Abstract
Objectives
The purpose of this study was to evaluate the prevalence of three-rooted permanent mandibular first molars (PMFMs) with four canals and their morphological characteristics among a Korean population from using cone-beam computed tomography scans (CBCTs).
Materials and methods
Among the 705 CBCTs screened, 472 patient cases possessing at least one PMFM were identified. A total of 780 PMFMs were evaluated in axial section series to determine the number of roots and canals. The incidences of three-rooted PMFMs were compared with regard to gender and location. For distal root(s) with two canals, inter-orifice distances (IOD) between distobuccal and distolingual canals were measured at pulpal floor and furcation levels. The difference of IOD between males and females was also analyzed using chi-square tests.
Results
Among the 472 CBCTs of 225 females and 247 males, 84 females and 107 males were found to have at least one three-rooted PMFM. Among the 780 PMFMs, 191 PMFMs (24.5%, 89 of 397 left and 102 of 383 right) were found to have three roots. The prevalence of distal root(s) with two canals was 34.2% (267 of 780). From the molars with two distal canals, the mean IOD between distobuccal and distolingual canals at the pulpal floor level was 3.1 mm in males and 2.9 mm in females (p = 0.0428).
Conclusions
The occurrence of three-rooted PMFMs among a Korean population was 24.5% and was higher than other countries and ethnicities. Understanding the prevalence of PMFMs with a distolingual root and/or canal in a Korean population and the IOD between distobuccal and distolingual canals may be useful for successful endodontic treatments.
Clinical relevance
Acknowledgment of potential incidence of three-rooted permanent mandibular first molars with four canals and the distance between two distal canals may increase the success rate of root canal treatment by reducing the missing canal untreated.
Similar content being viewed by others
References
Calberson FL, De Moor RJ, Deroose CA (2007) The radix entomolaris and paramolaris: clinical approach in endodontics. J Endod 33:58–63
De Moor RJ, Deroose CA, Calberson FL (2004) The radix entomolaris in mandibular first molars: an endodontic challenge. Int Endod J 37:789–799
Vertucci FJ (1984) Root canal anatomy of the human permanent teeth. Oral Surg Oral Med Oral Pathol 58:589–599
Carlsen O, Alexandersen V (1990) Radix entomolaris: identification and morphology. Scan J Dent Res 98:163–173
Tu MG, Tsai CC, Jou MJ, Chen WL, Chang YF, Chen SY, Cheng HW (2007) Prevalence of three-rooted mandibular first molars among Taiwanese individuals. J Endod 33:1163–1166
Ferraz JAB, Pécora JD (1992) Three-rooted mandibular molars in patients of Mongolian, Caucasian and Negro origin. Braz Dent J 3:113–117
Huang RY, Lin CD, Lee MS, Yen CL, Shen EC, Chiang CY, Chiu HC, Fu E (2007) Mandibular disto-lingual root: a consideration in periodontal therapy. J Periodontol 78:1485–1490
Skidmore AE, Bjorndahl AM (1971) Root canal morphology of the human mandibular first molar. Oral Surg Oral Med Oral Pathol 32:778–784
Song JS, Choi HJ, Jung IY, Jung HS, Kim SO (2010) The prevalence and morphologic classification of distolingual roots in the mandibular molars in a Korean population. J Endod 36:653–657
Schäfer E, Breuer D, Janzen S (2009) The prevalence of three-rooted mandibular permanent first molars in a German population. J Endod 35:202–205
Gulabivala K, Opasanon A, Ng YL, Alavi A (2002) Root canal morphology of Thai mandibular molars. Int Endod J 35:56–62
Walker RT (1988) Root form and canal anatomy of mandibular first molars in a southern Chinese population. Dent Traumatol 4:19–22
Curzon MEJ (1973) Three-rooted mandibular permanent molars in English Caucasians. J Dent Res 52:181
Loh HS (1990) Incidence and features of three-rooted permanent mandibular molars. Aust Dent J 35:434–437
