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 Table of Contents  
Year : 2020  |  Volume : 12  |  Issue : 4  |  Page : 240-243

Cone-beam computed tomography and microscope-assisted endodontic management of maxillary first premolar with three roots

Department of Conservative Dentistry and Endodontics, Annoor Dental College and Hospital, Muvattupuzha, Kerala, India
Date of Submission09-May-2020
Date of Decision11-Jul-2020
Date of Acceptance18-Jul-2020
Date of Web Publication13-Oct-2020

Correspondence Address:
Sruthi Moonnamkoottu Sunildath
Department of Conservative Dentistry and Endodontics, Annoor Dental College and Hospital, Muvattupuzha - 686 673, Kerala
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/IJDS.IJDS_71_20

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This study aims to report the endodontic management of the maxillary first premolar with three roots, using cone-beam computed tomography (CBCT) and an operating microscope. Most maxillary first premolars have two roots, buccal and palatal but it may rarely have three. The incidence of three separate roots in maxillary first premolars ranges between 0.5% and 6%. Variation in root anatomy makes root canal treatment challenging necessitating improved technology. CBCT imaging provides precise location and visualization of root morphology, and canal anatomy. Operating microscope provides better lighting, magnification, and visualization of the operative field that helps to recognize and locate additional roots canals. This article reports the endodontic management of a maxillary right first premolar with three separate roots.

Keywords: Cone-beam computed tomography, endodontic treatment, maxillary first premolar, operating microscope, variations in root morphology

How to cite this article:
Sunildath SM, Mathew J, George L, Vineet R V. Cone-beam computed tomography and microscope-assisted endodontic management of maxillary first premolar with three roots. Indian J Dent Sci 2020;12:240-3

How to cite this URL:
Sunildath SM, Mathew J, George L, Vineet R V. Cone-beam computed tomography and microscope-assisted endodontic management of maxillary first premolar with three roots. Indian J Dent Sci [serial online] 2020 [cited 2023 Mar 26];12:240-3. Available from: http://www.ijds.in/text.asp?2020/12/4/240/298035

  Introduction Top

Great variations occur in terms of the number of roots and root canals among teeth. Most maxillary first premolars have two roots, buccal and palatal. Buccal root sometimes may divide into mesiobuccal (MB) and distobuccal (DB) root.

The precise explanation for the presence of three roots is not known, but may be connected to the epithelial diaphragm of the Hertwig's root sheath. The differential growth of the epithelial diaphragm causes the division of the root trunk into two or three roots. When the enamel organ is grown, if three tongues such as extensions are developed from the horizontal epithelial diaphragm, three roots are formed.[1]

Precise interpretation of three-roots in maxillary premolars on preoperative radiographs can often be difficult. Success of root canal treatment will be higher, if these complex root canal configurations are anticipated earlier. Cone-beam computed tomography (CBCT) data provide precise location and visualization of root morphology and canal anatomy. This technology's ability to demonstrate geometrically accurate images in all three dimensions and the elimination of anatomic noise facilitates the evaluation of additional roots, root curvature, and anomalies within the canals.[2]

Almost 42% of endodontic failures were attributed to missed canals. Therefore, thorough knowledge of the root canal anatomy and advanced techniques help in improving treatment quality.[3] This report presents the endodontic management of a three-rooted maxillary right first premolar using CBCT for imaging and operative microscope.

  Case Report Top

A 43-year-old male patient was reported to the department of conservative dentistry and endodontics, with the chief complaint of pain in the upper right back teeth region since the past 1 week. The patient had noticed decayed tooth 6 months ago. He had pain (intermittent and radiating type) that specifically aggravated while chewing food and it started 1 week prior to the consultation at the department. Dental examination revealed deep Class II Disto occlusal (DO) caries with respect to the right maxillary first premolar. Response to thermal pulp testing was negative, indicating pulpal necrosis. The tooth was tender on vertical percussion. Periapical radiograph revealed, radiolucency involving enamel, dentin, pulp, and widening of periodontal ligament space [Figure 1]a. A diagnosis of necrotic pulp with symptomatic apical periodontitis of 14 was made and nonsurgical endodontic treatment was planned. Access opening was done, 2 distinct canal orifices were found (buccal and lingual). While checking the working length intraoral periapical (IOPA) X-ray, an additional periodontal ligament space (distally) was found, which suggested the presence of another root distally [Figure 1]b. CBCT evaluation was done which confirmed the presence of three roots irt 14 [DB, MB and palatal - [Figure 2]. Access preparation was reevaluated under microscope (Labomed dental operating surgical microscope, Prima DNT) and explored with DG-16 [Figure 3]. Access was extended mesiodistally to explore the MB or DB orifices. A DB orifice was located. The canal was negotiated; the working length was measured with an apex locator (Root ZX, J. Morita Mfg. Corp, Kyoto Japan) and confirmed with an IOPA radiograph [Figure 4]a. Cleaning and shaping was carried out using the step back technique, apical preparation was done up to size 35file, and coronal preparation to size 50 file, irrigation was done with 5.25% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Calcium hydroxide intracanal medicament was placed and the access cavity was temporarily restored with Cavit. The patient was recalled after 1 week, biomechanical preparation was repeated, followed by copious irrigation with sodium hypochlorite. Drying was achieved with paper points, the canals obturated with gutta-percha and AH plus sealer using the lateral condensation technique [Figure 5]. The access cavity was restored with composite and the patient remained asymptomatic.
Figure 1: (a): Preoperative periapical radiograph of tooth #14, (b) Working length radiograph suggestive of an extra periodontal ligament space distally

