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Year : 2019  |  Volume : 9  |  Issue : 3  |  Page : 216-221

Maxillary first premolar with three root canals: Four case reports

1 King Saud Medical City, SBE Resident; Department of Restorative Dental Science, Division of Endodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia
2 Department of Restorative Dental Science, Division of Endodontics, College of Dentistry, King Saud University, Riyadh, Saudi Arabia

Date of Web Publication16-Aug-2019

Correspondence Address:
Dr. Mariam Sameer Bafaqeeh
Dental Resident at King Saud Medical City, Saudi Board of Endodontics Resident, College of Dentistry, King Saud University, PO Box 230367, Riyadh 11321
Saudi Arabia
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/sej.sej_87_18

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Effective and successful endodontic treatment requires dentists to have adequate information on the clinical variations in root canal anatomy. The maxillary first premolars usually have two roots; however, rarely, the occurrence of three root canals has been reported. Existence of such variations should be considered and noted, to be managed well and not missed. Herein, we illustrate the diagnosis and clinical management of four clinical cases presented with three root-canaled maxillary first premolars.

Keywords: Anatomical variations, maxillary first premolars, root canal treatment, three canals, three roots

How to cite this article:
Bafaqeeh MS, Alqedairi A. Maxillary first premolar with three root canals: Four case reports. Saudi Endod J 2019;9:216-21

How to cite this URL:
Bafaqeeh MS, Alqedairi A. Maxillary first premolar with three root canals: Four case reports. Saudi Endod J [serial online] 2019 [cited 2020 Jul 14];9:216-21. Available from: http://www.saudiendodj.com/text.asp?2019/9/3/216/264649

  Introduction Top

The main purpose of root canal treatment is to eliminate infection and protect from further microbial invasion. Proper sealing of the canals proceeded by precise cleaning, shaping, and filling will help in effective treatment. Being knowledgeable of the anatomy and morphology of the root canal is considered a crucial factor toward achieving a successful endodontic therapy.[1]

The incidence of two root canals is the most predominant anatomy observed for maxillary first premolars, although disparity from the usual recognized anatomical norms has been asserted.[2],[3] The most frequent anatomical variation in these teeth is the existence of three roots with three root canals.[4] Supernumerary roots and accessory root canals may develop if disruption or folding in the epithelial sheath of Hertwig during dental development occurs.[5] An overall incidence of three-rooted maxillary first premolar has been addressed to range between 0.4% and 9.2% with an average of 1.7%.[4] Variations in the morphological studies are influenced by many factors, such as age, sex, study design, and methodology along with ethnicity.[4],[6] Among Saudi Arabian population, Atieh and Al-Nazhan et al. reported an incidence of 1.2% and 2.4%, respectively.[7],[8]

Three-rooted maxillary premolars were initially categorized based on external morphologies[9] and were later upgraded to four groups following cone-beam computed tomography (CBCT) imaging of internal and external morphologies.[10] In addition, different terminologies have been proposed including radiculuos premolars, mini-molars, and miniature three-canalled maxillary molars.[11],[12],[13]

Variations in the number of roots and canals in maxillary first premolar pose a major challenge for endodontic treatment.[11],[14] Moreover, recognizing such variations are essential for proper clinical management and satisfactory technical outcome as well as avoiding the possibility of oversight.[7] Improper endodontic treatment will leave unfilled spaces of the root canal system, which serve as avenues between dental pulp and the periodontium. Subsequently, such spaces may facilitate bacterial growth, leading to the development of periapical inflammations questioning the success of the root canal treatment.[7],[15] Almost 42% of endodontic failures were attributed to missed canals[16] that cause a failure of root canal therapy due to leakage.[17] Therefore, thorough knowledge of the root canal anatomy as well as using advanced techniques and technologies, such as magnifying tools and CBCT will help in improving treatment quality and avoiding such mishaps.[4]

This report presents the management of four cases with three root-canaled maxillary first premolar in Saudi patients.

  Case Reports Top

Case 1

A 26-year-old Saudi male patient was presented to the Endodontic Clinics at King Saud University Dental Hospital, complaining of spontaneous pain that is relieved by analgesics for the past couple of days related to his upper posterior tooth, pointing to left maxillary first premolar (#24). Tooth #24 was previously initiated 3 months ago in a private clinic as stated by the patient. He was with a noncontributory medical history.

