ORIGINAL RESEARCH |
https://doi.org/10.5005/jp-journals-10057-0215 |
To Evaluate the Prevalence of C-Shaped Canal in Mandibular Second Molars Using CBCT Analysis
1-6Department of Conservative Dentistry and Endodontics, Mahatma Gandhi Dental College & Hospital, Jaipur, Rajasthan, India
Corresponding Author: Aarushi Chopra, Department of Conservative Dentistry and Endodontics, Mahatma Gandhi Dental College & Hospital, Jaipur, Rajasthan, India, Phone: +91 7023659916, e-mail: aarushichopra1996@gmail.com
Received on: 25 February 2023; Accepted on: 21 March 2023; Published on: 16 September 2023
ABSTRACT
Aim: The goal of this study was to use cone-beam computed tomography (CBCT) to determine the prevalence of C-shaped canals in second mandibular molars.
Materials and methods: A total of 1,500 CBCT scans were screened and evaluated in Rajasthan patients. C-shaped canals in the second mandibular molars were discovered.
Results: In the second mandibular molars, the overall prevalence of C-shaped canals was 3.99%. There was no significant difference found based on gender or side of occurrence.
Conclusion: In comparison to other subpopulations, the prevalence of C-shaped canals in second mandibular molars in the Rajasthan population is high. During clinical work, clinicians should be aware of the possible asymmetry, different configurations along the root, and location of the danger zone of this anatomic variation.
How to cite this article: Chopra A, Raisingani D, Prasad AB, et al. To Evaluate the Prevalence of C-Shaped Canal in Mandibular Second Molars Using CBCT Analysis. J Mahatma Gandhi Univ Med Sci Tech 2022;7(3):67–71.
Source of support: Nil
Conflict of interest: None
Keywords: Cone-beam computed tomography, Endodontic therapy, Maxillary second molar
INTRODUCTION
The ability and thorough knowledge of the clinician to recognize both common and unusual anatomical variations is critical for favorable root canal treatment.1 In 1979, there was one such invention of an anatomical variation recognized as C-shaped by Cooke and Cox. The name was derived from the anatomical variation of root canals.2
The phenomenon of C-shaped canal configuration has been pronounced more in permanent mandibular second molars heeded by mandibular premolars, maxillary molars, and the least by mandibular third molars.3,4
Numerous etiological factors have been associated with the development of C-shaped canal morphology in dentistry since its introduction.5 The most believable explanation has been attributed to the omission of Hertwig’s epithelial root sheath fusion. A lingual groove on the tooth has been found to be the result of the failure of fusion of this sheath on the buccal side, and a buccal groove forms due to vice versa.6
The pervasiveness of C-shaped canals varies greatly between populations,2 especially in permanent second molars of the mandible, where it reaches from 2.7 to 5.2%.7 The prevalence has been reported to be as high as 30% in the Asian population. Gulabivala et al. reported a 22.4% incidence in Burmese patients.8 It has also been reported that Asians are more prone to it than whites. As a result, such an anatomical variation should be diagnosed earlier and managed with caution.
Various techniques, such as radiographs at various angulations, contrast injection into teeth, micro-CT, and spiral CT, can be used in the identification of C-shaped root canal anatomy. To assess the anatomy, CBCT has been shown to be a precise technique among these.
As previously stated, diagnosis influences tooth management, and as far as we are aware, no investigation has been conducted on the prevalence of C-shaped canals in mandibular second molars in Rajasthan. The current study was carried out to assess their prevalence using CBCT analysis. 9
MATERIALS AND METHODS
This observational study was conducted in Mahatma Gandhi Dental College and Hospital in Jaipur with CBCT scans obtained from private radiology centers after attaining Ethical Committee and Institutional Approval. The study population consisted of CBCT images of mandibular second molars of patients referred to these radiology centers. Images that were included for evaluation in the study consisted of scans with a small field of view (FOV) (60 60), voxel size 1, and high quality and resolution.
Furthermore, images with low quality and resolution, as well as a wide FOV, were excluded from the study. The observations were then noted as per the classification of Fan et al. (Fig. 1). At a 95% confidence level and 0.05 error rates, the sample statistics were processed out to be 502 samples in each gender using simple random sampling. At p = 0.05, the comparison was considered statistically significant.
Fig. 1: Anatomical classification by Fan et al.11
RESULT
As reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had C1 type of canal (Fig. 2), 1.5% had C2 type of canal (Fig. 3), and 1.5% had a C3 type of canal (Fig. 4), whereas, amongst the male population, 97.3% did not have C-shaped canal, whereas 2.4% had C1 canal. The intergroup comparison between males and females was statistically nonsignificant (p = 0.100). The overall prevalence for the C-shaped canal comes out to be 3.99% (Table 1 and Fig. 5).
