Keywords
radix entomolaris
radix paramolaris
Abstract
Introduction: Permanent mandibular first and second molars may display extra roots namely radix entomolaris and radix paramolaris which may have implications in endodontic treatment outcome, if missed.
Objective: To evaluate the occurrence of extra roots in permanent mandibular first and second molars in a sample of Nepalese population.
Methods: This analytical cross-sectional study was done at Dhulikhel hospital. Convenience sampling technique was utilised for data collection of 773 CBCT images. Images from June 2018 to June 2020 were retrospectively screened for presence of fully erupted bilateral mandibular first and second molars. Presence of extra roots were recorded and laterality, gender, and racial variations were analysed by Fisher’s exact test and Chi-square test using SPSS v.20.
Results: For mandibular first molars, out of 517 patients, 65 (11.38%) had radix entomolaris: 38 (13.2%) female and 27 (9.54%) male. Among 38 females; occurrence was 21 (7.3%) bilateral, 16 (5.56%) unilateral right and 1 (0.34%) unilateral left side. Likewise, among 27 males, the occurrence was 15 (5.3%) bilateral, 6 (2.1%) unilateral right and 6 (2.1%) unilateral left side. Regarding races, 50 (14.6%) were Mongoloids and 15 (6.6%) were Aryans. No radix paramolaris was found in mandibular first molars. For mandibular second molars, out of 623 patients, radix entomolaris and paramolaris were observed in 0.8% and 0.48% respectively.
Conclusion: The overall occurrence of radix entomolaris in mandibular first and second molars was found to be 11.38% and 0.8%, respectively. Practitioners should be aware of these unusual variations to avoid iatrogenic mishap due to missed canal.
References
Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol. 1984 Nov 1;58(5):589-99.
Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endod Topics. 2005 Mar;10(1):3-29.
Bolk L. Comments on root variations in the human lower molar. J Morphol Anthropol. 1915 Jan 1;17(3):605-10.
Calberson FL, De Moor RJ, Deroose CA. The radix entomolaris and paramolaris: Clinical approach in endodontics. J Endod. 2007 Jan 1;33(1):58-63.
Sperber GH, Moreau JL. Study of the number of roots and canals in senegalese first permanent mandibular molars. Int Endod J. 1998 Mar 1;31(2):117-22.
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;50(1):9-13.
Jayasinghe RD, Li TK. Three-rooted first permanent mandibular molars in a hong kong chinese population: A computed tomographic study. Hong Kong Dent J. 2007;4(2):90-3.
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 Oct 1;33(10):1163-6.
Sabala CL, Benenati FW, Neas BR. Bilateral root or root canal aberrations in a dental school patient population. J Endod. 1994 Jan 1;20(1):38-42.
De Moor RJ, Deroose CA, Calberson FL. The radix entomolaris in mandibular first molars: an endodontic challenge. Int Endod J. 2004 Nov;37(11):789-99.
Gulabivala K, Aung TH, Alavi A, Ng YL. Root and canal morphology of burmese mandibular molars. Int Endod J. 2001 Jul;34(5):359-70.
Gulabivala K, Opasanon A, Ng YL, Alavi A. Root and canal morphology of thai mandibular molars. Int Endod J. 2002 Jan;35(1):56-62.
Yew SC, Chan K. A retrospective study of endodontically treated mandibular first molars in a chinese population. J Endod. 1993 Sep 1;19(9):471-3.
Segura-Egea JJ, Jiménez-Pinzón A, Ríos-Santos JV. Endodontic therapy in a 3-rooted mandibular first molar: Importance of a thorough radiographic examination. J Can Dent Assoc. 2002 Oct 1;68(9):541-5.
Garg D, Kapoor D. Prevalence of radix entomolaris in population of central region of Nepal: A radiographic study. IP Int J Maxillofac Imaging. 2017 Jun 15;3(2):44-6.
Tripathi R, Nepal M, Gautam V, Sah R, Shrestha K, Thapa S. Prevalence of root canal morphology of mandibular molar in western nepalese population: A cross-sectional study. J Univers Coll Med Sci. 2020 Jul 3;8(1):38-41.
Schäfer E, Breuer D, Janzen S. The prevalence of three-rooted mandibular permanent first molars in a german population. J Endod. 2009 Feb 1;35(2):202-5.
Garg AK, Tewari RK, Kumar A, Hashmi SH, Agrawal N, Mishra SK. Prevalence of three-rooted mandibular permanent first molars among the indian population. J Endod. 2010 Aug 1;36(8):1302-6.
Song JS, Choi HJ, Jung IY, Jung HS, Kim SO. The prevalence and morphologic classification of distolingual roots in the mandibular molars in a korean population. J Endod. 2010 Apr 1;36(4):653-7.
Garg AK, Tewari RK, Agrawal N. Prevalence of three-rooted mandibular first molars among indians using SCT. Int J Dent. 2013 Jan 1;20(3):1-6.
Loh HS. Incidence and features of three-rooted permanent mandibular molars. Aust Dent J. 1990 Oct;35(5):434-7.
Visser JB. Contribution to the knowledge of human dental root forms. Rotting. 1948;29:49-72.
Carlsen O, Alexandersen V. Radix paramolaris in permanent mandibular molars: Identification and morphology. Eur J Oral Sci. 1991 Jun;99(3):189-95.
Onda S, Minemura R, Masaki T, Funatsu S. Shape and number of the roots of the permanent molar teeth. Bull Tokyo Dental Coll. 1989 Nov 1;30(4):221-31.
Tratman EK. Three rooted lower molars in man and their racial distribution. Br Dent J. 1938;64:264-74.