – | – | 1 (0.9%) |
| Left second premolar (n = 112) | 89 (79.5%) | 9 (8%) | 4 (3.6%) | – | 9 (8%) | – | – | – | 1 (0.9%) |
| Total (n = 220) | 180 (81.8%) | 17 (7.7%) | 7 (3.2%) | – | 14 (6.4%) | – | – | – | 2 (0.9%) |
| p-value | 0.175 NS | 0.531 NS | 0.520 NS | – | 0.225 NS | – | – | – | 0.742 NS |
Figs 1A to C: (A and B) Showing type IX configuration in mandibular second premolar; (C) Showing bilateral type III configuration in mandibular first premolar
| Mandibular first premolar | Mandibular second premolar | |||||||
|---|---|---|---|---|---|---|---|---|
| Type I | II | III | V | Type I | II | III | V | |
| Males | 64.4% | 4.1% | 9% | 21.4% | 82% | 7.9% | 4.4% | 5.3% |
| Females | 72.7% | 1% | 9% | 15% | 82% | 10% | 3% | 4% |
| p-value | 0.122 NS | 0.160 NS | 0.595 NS | 0.152 NS | 0.105 NS | 0.322 NS | 0.476 NS | 0.504 NS |
DISCUSSION
Cone-beam computed tomography imaging can be an essential diagnostic tool in detecting complex canal variants. Michetti et al.19 reported a strong correlation between CBCT-acquired data and histological sections of teeth in the identification of root canals. As mandibular premolars can exhibit a lot of variation in canal configuration and fewer studies are available for identification of the same in the North Indian population, the study was planned to evaluate the configuration of canals in mandibular premolars using CBCT in a defined group of North Indian population.
Vertucci has classified the canal configurations into eight types. In this study, three teeth showed the division of a single canal into three canals, so they were classified as type IX according to the classification given by Sert and Bayirli14 who added 14 new classifications to Vertucci’s existing eight classifications. The results of the present study exhibited more variability in the canal system in the mandibular first premolar as compared with the second premolar. Type I configuration was most prevalent in both the premolars in the study. The results are in accordance with previous studies in which type I was the most common configuration but with varied percentages (Table 4).
| Study | Method | Mandibular first premolar | Mandibular second premolar | Population |
|---|---|---|---|---|
| Present study | CBCT | Type I – 67.7% | Type I – 81.8% | North Indian |
| Llena et al.13 | CBCT | Type I – 78.1% | Type I – 90.6% | Spanish |
| Yu et al.7 | CBCT | Type I – 86.8% | Type I – 97.2% | Chinese |
| Sobhani et al.23 | CBCT | Type I – 90.8% | Type I – 90.7% | Turkish |
| Shetty et al.9 | CBCT | Type I – 83.81% | Type I – 93.48% | South Indian |
| Singh and Pawar15 | Indian ink | Type I – 80% | Type I – 66% | South Asian Indian |
| Jain and Bahuguna21 | Clearing technique | Type I – 67.4% | Gujarati | |
| Khedmat et al.2 | Radiograph, staining | Type I – 88.47% | Iranian | |
| Liu N et al.16 | Micro-CT | Type I – 65.2% | Chinese | |
| Evren OK et al.12 | CBCT | Type I – 93.5% | Type I – 98.5% | Turkish |
The difference can be attributed to racial and genetic variations which may influence root canal anatomy and morphology.1 Another factor for varied results can be due to different methods for evaluation, such as clearing technique, staining, or micro-CT used in other studies. Also, the varying sample size in all the studies may influence the results.
In the present study, the occurrence of bilateral symmetry was seen and no gender difference was observed. Another study by Hajihassani also reported no difference in canal configuration in males and females in the Iranian population.1 On the contrary, a study done by Evren et al. reported gender differences, with males having a significantly higher incidence of the extra canal, whereas females have a higher chance of one canalled premolar in the Turkish population. They also found a higher incidence of two canals on the left-side (9.5%) than on the right-side (5.9%). Type I configuration was prominent on the right-side.12 In another radiographic study by Serman and Hasselgren, more women had multiple roots and canals than men in mandibular first premolar, whereas more men exhibited multiple roots or canals in the mandibular second premolar.23,24 The difference could be again attributed to ethnicity and varying sample size.
Mandibular premolars can present with complex canal anatomy, so it is important to seek the presence of variant canal configurations. As CBCT cannot be used routinely for identifying the configuration during endodontic treatment, intraoral periapical radiographs should be taken from at least three different angulations to identify the presence of existing variation.
CONCLUSION
The most prevalent configuration in mandibular premolars is type I. In the mandibular second premolar, the chances of variant configuration are less as compared with the first premolar.
Bilateral symmetry in canal configuration is present.
There was nonsignificant difference in gender for the type of canal configuration.
REFERENCES
1. Hajihassani N, Roohi N, Madadi K, et al. Evaluation of root canal morphology of mandibular first and second premolars using CBCT in a defined group of Dental patients in Iran. Hindawi Scientifica 2017;1–7. DOI: 10.1155/2017/1504341.