Fig. 2: C1 configuration
Fig. 3: C2 configuration
Fig. 4: C3a configuration
| Absent | C1 | C2 | C3 | C4 | Chi-squared value | p-value | |
|---|---|---|---|---|---|---|---|
| Female | 194 | 5 | 3 | 3 | 1 | 7.780 | 0.100 (nonsignificant) |
| 94.2% | 2.4% | 1.5% | 1.5% | 0.5% | |||
| Male | 288 | 7 | 1 | 0 | 0 | ||
| 97.3% | 2.4% | 0.3% | 0.0% | 0.0% |
As reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had a C1 type of canal (Fig. 2), 1.5% had a C2 type of canal (Fig. 3), and 1.5% had C3 type of canal (Fig. 4), whereas, amongst the male population, 97.3% did not have C-shaped canal, whereas 2.4% had C1 canal. The intergroup comparison between males and females was statistically nonsignificant (p = 0.100). The overall prevalence of C-shaped canals was 3.99%
Fig. 5: Association between gender and C-shaped canals (observer I); as reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had C1 type of canal (Fig. 2), 1.5% had C2 type of canal (Fig. 3), and 1.5% had C3 type of canal (Fig. 4), whereas, amongst the male population, 97.3% did not have C-shaped canal whereas 2.4% had C1 canal. The intergroup comparison between males and females was statistically nonsignificant (p = 0.100). The overall prevalence of C-shaped canals was 3.99%
As reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had C1 type of canal, 1.5% had C2 type of canal, and 1.9% had C3 type of canal, whereas, among the males, 97.3% did not have a C-shaped canal, whereas 1.4% had a C1 canal and 1.0% had C2 shaped canals. The intergroup comparison between males and females was statistically nonsignificant (p = 0.238). The overall prevalence for C-shaped canals was 3.99% (Table 2 and Fig. 6).
| Absent | C1 | C2 | C3 | Chi-squared value | p-value | |
|---|---|---|---|---|---|---|
| Female | 194 | 5 | 3 | 4 | 4.244 | 0.238 (nonsignificant) |
| 94.2% | 2.4% | 1.5% | 1.9% | |||
| Male | 288 | 4 | 3 | 1 | ||
| 97.3% | 1.4% | 1.0% | 0.3% |
Fig. 6: Association between gender and C-shaped canals (observer II); as reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had C1 type of canal, 1.5% had C2 type of canal, and 1.9% were having C3 type of canal; whereas among the males 97.3% did not have C-shaped canal, whereas 1.4% had C1 canal, and 1.0% had C2 shaped canals. The intergroup comparison between males and females was statistically nonsignificant (p = 0.238). The overall prevalence of the C canal was 3.99%
The interobserver agreement between observer I and observer II for the location of the C-shaped canal was 93.90% (p = 0.001) (Table 3).
| Observer II | Interobserver agreement coefficient | p-value | |||||
|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | ||||
| Observer I | 0 | 482 | 0 | 0 | 0 | 0.939 | 0.001 |
| 100.0% | 0.0% | 0.0% | 0.0% | ||||
| 1 | 0 | 9 | 2 | 1 | |||
| 0.0% | 75.0% | 16.7% | 8.3% | ||||
| 2 | 0 | 0 | 3 | 1 | |||
| 0.0% | 0.0% | 75.0% | 25.0% | ||||
| 3 | 0 | 0 | 1 | 2 | |||
| 0.0% | 0.0% | 33.3% | 66.7% | ||||
| 4 | 0 | 0 | 0 | 1 | |||
| 0.0% | 0.0% | 0.0% | 100.0% | ||||
The interobserver agreement between observer I and observer II for the location of the C-shaped canal was 93.90% (p = 0.001)
STATISTICAL ANALYSIS
Microsoft Excel 2007 was used to enter the data and was analyzed with Statistical Package for the Social Sciences 23.0 version statistical software. Frequency and percentage were among the descriptive statistics. The current study’s significance level was set at 5%. To analyze the qualitative data Chi-squared test will be used and be collected by two observers to determine the result.