Matherne RP, Angelopoulos C, Kulild JC, Tira D (2008) Use of cone-beam computed tomography to identify root canal systems in vitro. J Endod 34:87–89
Nair MK, Nair UP (2007) Digital and advanced imaging in endodontics: a review. J Endod 33:1–6
Peck JL, Sameshima GT, Miller A, Worth P, Hatcher DC (2007) Mesiodistal root angulation using panoramic and cone beam CT. Angle Orthodont 77:206–213
Taylor C, Geisler TM, Holden DT, Schwartz SA, Schinler WG (2007) Endodontic applications of cone-beam volumetric tomography. J Endod 33:1121–1132
Peters OA, Laib A, Rüegsegger P, Barbakow F (2000) Three-dimensional analysis of root canal geometry by high-resolution computed tomography. J Dent Res 79:1405–1409
Jung M, Lommel D, Klimek J (2005) The imaging of root canal obturation using micro-CT. Int Endod J 38:617–626
Gu Y, Lu Q, Wang H, Ding Y, Wang P, Ni L (2010) Root-canal morphology of permanent three-rooted mandibular first molars—part I: pulp floor and root canal system. J Endod 36:990–994
Sjögren U, Figdor D, Persson S, Sundqvist G (1997) Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis. Int Endod J 30:297–306
Sundqvist G, Figdor D, Persson S, Sjögren U (1998) Microbiologic analysis of teeth with failed endodontic treatment and the outcome of conservative re-treatment. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 85:86–93
Siren EK, Haapasalo MP, Ranta K, Salmi P, Kerosuo EN (1997) Microbiological findings and clinical treatment procedures in endodontic cases selected for microbiological investigation. Int Endod J 30:91–95
Molander A, Reit C, Dahlén G, Kvist T (1998) Microbiological status of root-filled teeth with apical periodontitis. Int Endod J 31:1–7
Jones AW (1980) The incidence of the three-rooted first permanent molar in Malay people. Singapore Dent J 5:15–17
Walker RT, Quackenbush LE (1985) Three-rooted first permanent molars in Hong-Kong Chinese. Br Dent J 159:298–299
Younes SA, al-Shammery AR, el-Angbawi MF (1990) Three-rooted permanent mandibular first molars of Asian and black groups in the Middle East. Oral Surg Oral Med Oral Pathol 69:102–105
Somogyi-Csizmazia W, Simons AJ (1971) Three-rooted mandibular first permanent molars in Alberta Indian children. J Can Dent Assoc (Tor) 37:105–106
Steelman R (1986) Incidence of an accessory distal root on mandibular first permanent molars in Hispanic children. ASDC J Dent Child 53:122–123
Gulabivala K, Aung TH, Alavi A, Ng YL (2001) Root canal morphology of Burmese mandibular molars. Int Endod J 34:359–370
Schwartz GT, Dean MC (2005) Sexual dimorphism in modern human permanent teeth. Am J Phys Anthropol 128:312–317
Haralabakis NB, Sifakakis I, Papagrigorakis M, Papadakis G (2006) The correlation of sexual dimorphism in tooth size and arch form. World J Orthod 7:254–260
Sert S, Bayirli GS (2004) Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population. J Endod 30:391–398
Chen G, Yao H, Tong C (2009) Investigation of the root canal configuration of mandibular first molars in a Taiwan Chinese population. Int Endod J 42:1044–1049
Al-Nazhan S (1999) Incidence of four canals in root-canal treated mandibular first molars in a Saudi Arabian subpopulation. Int Endod J 32:49–52
Al-Qudah AA, Awawdeh LA (2009) Root and canal morphology of mandibular first and second molar teeth in a Jordanian population. Int Endod J 42:775–784
Acknowledgments
The authors thank Dr. P-B Park for her dedicated research support. The authors declare that they have no conflict of interest.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Jang, JK., Peters, O.A., Lee, W. et al. Incidence of three roots and/or four root canals in the permanent mandibular first molars in a Korean sub-population. Clin Oral Invest 17, 105–111 (2013). https://doi.org/10.1007/s00784-012-0687-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00784-012-0687-3