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Figure 2: Cone-beam computed tomography axial view and three-dimensional view of tooth 14, showing three separate roots

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Figure 3: Mesiobuccal, distobuccal, and palatal canal orifices of tooth #14

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Figure 4: (a) Working length radiograph showing three separate distinct canals, (b) Master cone radiograph

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Figure 5: (a) Periapical radiograph after obturation of the three root canals, (b) Occlusal view showing obturation of canal orifices

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  Discussion Top

The anatomy of maxillary premolars with three root canals, MB, DB, and palatal, is similar to that of adjacent maxillary molars, and they are sometimes referred to as small molars.[4] Ridiculous premolars, miniature three-canalled maxillary molars are the other terms proposed to describe this type of tooth.[5],[6]

Vertucci and Gegauff found that 5% of 400 maxillary first premolars had three canals: 0.5% existed as three canals in a single root, 0.5% existed as two canals in one root and one canal in a second root, and 4% existed as one canal in each of three separate roots.[7] The incidence of three separate roots in maxillary first premolars has been observed to vary between 0.5% and 6%.[8],[9],[10] Ahmad and Alenezi reported an incidence of 1.7%, it had either two buccal roots and a single palatal root or two palatal roots and a single buccal root. A study done by Gupta et al. in North Indian population found that the incidence of three-rooted premolars with three canals is 0.4%.[11] Studies have shown that there is a 90% chance of bilateral occurrence of three roots in premolar.[12] Ahmad and Alenezi reported a predilection of roots and root canals to be higher in males than females.[13] Studies among different populations have reported that male patients showed significantly greater number of roots and root canals compare to female patients.[14],[15],[16] This three-rooted premolar reported that here was in a male patient.

The undetected alterations in canal anatomy can lead to missed canals that will lead to failure of root canal treatment. Baruwa et al. have done a CBCT-based study and concluded that the missed canals have a significant impact on treatment prognosis. The prevalence of missed canals was 12.0%, and teeth with untreated canals were associated with periapical pathology in 82.6% of the cases.[17]

Vertucci's type VIII root canal configuration of premolar include tooth with three root canals in fused roots; with two root canals in a fused buccal roots and a single canal in the palatal root; three-rooted premolar with three root canals. Tooth described in this case report is Vertucci's type VIII, three-rooted premolar with three root canals.

Ahmed et al. in 2017, introduced a new classification system to categorize root and root canal configurations in an accurate, simple and reliable manner.[18] In that system, if tooth is multirooted, then the code nTN R1O-C-F R2O-C-F RnO-C-F should be used (TN, Tooth number; R, Root; O, Orifice; C, Canal; F, Foramen).3 14 MB1 DB1 P1 is the code for the tooth in this case report.

Various methods such as radiographic examination, root sectioning, and staining and clearing techniques have been adopted to demonstrate canal anatomy.[19] In periapical radiograph an abrupt loss of radiolucency in the pulp cavity and a greater mesiodistal root diameter in the middle third is an implication of the presence of an additional root in maxillary first premolar.[20] However, in this case, radiograph was unable to provide definitive information on the anatomical variation, so CBCT was taken.

The role of CBCT over conventional digital and film radiography in accurately determining the root morphology and canal configuration is well-established.[21],[22] Yadav et al. have reported a rare case of all premolars with three roots which was confirmed with CBCT.[23] In this case report, CBCT of tooth #14 confirmed the existence of two buccal roots and canals (MB and DB). CBCT helped in diagnosis by providing precise location and visualization of root morphology and canal anatomy.

The access preparation for the maxillary first premolar is generally oval or slot shaped, wider buccolingually, narrow mesiodistally, and centered mesiodistally between the cusp tips. If three canals are present, the external outline form becomes triangular, with the base on the buccal or palatal aspect depending on whether extra root is present buccally or palatally. In cases with extra root on buccal aspect, the access cavity may be extended mesiodistally on the buccal aspect so that the MB and DB corners of the triangle should be positioned directly over the corresponding canal orifices, as done in this case.

In this case, the operative microscope was used for improved clinical visualization. The advantages of using the operating microscope for conventional endodontics include enhanced visualization of root canal intricacies, which enables the clinician to investigate the root canal system and to clean and shape it more efficiently.[24]

  Conclusion Top

Variations in root canal anatomy can occur very often in endodontic practice leading to missed canals that leads to failure of root canal treatment. Hence, it is important that before starting any endodontic treatment, the clinician should take into consideration the possible variation of the root canal morphology. CBCT for diagnosis and operating microscope for managing cases with altered root canal anatomy may improve the long-term prognosis of endodontic treatment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form, the patient has given his consent for his images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

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Maibaum WW. Endodontic treatment of a “ridiculous” maxillary premolar: A case report. Gen Dent 1989;37:340-1.  Back to cited text no. 4
Sieraski SM, Taylor GN, Kohn RA. Identification and endodontic management of threecanalled maxillary premolars. J Endod 1989;15:2932.  Back to cited text no. 5
Goon WW. The “radiculous” maxillary premolar: Recognition, diagnosis, and case report of surgical intervention. Northwest Dent 1993;72:31-3.  Back to cited text no. 6
Vertucci FJ, Gegauff AJ. Root canal morphology of the maxillary first premolar. Am Dent Assoc 1979;99:194-8.  Back to cited text no. 7
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  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]

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