2. Khedmat S, Assadian H, Saravani AA. Root canal morphology of the mandibular first premolars in an Iranian population using cross–sections and radiography. J Endod 2010;36(2):214–217. DOI: 10.1016/j.joen.2009.10.002.
3. Nallapati S. Three canal mandibular first and second premolars: a treatment approach. A case report. J Endod 2005;31(6):474–476.
4. Baisden MK, Kulid JC, Weller N. Root canal configuration of the mandibular first premolar. J Endodon 1992;18(10):505–508. DOI: 10.1016/S0099-2399(06)81352-X.
5. Slowey RR. Root canal anatomy. Road map to successful endodontics. Dent Clin North Am 1979:23:555–573. PMID: 294389.
6. Cleghorn BM, Christie WH, Dong CC. The root and root canal morphology of the human mandibular first premolar: a literature review. J Endod 2007;33:509–516. DOI: 10.1016/j.joen.2006.12.004.
7. Yu X, Guo B, Li K-Z, et al. Cone-beam computed tomography study of root canal morphology of mandibular premolars in a western Chinese population. BMC Med Imaging 2012;12:18. DOI: 10.1186/1471-2342-12-18.
8. Hosseinpour S, Kharazifard MJ, Khayat A, et al. Root canal morphology of permanent mandibular premolars in Iranian population: A systematic review. Iran Endod J 2016;11(3):150–156. DOI: 10.7508/iej.2016.03.001.
9. Shetty A, Hegde MN, Tahiliani D, et al. A three dimensional study of variations in root canal morphology using cone beam computed tomography in mandibular premolars in a south Indian population. J Clin Diagn Res 2014;8(8):22–24. DOI: 10.7860/JCDR/2014/8674.4707.
10. Cleghorn BM, Christie WH, Dong CC. The root and root canal morphology of the human mandibular second premolar: a literature review. J Endod 2007;33(9):1031–1037. DOI: 10.1016/j.joen.2007.03.020.
11. Trope M, Elfenbein L, Tronstad L. Mandibular premolars with more than one root canal in different race groups. J Endodon 1986;12(8):343–345. DOI: 10.1016/S0099-2399(86)80035-8.
12. Evren OK, Altunsoy M, Nur BG, et al. A cone beam computed tomography study of root canal morphology of maxillary and, mandibular premolars in a Turkish population. Acta Odontol Scand 2014;1–6. DOI: https://doi.org/10.3109/00016357.2014.898091.
13. Llena C, Fernandez J, Ortolani PS, et al. Cone-beam computed tomography analysis of root and root canal morphology of mandibular premolars in a Spanish population. Imaging Sci Dent 2014;44(3):221–227. DOI: 10.5624/isd.2014.44.3.221.
14. Sert S, Bayirli GS. Evaluation of root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population. J Endodon 2004;30(6):391–398. DOI: 10.1097/00004770-200406000-00004.
15. Singh S, Pawar M. Root canal morphology of South Asian Indian mandibular premolar teeth. J Endod 2014;40(9):1338–1341. DOI: 10.1016/j.joen.2014.03.021.
16. Liu N, Li X, Liu N, et al. A micro-computed tomography study of the root canal morphology of the mandibular first premolar in a population from southwestern China. Clin Oral Investig 2013;17(3):999–1007. DOI: 10.1007/s00784-012-0778-1.
17. Scarfe WC, Levin MD, Gane M, et al. Use of cone beam computed tomography in endodontics. Int J Dent 2009;2009:1–20. DOI: 10.1155/2009/634567.
18. Matherne RP, Angelpoulos C, Khulid JC, et al. Use of cone-beam computed tomography to identify root canal systems in vitro. J Endod 2008;34(1):87–89. DOI: 10.1016/j.joen.2007.10.016.
19. Michetti J, Maret D, Mallet JP, et al. Validation of cone beam computed tomography as a tool to explore root canal anatomy. J Endod 2010;36(7):1187–1190. DOI: 10.1016/j.joen.2010.03.029.
20. 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 morphology. J Endod 2010;36(9):1547–1551. DOI: 10.1016/j.joen.2010.05.008.
21. Jain A, Bahuguna R. Root canal morphology of mandibular first premolar in a Gujarati population – an in vitro study. Dent Res J 2011;8(3):118–122. PMID: 22013473.
22. Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58(5):589–599. DOI: 10.1016/0030-4220(84)90085-9.
23. Sobhani MA, Razmi H, Sadegh M. Evaluation of anatomy and morphology of human mandibular premolar teeth by cone-beam computed tomography in Iranian population. J Dent Med 2013;26(3):203–210. Available from: http://jdm.tums.ac.ir/article-1-5049-en.html.
24. Serman NJ, Hasselgren G. The radiographic incidence of multiple roots and canals in human mandibular premolar. Int Enod J 1992;25:234–237. DOI: 10.1111/j.1365-2591.1992.tb01155.x.
________________________
© The Author(s). 2022 Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted use, distribution, and non-commercial reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.