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Table of Contents
Year : 2022  |  Volume : 10  |  Issue : 2  |  Page : 118-120

Successful endodontic treatment of two cases of radix entomolaris in partially erupted mandibular third molars with 4 and 3 root canals, respectively

1 Department of Conservative Dentistry and Endodontics, K.M. Shah Dental College and Hospital, Sumandeep Vidhyapeeth, Vadodara, Gujarat, India
2 Department of Pediatrics and Neonatology, S.K.B.S Medical College and Hospital, Sumandeep Vidhyapeeth, Vadodara, Gujarat, India

Date of Submission26-Dec-2022
Date of Decision09-Feb-2023
Date of Acceptance16-Feb-2023
Date of Web Publication16-May-2023

Correspondence Address:
Dr. Ruchi Shah
Department of Conservative Dentistry and Endodontics, K.M. Shah Dental College and Hospital, Vadodara, Gujarat
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Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jihs.jihs_20_22

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Dentists encounter a variety of anatomical variations on a regular basis. In this situation, the mandibular third molars are not far away. Because of their most posterior placement and unexpected morphology, extraction frequently continues to be the preferred course of therapy. An extra distolingual root (radix entomolaris) poses a significant anatomical challenge and is also extremely uncommon. Therefore, one of the key requirements for a successful root canal procedure is the identification and management of the radix entomolaris. The purpose of this article is to describe how two cases of mandibular third molar with three roots and 4 root canals in the first case and 3 root canals in the second case were successfully managed endodontically.

Keywords: Additional third root, permanent mandibular third molar, radix entomolaris, three roots four canals

How to cite this article:
Shah R, Shah PP. Successful endodontic treatment of two cases of radix entomolaris in partially erupted mandibular third molars with 4 and 3 root canals, respectively. J Integr Health Sci 2022;10:118-20

How to cite this URL:
Shah R, Shah PP. Successful endodontic treatment of two cases of radix entomolaris in partially erupted mandibular third molars with 4 and 3 root canals, respectively. J Integr Health Sci [serial online] 2022 [cited 2023 Jun 2];10:118-20. Available from: https://www.jihs.in/text.asp?2022/10/2/118/377147

  Introduction Top

Permanent mandibular third molars often have two distinct mesial and distal morphological roots. However, there could be a variations in the roots number. Radix paramolaris (RP) is the name of a accessary third root that is situated mesiobuccally. Radix entomolaris (RE) is the name of a third root that is situated distolingually (RE). RE is more prevalent than RP globally. The third root's etiology in the mandibular molar is still unclear.

The root canal treatment of such tooth could be significantly impacted by an ignorance of the quantity, location, and morphology of the mandibular third molars, which could lead to significant failure of endodontic treatment.[1],[2]

A variation like this is typical of the mandibular first molar, uncommon in the mandibular third molar, and least common in the mandibular second molar. RE was most prevalent among the Mongolian race, which also includes Chinese, Taiwanese, and Koreans. It is yet regarded as an atypical or dysmorphic root morphology because it is uncommon among Caucasians (3.4%–4.2%).[2] In India, 24% prevalence of radix entomolaris have been seen. Comparing the mandibular third molar to other teeth that may have one or four roots, there are significant anatomical and morphological differences. The additional roots in the mandibular third molar have only recently been discovered in vitro using the clearing procedure and very few case of endodontic treatment have been reported.[3]

From the point of endodontic success, the diagnosis and treatment of RE are of utmost importance. These case reports emphasize the infrequent occurrence of radix in mandibular third molars, its successful care and difficulties while treating, and the need to try to see the invisible.

  Case Reports Top

Case 1

A 25-year-old male patient reported having unprovoked pain in his right lower back region of the jaw for the previous week. Deep cavities had exposed the pulp of partially erupted third molar. A clinical and radiographic examination showed that the tooth was symptomatic from vertical pressure and vestibular tenderness was also observed. The pulp vitality tests (cold and electric pulp tests) showed negative responses. After radiographic assessment of periapical lesion, the diagnosis of phoenix abscess was verified [Figure 1]a. Using radiography, another root was discovered. A second radiograph was taken with the identical lingual position opposite the buccal. Following the patient's agreement, inferior alveolar nerve block was administered with local anesthetic (2% lignocaine with 1:100,000 epinephrine, Lignospan Standard, Septodent). As tooth was partially erupted rubber dam application was very difficult to place. The typical access opening had to be redefined in order to find an additional canal. Four root canal orifices were found after rigorous observation and evaluation with operational loupes 3.5 (Zumax). The mesiobuccal, mesiolingual, distobuccal (DB), and DL root canal orifices were all discovered simultaneously [Figure 1]b. The coronal walls caries were eliminated, and the working length was determined by radiography and an apex locator (Root ZX, J. Morita Inc.). All canals were prepared till X1 Protaper Next (Dentsply Maillefer, Switzerland) for chemomechanical preparation, which included extensive use of 3% sodium hypochlorite and 17% ethylenediaminetetraacetic acid. Double antibiotic paste was placed as intracanal medication, and then Orafil G was used to temporize. After 2 weeks, the patient was called back.
Figure 1: (a) Preoperative radiograph was partially erupted Mandibular third molar with deep caries involving pulp and periapical lesion, (b) Working length radiograph showing 4 canals MB, ML, DB, DL, (c) Obturation and post endodontic restoration following chemomechanical preparation. MB: Mesiobuccal, ML: Mesiolingual, DB: Distobuccal, DL: Distolingual

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After 2 weeks, the patient returned, completely asymptomatic. The temporary infill was eliminated, and the canals were then irrigated and dried using paper points. A radiograph was taken after the relevant gutta-percha sites were positioned. After finishing the root canal obturation with 20.06 GP (Denstply, Endosure) and resin sealer (AH Plus), nanohybrid composite was used to complete the postendodontic permanent restoration [Figure 1]c.

