The Prevalence of Radix Paramolaris and Entomolaris in Mandibular Molar Teeth: A Retrospective Study

Abstract

Abstract Objective: The aim of this study is to analyze the frequency of radix paramolaris (RP) and radix entomolaris (RE) in the first and second molars using cone beam computed tomography (CBCT). Materials and Methods: The CBCT images of a total of 400 patients at the ages of 14 to 66 were included in the study. On the images that were included, two maxillofacial radiologists simultaneously examined the presence of radix paramolaris and radix entomolaris by using axial CBCT cross-sections from the pulpal chamber towards the apical. Results: At least one RE or RP was observed in 36 of the 400 patients (9%). A total of 20 RPs (1.25%) were observed, including 2 bilateral and 16 unilateral cases. A total of 38 REs (2.38%) were observed, including 11 bilateral and 16 unilateral cases. There was at least one RE or RP in 16 of the 149 male patients (10.7%) and in 20 of the 251 female patients (8%). Conclusion: Consequently, while the prevalence and types of third root variations differ between different populations, RE is seen more frequently in mandibular first molar teeth, and RP is seen more frequently in mandibular second molar teeth. No significant relationship could be found between sex and the prevalence of third root variations in mandibular molar teeth images included in this study. No significant difference was found between the right and left sides as the localizations of RP and RE in terms of prevalence. Keywords: Radix entomolaris; Radix paramolaris; Root canal morphology; Cone-beam CT; Mandibular molar

Keywords

• radix entomolaris
• radix paramolaris
• root canal morphology
• cone-beam CT
• mandibular molar

References

1. REFERENCES: 1. Fava LR. Root canal treatment in an unusual maxillary first molar: a case report. Case Reports Int Endod J 2001 Dec;34(8):649-53.
2. 2. Rahimi S, Shahi S, Lotfi M, Zand V, Abdolrahimi M, Es'haghi R. Root canal configuration and the prevalence of C-shaped canals in mandibular second molars in an Iranian population. J Oral Sci. 2008 Mar;50(1):9-13.
3. 3. Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg Oral Med Oral Pathol. 1974 May;37(5):762-72.
4. 4. Burns RC, Herbranson EJ. Tooth morphology and access cavity preparation. In: Cohen S, Burns RC, editors. Pathways of the Pulp. 8th edition. St Louis, Mo, USA: Mosby; 2002. pp. 173–229.
5. 5. Barker BC, Parsons KC, Mills PR, Williams GL. Anatomy of root canals. III. Permanent mandibular molars. Aust Dent J. 1974 Dec;19(6):408-13.
6. 6. Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol. 1984 Nov;58(5):589-99.
7. 7. Nagaveni N, Umashankara K. Radix entomolaris and paramolaris in children: A review of the literature. J Indian Soc Pedod Prev Dent 2012;30:94-102.
8. 8. Tu MG, Huang HL, Hsue SS, Hsu JT, Chen SY, Jou MJ, Tsai CC. Detection of permanent three-rooted mandibular first molars by cone-beam computed tomography imaging in Taiwanese individuals. J Endod. 2009 Apr;35(4):503-7.