Clinically, tooth #24 was filled with defective temporary restoration. Except the tenderness to percussion, no other abnormalities of palpation, probing depth, or mobility were detected. Radiographic examination revealed apical radiolucency related to the tooth with discontinuity of lamia dura. Moreover, anatomy of three root canals was also indicated radiographically [Figure 1]a and [Figure 1]b. The tooth was diagnosed as previously initiated pulp therapy with symptomatic apical periodontitis. A treatment plan was presented to the patient that was inclusive of nonsurgical root canal therapy.
Figure 1: Case 1: (a and b) Preoperative periapical radiographs of #24 reveal the complex root morphology of the premolar, (c) clinical photo of access cavity, (d) working length radiograph showing three separate distinct canals, (e and f) postoperative periapical radiographs

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After local anesthesia administration (2% lidocaine with 1:100,000 epinephrine) (Dentsply Maillefer, Ballaigues, Switzerland) and rubber dam isolation, access cavity was refined. Pulp chamber floor revealed two distinct orifices buccally and palatally. During enlargement and debridement of the canals, the presence of a third canal confirmed resulting in three-separated canals, two buccal – mesiobuccal (MB) and distobuccal (DB) and one palatal (P) [Figure 1]c. A final working length periapical radiograph showed all three separated canals [Figure 1]d.

All canals were cleaned and shaped using Profile 0.04 rotary system (Dentsply Maillefer, Ballaigues, Switzerland), up to size 40 for P canal, and 35 for MB and DB canals, and irrigated with 5.25% NaOCl. Final rinse was done with 17% EDTA followed by 5.25% NaOCl, with the aid of passive ultrasonic activation (Irrisafe tips, Acteon, Merignac, France) was performed. Obturation was carried out using continuous wave compaction technique with gutta-percha and AHplus sealer (Dentsply Maillefer, Ballaigues, Switzerland), and then the tooth was double-sealed with temporary filling material (Coltosol, Germany) and glass-ionomer cement (GC Corporation, Tokyo, Japan) [Figure 1]e and [Figure 1]f. Later, the patient was referred to the prosthetic department for definitive coronal restoration. The patient missed his 1-year recall appointment twice.

Case 2

A 39-year-old Saudi male patient with controlled hypertension Class II according to the American Society of Anesthesiologists (ASA), was referred from the Prosthodontics Department in King Saud University Dental Hospital to the Endodontics Department to evaluate multiple teeth for root canal retreatment before crowning. Clinically, the right maxillary first premolar (#14) was heavily restored with amalgam restoration. Tooth was not tender to percussion or palpation and all other clinical findings were within normal limits. Radiographic examination revealed inadequate root canal treatment done 9 years ago. The tooth is apparently three rooted having two buccal canals bifurcating in coronal third of the root. The MB canal was eventually missed from the previous treatment. Moreover, apical radiolucency related to the distal root and prefabricated post in the previously filled DB canal was evident [Figure 2]a and [Figure 2]b. Tooth #14 was diagnosed as previously treated with asymptomatic apical periodontitis.
Figure 2: Case 2: (a and b) Preoperative periapical radiographs of #14, (c) clinical photo of the access cavity showing the triangular settlement of the three canal orifices, (d) cone-beam computed tomography of axial sections showing the three distinct roots and canals mesiobuccal, distobuccal (arrow), and palatal, (e) periapical radiograph showing three canals negotiated to the full length, (f) clinical photo of access cavity after obturation, (g and h) postoperative periapical radiographs

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The tooth was isolated with rubber dam and access cavity was modified with a cut at the bucco-proximo angle from the entrance of the buccal canals to the cavosurface angle resulting in a cavity with a T-shaped outline as described by Balleri et al. [Figure 2]c.[18] Magnification revealed three orifices. The missed mesiobuccal canal was not negotiated to the full length easily. After removing the entire previous old filling, limited field of view CBCT was requested and marked clearly the three separated root canals with complete patency [Figure 2]d.

Working length was determined and the radiograph revealed three distinct canals, MB DB, and P, each continuing on its own pathway to the apex [Figure 2]e. Root canal treatment was performed in the same manner of case 1 [Figure 2]f, [Figure 2]g, [Figure 2]h. The patient was referred back to his prosthodontist for coronal restoration. The patient was asymptomatic on follow-up visit after 10 months and periapical radiograph showed healed apical radiolucency.

