Background/Aim: To determine the prevalence of single-rooted mandibular second molars in a Greek population and examine their internal morphology with the aid of intraoral periapical radiography.
Material and Methods: Clinical records of 531 root-canal treated permanent single-rooted mandibular second molars were collected from the Postgraduate Clinic of the Department of Endodontology, Dental School, Aristotle University of Thessaloniki, Greece and from private dental clinics in the same city. The clinical records, along with the radiographic examination, were evaluated to determine the overall frequency of single-rooted mandibular second molars together with the number of root canals and their course. The root canals were categorized using Vertucci’s classification with the addition of 3 further types where appropriate.
Results: Out of 531 mandibular second molars; 102 (19.2%) presented a single root; 427 (80.4%) presented two roots; 2 (0.4%) presented three roots. In a total of 102 single-rooted mandibular second molars 31 (30.3%) presented with Type I, 18 (17.6%) with Type II, 14 (13.7%) with Type IV, 7 (7%) with 3 additional root canal types and 32 (31.4%) with a C-shaped root canal system.
Conclusions: One out five mandibular second molars was single-rooted in a Greek population. The internal morphology of these teeth can be very complex with regard to the numbers and courses of root canals.
1. Vertucci FJ. Root canal morphology and its relationship to endodontic procedures. Endod Topics, 2005;10:3–29.
2. Kim SY, Kim BS, Kim Y. Mandibular second molar root canal morphology and variants in a Korean subpopulation. Int Endod J, 2016;49:136–144.
3. Celikten B, Tufenkci P, Aksoy U, Kalender A, Kermeoglu F, Dabaj P, Orhan K. Cone beam CT evaluation of mandibular molar root canal morphology in a Turkish Cypriot population. Clin Oral Investig, 2016;20:2221–2226.
4. Neelakantan P, Subbarao C, Subbarao CV, Ravindranath M. Root and canal morphology of mandibular second molars in an Indian population. J Endod, 2010;36:1319–1322.
5. 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;18:737–744.
6. Gulabivala K, Aung TH, Alavi A, Ng YL. Root and canal morphology of Burmese mandibular molars. Int Endod J, 2001;34:359–370.
7. Gulabivala K, Opasanon A, Ng YL, Alavi A. Root and canal morphology of Thai mandibular molars. Int Endod J, 2002;35:478–485.
8. Al-Qudah AA, Awawdeh LA. Root and canal morphology of mandibular first and second molar teeth in a jordanian population. Int Endod J, 2009;42:775–784.
9. Ahmed HA, Abu-Bakr NH, Yahia NA, Ibrahim YE. Root and canal morphology of permanent mandibular molars in a Sudanese population. Int Endod J, 2007;40:766–771.
10. Peiris R, Takahashi M, Sasaki K, Kanazawa E. Root and canal morphology of permanent mandibular molars in a Sri Lankan population. Odontology, 2007;95:16–23.
11. 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;50:9–13.
12. Zhang R, Wang H, Tian YY, Yu X, Hu T, Dummer PMH. Use of cone-beam computed tomography to evaluate root and canal morphology of mandibular molars in Chinese individuals. Int Endod J, 2011;44:990–999.
13. Silva EJNL, Nejaim Y, Silva AV, Haiter-Neto F, Cohenca N. Evaluation of root canal configuration of mandibular molars in a Brazilian population by using cone-beam computed tomography: An in vivo study. J Endod, 2013;39:849–852.
14. Nur BG, Ok E, Altunsoy M, Aglarci OS, Colak M, Gungor E. Evaluation of the root and canal morphology of mandibular permanent molars in a south-eastern Turkish population using cone-beam computed tomography. Eur J Dent, 2014;8:154–159.
15. Torres A, Jacobs R, Lambrechts P, Brizuela C, Cabrera C, Concha G et al. Characterization of mandibular molar root and canal morphology using cone beam computed tomography and its variability in Belgian and Chilean population samples. Imaging Sci Dent, 2015;45:95–101.
16. Akhlaghi NM, Abbas FM, Mohammadi M, Shamlo MRK, Radmehr O, Kaviani R et al. Radicular anatomy of permanent mandibular second molars in an Iranian population: A preliminary study. Dent Res J (Isfahan), 2016;13:362–366.
17. Vertucci FJ. Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol, 1984;58:589–599.
18. Fan W, Fan B, Gutmann JL, Fan M. Identification of a C-shaped canal system in mandibular second molars-Part III: Anatomic features revealed by digital subtraction radiography. J Endod, 2008;34:1187–1190.
19. Fan B, Cheung GSP, Fan M, Gutmann JL, Fan W. C-shaped canal system in mandibular second molars: Part II-Radiographic features. J Endod, 2004;30:904–908.
20. Kato A, Ziegler A, Higuchi N, Nakata K, Nakamura H, Ohno N. Aetiology, incidence and morphology of the C-shaped root canal system and its impact on clinical endodontics. Int Endod J, 2014;47:1012–1033.
21. Von Zuben M, Martins JNR, Berti L, Cassim I, Flynn D, Gonzalez JA et al. Worldwide prevalence of mandibular second molar C-shaped morphologies evaluated by cone-beam computed tomography. J Endod, 2017;43:1442–1447.
22. Lambrianidis T, Lyroudia K, Pandelidou O, Nicolaou A. Evaluation of periapical radiographs in the recongnition of C-shaped mandibular second molars. Int Endod J, 2001;34:458–462.