Journal of Indian Academy of Oral Medicine and Radiology

: 2015  |  Volume : 27  |  Issue : 4  |  Page : 580--583

Incidental findings of root canal anatomy of first and second molars with the eyes of cone beam computed tomography

Anjali Gupta, Nandika Babele, Tushar Phulambrikar, Siddharth Kumar Singh 
 Department of Oral Medicine and Radiology, Sri Aurobindo College of Dentistry, Indore, Madhya Pradesh, India

Correspondence Address:
Dr. Nandika Babele
F-501 Shalimar Township, AB Road, Indore, Madhya Pradesh


Cone beam computed tomography (CBCT) is an imaging modality that enables to visualize the dental structures in three dimensions, which is beyond the scope of conventional radiographs being used. A thorough understanding of the complexity of dental structures is necessary to devise a proper treatment plan and assure the best prognosis. This is made possible by the use of CBCT in all the specialties of dentistry. This case report presents the incidental findings as visualized on CBCT, viz., C-shaped canal and a molar with six root canals, which may pose a problem while being treated endodontically. Thus, the use of CBCT while treating them ensured the success of treatment and its prognosis.

How to cite this article:
Gupta A, Babele N, Phulambrikar T, Singh SK. Incidental findings of root canal anatomy of first and second molars with the eyes of cone beam computed tomography.J Indian Acad Oral Med Radiol 2015;27:580-583

How to cite this URL:
Gupta A, Babele N, Phulambrikar T, Singh SK. Incidental findings of root canal anatomy of first and second molars with the eyes of cone beam computed tomography. J Indian Acad Oral Med Radiol [serial online] 2015 [cited 2022 Oct 6 ];27:580-583
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Full Text


Radiographic examination is an essential component to understand the anatomy and finalize the treatment plan for the same. Various morphological alterations are cited in literature, which pose various endodontic, prosthetic, surgical, and periodontic challenges. [1] The amount of information gained from conventional radiographs and digitally captured periapical radiographs is limited by the fact that the three-dimensional anatomy of the area being radiographed is compressed into a two-dimensional image. Cone beam computed tomography (CBCT) proves to be an excellent method to produce undistorted three-dimensional images similar to CT for dental structures, thereby providing additional clinically relevant information. This article presents the incidental findings on CBCT of patients who were referred from the endodontics department, following some difficulties in root canal treatment. CBCT images were taken with Kodak CS 9300 software in 5 × 5 field of view (FOV), with the parameters of 90 kVp and 8 mA and using 90 μm voxel size. Cases with C-shaped root canal anatomy and a molar with six root canals have been reported.

 Case Report

C-shaped root canal

A 21-year-old male patient visited the department with a chief complaint of pain in lower right and left back tooth region. Intraoral periapical (IOPA) radiograph and CBCT of 37 and 47 were done following the clinical examination of carious teeth, and the patient was referred to the department of endodontics for root canal treatment (RCT). CBCT was advised subsequently, which showed the presence of C-shaped root canal in 47 and 37, which, according to the classification of Fan et al., [2] belonged to Type II category of C-shaped canal [Figure 1], [Figure 2], [Figure 3], [Figure 4].{Figure 1}{Figure 2}{Figure 3}{Figure 4}

Another 20-year-old female visited the department with the complaint of pain in lower left tooth region which clinically showed a deep carious lesion in 37. The patient was referred to the department of endodontics for RCT. CBCT of left mandibular quadrant was done, which showed C-shaped canal configuration in 37 belonging to type III category [2] [Figure 5] and [Figure 6].{Figure 5}{Figure 6}

A 23-year-old patient visited with the complaint of pain in mandibular right back teeth region which clinically showed a carious lesion in 47. It showed Type I category [2] of canal configuration on CBCT, as depicted in [Figure 7] and [Figure 8].{Figure 7}{Figure 8}

Molar with six root canals

A 23-year-old female patient came with a chief complaint of pain in upper left back tooth region. CBCT was done during RCT, which showed the presence of three roots and six root canals in 26 in the axial section. There were two canals in the mesial root, MB1 and MB2, one canal distally and three canals in the palatal root [Figure 9]. However, the canals were not evident on sagittal and coronal sections due to the superimposition of roots.{Figure 9}


A thorough knowledge of the root canal anatomy is required for achieving success in root canal therapy, along with diagnosis, treatment planning, and clinical expertise. [3],[4] CBCT takes an upper hand because of the three-dimensional view of the pulpal anatomy which is not evident in a 2D picture due to overlapping of various anatomical structures. One variation of the root canal system is the C-shaped canal configuration. Though most commonly found in mandibular second molars, [5] it may also occur in mandibular premolars, maxillary molars, and mandibular third molars. This finding is consistent with the findings seen in our cases. The incidence of C-shaped root canals in Indian population is 7.5% [6] in mandibular second molar. Fan et al. [2] classified the radiographic appearance of C-shaped canal configuration into three types [Figure 10]:{Figure 10}

Type I- The C-shaped canal appears as two distinct canals because the isthmus that links the mesial and distal "main" canals is very thin and, hence, not detected radiographically.

Type II- The mesial and distal canals assume their own individual course to the apex. Thus, there are apparently two distinct canals on the radiograph.

Type III- One canal continues its course to the apex giving the image of a distinct canal, whereas the other(s) proceed very close to or within the fused area, that is, the "web" between the two main roots in the apical third. Hence, the canal may seem to exit into the groove radiographically.

CBCT is essential for recognition of a C-shaped canal configuration before treatment as it can facilitate effective management. A number of variations have also been reported in maxillary molars with respect to roots and root canals, presenting with one, two, three, four, five, six, and seven root canals. CBCT in such cases provides a three-dimensional view of the root canal systems which is necessary for proper management, especially for endodontic consideration.


CBCT, indeed, is a great revolution in the imaging modalities used in dental and maxillofacial region in terms of its three-dimensional nature compared to the two-dimensional picture of conventional radiographs. Also, higher resolution, lower exposure, and lower cost than the previously available systems are the added advantages of the technique. CBCT should not be an indication for the routine cases requiring root canal treatment. Instead, it should be reserved for cases where the conventional root canal treatment procedures pose a difficulty during the course of the treatment and further exploration of root canal anatomy is required.

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Conflicts of interest

There are no conflicts of interest.


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