Case 3

A 34-year-old Saudi female was referred from the restorative clinics at King Saud University Dental Hospital to the Endodontic Clinics for evaluation and treatment before restorative phase. The patient's medical history was noncontributory. Tooth #14 was planned for endodontic retreatment. The tooth was endodontically treated 5 years ago and crowned by then. Clinical examination revealed no soft-tissue abnormalities; the probing depth was within normal measures, and it has responded normally to percussion and palpation tests. Preoperative radiographs showed widening of the periodontal ligament and inadequate root canal treatment for two canals. An ambiguous root anatomy was perceived and possible anatomic tooth variation was suspected [Figure 3]a and [Figure 3]b. The case was diagnosed as previously treated with asymptomatic apical periodontitis.
Figure 3: Case 3: (a and b) Preoperative radiographs of #14, (c) clinical photo of access cavity, (d) working length periapical radiograph, (e) postoperative periapical radiograph after obturation

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After crown removal and rubber dam isolation, old gutta-percha was removed and access was modified. Only two orifices were detected initially, one buccal and one palatal. A slightly larger size buccal orifice was noted, so extension of it was carried out. By exploring the buccal orifice with small-sized K-files (Dentsply Maillefer, Ballaigues, Switzerland), the third missed DB canal was detected. The exact location of the MB and DB canals was clarified by modifying the access to a T-shaped outline following Balleri et al. [Figure 3]c.[11],[18]

Working length of the canals was determined. Full length could not be reached in the mesiobuccal root due to a ledging from the previous treatment [Figure 3]d. Full endodontic treatment was carried out as previously done with case number 1 [Figure 3]e. Follow-up after 18 months manifested an asymptomatic tooth without any radiographic abnormalities.

Case 4

A 25-year-old Saudi male patient was referred from the Restorative Clinics at King Saud University Dental Hospital to the Endodontics Department for a number of root canal treatments. The patient was not aware of any medical problems. Tooth #24 has inadequate root canal treatment with defective temporary filling coronally. Nothing was significant during clinical examination. Normal alveolar bone was apparent radiographically. Three canals were obvious with a short filling from the previous treatment [Figure 4]a. Diagnosis of the tooth as previously treated with normal apical tissue was made.
Figure 4: Case 4: (a) Preoperative periapical radiograph, (b) clinical photo of access cavity, (c) clinical photo of access cavity after obturation, (d and e) postoperative periapical radiographs after obturation, (f and g) follow-up radiographs after 1 year of different angles showing no abnormalities

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After accessing the tooth, adjustment of the access clarified three distinct orifices [Figure 4] b. Treatment was performed following the same approach of the previously mentioned cases [Figure 4]c, [Figure 4]d, [Figure 4]e. One-year recall appointment revealed asymptomatic tooth with complete apical healing radiographically [Figure 4]f and [Figure 4]g.

  Discussion Top

Premolar teeth have been considered the most difficult to be endodontically treated, owing to the strong possibility of having supernumerary root canals.[14],[19] Failing to recognize the presence of a canal, leaving it untreated, has been shown to be one of the topmost causes for root canal treatment failures.[16] As additional third canal in maxillary first premolars is one of the most common variations in such teeth, anticipating its presence before initiation of therapy will greatly facilitate subsequent treatment. As prerequisites for successful endodontic treatment, attentive knowledge of the root canal anatomy with a meticulous radiographic and clinical evaluation before start of treatment are required.[3],[4],[8]

Visualization of the three canals in maxillary premolars on preoperative radiographs can often be difficult. The conventional periapical radiographs are two-dimensional images of a three-dimensional object and therefore may not be sufficient to give a complete picture of the internal root canal anatomy. However, alert inspection of these radiographs before starting is always essential for a general estimated view of the tooth anatomy and help suspecting if any difficulty or variation exists.[20] It is always recommended to have at least two horizontally angulated diagnostic radiographs for better evaluation and recognition of roots and root canals number.[21]

Sieraski et al. have suggested a general guideline for early identification of three-rooted maxillary premolars radiographically. Straight periapical radiographs showing the mesiodistal width of the mid-root image equal to or greater than the mesiodistal width of the crown image gives an indication that the tooth most likely has three roots.[11] A sudden narrowing or disappearing of the canal when studying the direct periapical exposure film renders a hint that the canal dividing at this point.[3] Moreover, tracing each individual root periodontal ligament space would be helpful.[22] Laying on the aforementioned guides, third root canal in the first case was conceived during the initial radiographic examination.

Careful examination of the floor of the pulp chambers is necessary for good access and successful clinical treatment.[11] Eccentric canal orifice is a clue for the presence of additional canal that the dentist should search for alongside the first one. When the floor of the chamber of the maxillary premolar is not aligned in its predicted buccopalatal relationship, the third canal should be suspected.[3],[18] Good management will be achieved if the presence of anatomical variation is early anticipated, by means of access cavity modifying if required and correct canals locating. Balleri et al. advocated the extension of the access mesiodistally along the buccal aspect resulting in a “T”-shaped access cavity.[11],[18] This modified preparation outline for the three-canalled maxillary premolars favors a good access to each of the two buccal canals, which was followed in all above-mentioned cases.