DISCUSSION
The anatomical structure of C-shaped root canals is complex. A clinician, especially an endodontist, should appreciate the aberration of root canal anatomy as the results of endodontic treatment directly depend on it (Vertucci). The presence of communications between two or more canals to each other is another peculiar feature that has been attributed to C-shaped canal morphology (Cooke and Cox). The early identification of a C-shaped root canal system prior to therapy can become adjunct to more effective endodontic therapeutic outcomes (Fan et al.). Mandibular second molars are more prone to such variations (Jin et al., and Jafarzadeh and Wu). Other teeth in which C-shaped canals have been appreciated are maxillary molars, maxillary laterals, mandibular first molars, and premolar teeth (Carlsen et al., Boveda et al., De Moor, Lu et al., and Yilmaz et al.).10
The root canal system’s cross-sectional morphology is inaccessible in a two-dimensional radiograph. As a result, from a two-dimensional radiograph detecting C-shaped canals is difficult. Awareness of the complex morphology is improved through CBCT, which is a three-dimensional imaging technique. Our research is based on CBCT imaging, which allows for high-quality assessment of abnormal morphological variations like C-shaped canals in permanent second molars of the mandible.7
A ”C” like root canal anatomy is not well defined but has often been described as a ”C” in general. This canal system was analyzed and modified using micro-CT by Fan et al. As per them, it needed to have all three of the following characteristics fused roots, a lingual or buccal groove on the surface of the root, and at least one canal cross-section belonging to the C1—an uninterrupted C with no division or separation, C2—the canal shape is a semicolon formed by the discontinuation of the C outline, C3—three, or two distinct canal configurations. In this study, the samples were observed and classified based on Fan’s method (Fig. 1).5
The age of the patient and C-shaped root canals showed no significant relationship according to the findings of this study, which is inconsistent with the findings of many previously done research which observed females to be at higher incidence of C-shaped canals, which is true with the current findings. In contrast, some studies have found that males have a higher prevalence of the same.11
The coronal thirds of the second molars of the mandible in axial sections of C-shaped canals are compared in this study to that used in previous research using Fan et al. classification method. The most frequent type found is the C1 configuration. This result is consistent with various research done by Janani et al., Shemesh et al., and Nejaim et al.11
Sort and Bayirli, using the clearing technique, assessed the relationship between the gender of the patient and the root canal morphology of the tooth. For nonsurgical endodontic treatment, they proposed that gender be taken into account during the preoperative evaluation process. A ”C” like root canal system was found in 13% of females and 7% of males. However, gender showed no significant distinctive feature in the occurrence of such canals.
A common complication associated with C-shaped canals is strip perforations which occur during the cleaning and shaping of teeth (Jin et al.) due to the presence of an unusual morphological feature, such as deep grooves located on the tooth buccally or lingually with a C-shaped canal system. The majority of previous research on C-shaped canals has found a merging of the roots on the buccal surface with a deep lingual groove which makes it altogether more essential to identify it earlier than treatment commencement (Chai and Thong, Jin et al., and Jung et al.). According to Zheng et al., none of the merged roots observed in their research had a groove buccally.12
Almost all teeth with a ”C” like root canal morphology are accompanied by a ”danger zone,” which is nothing but a thin dentin tissue in the vicinity of the root canal system. According to the previously stated literature, lingual radicular grooves are found in nearly all molars with a configuration of a C-shaped canal. Hence, Endodontists must always consider the risk of perforation at the position of the danger zone, especially on the lingual side of the root in such cases, to prevent them.
Such complexities of C-shaped root canal configuration often leads to unpredictable root canal therapy outcome. Thus, clinicians must always be cautious in case of variable root canal morphology and types of variably shaped canals to obtain optimum therapeutic results postendodontic treatment. Furthermore, for the successful clinical management of root canals with and without anatomic aberrations, dental operating microscopes, and optimum illumination are important adjuncts.11
CONCLUSION
The prompt detection of these fluctuating morphological aberrations facilitates efficient biomechanical preparation of teeth. Often the diagnosis and treatment done with the aid of 2D radiographs do not identify the correct position of the files on the terminus of ”C,” like the root canal, and thus, the utilization of CBCT as an adjunct in treatment cannot be emphasized enough.
A ”C” like root canal was found in a greater percentage of permanent second molars of the mandible from a Rajasthan sample. It has an extensive range of anatomical configurations, which makes debridement, filling, and restoration difficult. As a result, CBCT can inevitably be used in endodontic diagnosis and treatment.
As reported by observer I, among the females, 94.2% of the subjects did not have C-shaped canals, 2.4% had a C1 type of canal, 1.5% had a C2 type of canal, and 1.9% had a C3 type of canal, whereas among the males 97.3% did not have C-shaped canal whereas 1.4% had C1 canal, and 1.0% were having C2 shaped canals. The intergroup comparison between males, and females was statistically nonsignificant (p = 0.238). The overall prevalence of C canal was 3.99%.
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