9. 9. Kottoor J, Albuquerque DV, Velmurugan N, Sumitha M. Four-Rooted Mandibular First Molar with an Unusual Developmental Root Fusion Line: A Case Report. Case Rep Dent. (2012: 237302.)
10. 10. Rajasekhara S, Sharath Chandra S, Parthasarathy LB. Cone beam computed tomography evaluation and endodontic management of permanent mandibular second molar with four roots: A rare case report and literature review J Conserv Dent. 2014 Jul; 17(4): 385-8.
11. 11. Slowey RR. Radiographic aids in the detection of extra root canals. Oral Surg Oral Med Oral Pathol. 1974 May;37(5):762-72.
12. 12. White SC, Pharoah MJ. Oral Radiology: Principles and Interpretation. St. Louis, Mo: Mosby/Elsevier, 2009.
13. 13. Gupta A, Duhan J, Wadhwa J. Prevalence of three rooted permanent mandibular first molars in Haryana (North Indian) Population. Contemp Clin Dent 2017;8:38-41.
14. 14. Rahimi S, Mokhtari H, Ranjkesh B, et al. Prevalence of Extra Roots in Permanent Mandibular First Molars in Iranian Population: A CBCT Analysis. Iran Endod J 2017;12:70-73.
15. 15. Kuzekanani M, Najafipour R. Prevalence and distribution of radix paramolaris in the mandibular first and second molars of an Iranian Population. J Int Soc Prev Commun Dent 2018;8:240-244.
16. 16. Agarwal M, Trivedi H, Mathur M, Goel D, Mittal S. The radix entomolaris and radix paramolaris: an endodontic challenge. J Contemp Dent Pract. 2014 Jul 1;15(4):496-9.
17. 17. Ahmetoğlu F, Altun O, Şimşek N, Ocak MS, Dedeoğlu N. Türkiye’nin doğu bölgesi nüfusundaki mandibular molar dişlerin kök ve kanal yapılarının konik ışınlı bilgisayarlı tomografi ile değerlendirilmesi. Cumhuriyet Dent J 2014;17:223-234.
18. 18. Demirbuga S, Sekerci AE, Dinçer AN, Cayabatmaz M, Zorba YO. Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular first and second molars in Turkish individuals. Med Oral Patol Oral Cir Bucal 2013;18:e737-44.
19. 19. Miloglu O, Arslan H, Barutcigil C, Cantekin K. Evaluating root and canal configuration of mandibular first molars with cone beam computed tomography in a Turkish population. J Dent Sci 2013;8:80-86.
20. 20. Loh HS. Incidence and features of three-rooted permanent mandibular molars. Aust Dent J 1990;35:434-437.
21. 21. Omer OE, Al Shalabi RM, Jennings M, Glennon J, Claffey NM. A comparison between clearing and radiographic techniques in the study of the root-canal anatomy of maxillary first and second molars. Int Endod J 2004;37:291-296.
22. 22. Cotton TP, Geisler TM, Holden DT, Schwartz SA, Schindler WG. Endodontic applications of cone-beam volumetric tomography. J Endod. septiembre de 2007;33(9):1121–32.
23. 23. Souza-Flamini LE, Leoni GB, Chaves JF, Versiani MA, Cruz-Filho AM, Pécora JD, Sousa-Neto MD. The radix entomolaris and paramolaris: a micro-computed tomographic study of 3-rooted mandibular first molars. J Endod. 2014 Oct;40(10):1616-21.
24. 24. Shemesh A, Levin A, Katzenell V, Ben Itzhak J, Levinson O, Zini A, Solomonov M. Prevalence of 3- and 4-rooted first and second mandibular molars in the Israeli population. J Endod. 2015 Mar;41(3):338-42.
25. 25. Yew SC, Chan K. A retrospective study of endodontically treated mandibular first molars in a Chinese population. J Endod. 1993 Sep;19(9):471-3.
26. 26. Steelman R. Incidence of an accessory distal root on mandibular first permanent molars in Hispanic children. ASDC J Dent Child. 1986 Mar-Apr;53(2):122-3. 
27. 27. Suyambukesan S, Perumal GL. Radiographic detection of additional root on mandibular molars in Malaysian population a prevalence study. JRID, 2013(3): 31–38.
28. 28. De Moor RJ, Deroose CA, Calberson FL. The radix entomolaris in mandibular first molars: An endodontic challenge. Int Endod J. 2004;37:789–99.
29. 29. Calberson FL, De Moor RJ, Deroose CA. The radix entomolaris and paramolaris: Clinical approach in endodontics. J Endod. 2007;33:58–63.
30. 30. Felsypremila G, Vinothkumar TS, Kandaswamy D. Anatomic symmetry of root and root canal morphology of posterior teeth in Indian subpopulation using cone beam computed tomography: A retrospective study. Eur J Dent. 2015 Oct-Dec;9(4):500-507.
31. 31. Martins JNR, Marques D, Mata A, Caramês J. Root and root canal morphology of the permanent dentition in a Caucasian population: a cone-beam computed tomography study. Int Endod J. 2017 Nov;50(11):1013-1026.
32. 32. Carlsen O, Alexandersen V. Radix paramolaris in permanent mandibular molars: identification and morphology. Scand J Dent Res. 1991 Jun;99(3):189-95.
33. 33. Sperber GH, Moreau JL. Study of the number of roots and canals in Senegalese first permanent mandibular molars. Int Endod J. 1998 Mar;31(2):117-22. 
34. 34. Różyło TK, Piskórz MJ, Różyło-Kalinowska IK. Radiographic appearance and clinical implications of the presence of radix entomolaris and radix paramolaris. Folia Morphol (Warsz). 2014 Nov;73(4):449-54.
35. 35. Walker RT. Root form and canal anatomy of mandibular first molars in a southern Chinese population. Endod Dent Traumatol. 1988;4(1):19-22.
36. 36. Gulabivala K, Aung TH, Alavi A, Ng YL. Root and canal morphology of Burmese mandibular molars. Int Endod J. 2001;34(5):359-70.
37. 37. Tu MG, Tsai CC, Jou MJ, Chen WL, Chang YF, Chen SY, Cheng HW. Prevalence of three-rooted mandibular first molars among Taiwanese individuals. J Endod. 2007;33(10):1163-6.