In the second and third retreatment cases, the asymmetry of the previously obturated canal orifices was apparent. Applying Krasner and Rankow s' symmetry laws, especially when unexpected atypical anatomy is anticipated helped in detecting the second buccal canal and confirmed its presence.[23] More recently, Beltes et al. indicated that none of the teeth displayed three separated orifices in the 56 three-rooted maxillary first premolar examined, although all exhibited two orifices initially.[10] These findings are also observed with our cases (1 and 3). In contrast, teeth of cases 2 and 4 exhibited two separated buccal orifices and one palatal orifice.

Bilateral occurrence of variations has been reported by Sabala et al. to be 60%.[24] In the second and fourth cases, the radiographs of the opposite side disclosed the presence of three-rooted maxillary first premolar [Figure 5]a, [Figure 5]b, [Figure 5]c. The dental history of prior-treated teeth should always be reviewed and interpreted carefully. As those previously treated with an anatomical abrasion could draw the attention in suspecting same variation in the contralateral tooth presently being considered for treatment.
Figure 5: Contralateral side of case number 2 showing a similar anatomical conformation (a) periapical radiograph, (b) axial section of cone-beam computed tomography, (c) periapical radiograph of the contralateral side of case number 4 showing a three-canaled premolar

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Interestingly, three of the presented cases were for male patients. It has been claimed that various factors could contribute to the root and root canal morphology aberration including gender. Recently, Ahmad and Alenezi reported a predilection of roots and root canals to be higher in males than females.[4] Male patients showed significantly greater number of roots and root canals compare to female patients among different populations.[15],[19],[25] On the other hand, a study among Saudi Arabian population found no statistical significant difference between male and female patients in number of root canals in maxillary first premolars.[8]

All cases have been treated under the dental operating microscope (Zeiss OPMI Pico, Carl Zeiss Surgical, Oberkochen, Germany). A huge step forward in the advancement of endodontics took place in the early 1990s, when the microscope was first introduced into this field. Both the practice of nonsurgical and surgical endodontics has been enhanced. The paramount importance of the operating microscope has been testified in greatly improving the visualization of the root canal complex internal anatomy and the clarity in locating additional canals.[26]

A prerequisite for successful endodontic treatment is the identification and treatment of all suspected root canals. A valuable addition to the endodontic's armamentarium is the CBCT, for consistently revealing exact number of roots and canals. Such technology can provide three-dimensional imaging, allowing better visualization and full appreciation of the root canal anatomy.[27] When suspecting extracanal and complex morphology, applying the CBCT has been recommended by the American Association of Endodontists and the American Academy of Oral and Maxillofacial Radiology (AAE and AAOMR) Joint Position Statement.[28] However, CBCT should only be considered when information has not been given sufficiently by the conventional periapical radiographs. As in the second case, it was applied to help in fully appreciating the root canal anatomy. Evaluation of missed canals with CBCT in such endodontic retreatments, adds to its precise location and complete treatment. Nonetheless, the benefits versus the risks should always be weighed and considered before deciding which diagnostic modality to apply.[29]

  Conclusion Top

This paper presents the management of four Saudi patients who presented with the uncommon anatomy of three root-canaled maxillary first premolars. One of the major causes for failure in endodontic treatment is incomplete obturation and unnoticed canals. Clinical thoroughness and early identification of aberrant tooth morphology assist refraining possible mishaps. Enhanced visualization with the aid of dental operating microscope also helped in increasing the efficiency of treatment.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their 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

Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endod Top 2005;10:3-29.  Back to cited text no. 1
Bellizzi R, Hartwell G. Radiographic evaluation of root canal anatomy ofin vivo endodontically treated maxillary premolars. J Endod 1985;11:37-9.  Back to cited text no. 2
Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 1984;58:589-99.  Back to cited text no. 3
Ahmad IA, Alenezi MA. Root and root canal morphology of maxillary first premolars: A Literature review and clinical considerations. J Endod 2016;42:861-72.  Back to cited text no. 4
Orban B, Mueler E. The development of the bifurcation of multirooted teeth. J Am Dent Assoc 1929;16:297-319.  Back to cited text no. 5
Awawdeh L, Abdullah H, Al-Qudah A. Root form and canal morphology of Jordanian maxillary first premolars. J Endod 2008;34:956-61.  Back to cited text no. 6
Atieh MA. Root and canal morphology of maxillary first premolars in a Saudi population. J Contemp Dent Pract 2008;9:46-53.  Back to cited text no. 7
Al-Nazhan S, Al-Daafas A, Al-Maflehi N. Radiographic investigation ofin vivo endodontically treated maxillary premolars in a Saudi Arabian sub-population. Saudi Endod J 2012;2:1-5.  Back to cited text no. 8
  [Full text]  
Belizzi R, Hartwell G. Evaluating the maxillary premolar with three canals for endodontic therapy. J Endod 1981;7:521-7.  Back to cited text no. 9
Beltes P, Kalaitzoglou ME, Kantilieraki E, Beltes C, Angelopoulos C 3-rooted maxillary first premolars: An ex vivo study of external and internal morphologies. J Endod 2017;43:1267-72.  Back to cited text no. 10
Sieraski SM, Taylor GN, Kohn RA. Identification and endodontic management of three-canalled maxillary premolars. J Endod 1989;15:29-32.  Back to cited text no. 11
Maibaum WW. Endodontic treatment of a “ridiculous” maxillary premolar: A case report. Gen Dent 1989;37:340-1.  Back to cited text no. 12
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. 13
Pécora JD, Saquy PC, Sousa Neto MD, Woelfel JB. Root form and canal anatomy of maxillary first premolars. Braz Dent J 1992;2:87-94.  Back to cited text no. 14
Rózyło TK, Miazek M, Rózyło-Kalinowska I, Burdan F. Morphology of root canals in adult premolar teeth. Folia Morphol (Warsz) 2008;67:280-5.  Back to cited text no. 15
Hoen MM, Pink FE. Contemporary endodontic retreatments: An analysis based on clinical treatment findings. J Endod 2002;28:834-6.  Back to cited text no. 16
Song M, Kim HC, Lee W, Kim E. Analysis of the cause of failure in nonsurgical endodontic treatment by microscopic inspection during endodontic microsurgery. J Endod 2011;37:1516-9.  Back to cited text no. 17
Balleri P, Gesi A, Ferrari M. Primer premolar superior com tres raices. Endod Pract 1997;3:13-5.  Back to cited text no. 18
Bürklein S, Heck R, Schäfer E. Evaluation of the root canal anatomy of maxillary and mandibular premolars in a selected German population using cone-beam computed tomographic data. J Endod 2017;43:1448-52.  Back to cited text no. 19
Patel S. New dimensions in endodontic imaging: Part 2. Cone beam computed tomography. Int Endod J 2009;42:463-75.  Back to cited text no. 20
Walton RE. Endodontic radiographic technics. Dent Radiogr Photogr 1973;46:51-9.  Back to cited text no. 21
Alenezi MA, Tarish MA, Al-Nazhan S. Cone-beam computed tomography of bilateral radiculous maxillary first premolars. Saudi Endod J 2016;6:153-6.  Back to cited text no. 22
  [Full text]  
Krasner P, Rankow HJ. Anatomy of the pulp-chamber floor. J Endod 2004;30:5-16.  Back to cited text no. 23
Sabala CL, Benenati FW, Neas BR. Bilateral root or root canal aberrations in a dental school patient population. J Endod 1994;20:38-42.  Back to cited text no. 24
Ok E, Altunsoy M, Nur BG, Aglarci OS, Çolak M, Güngör E, et al. Acone-beam computed tomography study of root canal morphology of maxillary and mandibular premolars in a Turkish population. Acta Odontol Scand 2014;72:701-6.  Back to cited text no. 25
Buhrley LJ, Barrows MJ, BeGole EA, Wenckus CS. Effect of magnification on locating the MB2 canal in maxillary molars. J Endod 2002;28:324-7.  Back to cited text no. 26
Patel S, Durack C, Abella F, Shemesh H, Roig M, Lemberg K, et al. Cone beam computed tomography in endodontics – A review. Int Endod J 2015;48:3-15.  Back to cited text no. 27
American Association of Endodontists, American Academy of Oral and Maxillofacial Radiology. Use of cone-beam computed tomography in endodontics joint position statement of the American Association of Endodontists and the American Academy of Oral and Maxillofacial Radiology. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2011;111:234-7.  Back to cited text no. 28
Ball RL, Barbizam JV, Cohenca N. Intraoperative endodontic applications of cone-beam computed tomography. J Endod 2013;39:548-57.  Back to cited text no. 29


  [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]


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