Case 2

A 27-year-old female patient reported with dull aching pain with respect to left lower back tooth region. On examination, deep caries were seen. Tooth was mild tender on percussion. Vestibular tenderness was present. After radiographic interpretation of a radiolucent lesion surrounding the apex, the diagnosis of chronic periapical abscess was made [Figure 2]a. After obtaining proper consent from the patient, inferior alveolar nerve block with local anesthesia was administered and access opening was performed. Three root canal orifices were located and cleaned which were mesial, DB and DL [Figure 2]b, with hybrid technique till F1 protaper files (Dentsply Maillefer, Switzerland) with copious irrigation. After proper drying the canal, master cones tug back was checked along with radiographs followed by obturation [Figure 2]c and [Figure 2]d.
Figure 2: (a) Preoperative radiograph was partially erupted Mandibular third molar with deep caries involving pulp and periapical lesion, (b) Working length radiograph showing 3 canals MB, DB, DL, (c) Master cone radiograph, (d) Obturation and post endodontic restoration following chemomechanical preparation. MB: Mesiobuccal, DB: Distobuccal, DL: Distolingual

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  Discussion Top

Due to their most posterior placement, uncertain internal anatomy, strange occlusal anatomy, and abnormal eruption patterns, third molar endodontic treatment is regarded as a difficult procedure.[4] Although third molar excision is frequently the preferred course of action, there are some clinical circumstances where keeping these teeth is necessary. Where second molars are missing, third molars may act as an abutment for a permanent or removable partial denture. The principle of endodontics is also focused on preserving every single functional part of the tooth arch. Third molars can have extra roots (RE), curved roots, bayonet roots, fused canals, C-shaped canals, dilacerations, and other morphological variants. RE's precise cause is still a mystery. RE's precise cause is still a mystery.[5] According to some authors, it might be caused by an atavistic gene or a disruption in odontogenesis. The incidence varies amongst populations and ranges from 5% to 30%.[6] A minimum of two diagnostic radiographs employing the buccal object rule are required for a proper diagnosis. Sometimes RE can even be detected by the existence of an additional cusp.

Following are a few of the frequent issues that arise during the treatment of RE in the mandibular third molar:

  • Radiographic interpretation challenges
  • Being unable to find the fourth canal due to a lack of space
  • Inferior alveolar nerve proximity
  • Confusion in determining working length
  • Installation of the rubber dam is difficult.

In addition to these challenges, practitioners are vulnerable to making various iatrogenic mistakes such straightening a root canal, which can lead to loss of working length, ledge formation, zipping, transporting, or even perforation, and instrument separation due to a restricted mouth opening. Therefore, before beginning the therapy for the mandibular third molar, these considerations should be taken into consideration.[7],[8]

  Conclusion Top

Although RE in the third molar of the mandible is extremely uncommon, it was nevertheless possible to identify it using radiographic methods and improved magnification aids. The successful endodontic therapy of RE in the mandibular third molar is not well documented in the literature.

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 initial s will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed


Sumandeep Vidhyapeeth, Vadodara.

Financial support and sponsorship


Conflicts of interest

There are no conflicts of interest.

  References Top

Aly Ahmed HM. Management of third molar teeth from an endodontic perspective. Eur J Gen Dent 2012;1:148-60.  Back to cited text no. 1
  [Full text]  
Calberson FL, De Moor RJ, Deroose CA. The radix entomolaris and paramolaris: Clinical approach in endodontics. J Endod 2007;33:58-63.  Back to cited text no. 2
Mohan S, Thakur J. Prevalence of radix entomolaris in India and its comparison with the rest of the world. Minerva Dent Oral Sci 2022;71:117-22.  Back to cited text no. 3
Arora S, Gill GS, Setia P, Abdulla AM, Sivadas G, Vedam V. Endodontic management of a severely dilacerated mandibular third molar: Case report and clinical considerations. Case Rep Dent 2018;2018:7594147.  Back to cited text no. 4
Garg AK, Bhardwaj A, Mantri VR, Agrawal N. Endodontic management of mesiobuccal-2 canal in four-rooted and five-canalled mandibular third molar. J Contemp Dent Pract 2014;15:363-6.  Back to cited text no. 5
Sinha DJ, Sinha AA. An endodontic management of mandibular third molar with five root canals. Saudi Endod J 2014;4:36-9.  Back to cited text no. 6
  [Full text]  
Sidow SJ, West LA, Liewehr FR, Loushine RJ. Root canal morphology of human maxillary and mandibular third molars. J Endod 2000;26:675-8.  Back to cited text no. 7
Guerisoli DM, de Souza RA, de Sousa Neto MD, Silva RG, Pécora JD. External and internal anatomy of third molars. Braz Dent J 1998;9:91-4.  Back to cited text no. 8


  [Figure 1], [Figure 2]


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