title: Evaluation of root canal configuration of mandibular molars in a Brazilian population by using cone-beam computed tomography: an in vivo study.
abstract: BACKGROUND
  The aim of this study was to analyze and characterize root canal morphology of mandibular molars of the Brazilian population by using cone-beam computed tomography (CBCT).
  
  
  METHODS
  Patients who required CBCT radiographic examinations as part of their routine examination, diagnosis, and treatment planning were enrolled in the study. A total of 460 healthy, untreated, fully developed mandibular first and second molars were included (234 first molars and 226 second molars). The following observations were recorded: (1) number of roots and their morphology, (2) number of canals per root, (3) C-shaped canals, and (4) primary variations in the morphology of the root canal systems.
  
  
  RESULTS
  First molars showed a higher prevalence of 2 canals in the mesial root and 1 in the distal root with 2 separate roots (74%). In the mandibular second molars, the presence of 2 separate roots with 2 canals in the mesial root and 1 canal in the distal root represented 54% of the total. In 32% of the cases, 2 separate roots with 1 canal each in the mesial and distal roots were presented. The incidence of C-shaped canals was 1.7% of first molars and 3.5% of second molars.
  
  
  CONCLUSIONS
  A higher prevalence of 2 separate roots with 2 canals in the mesial root and 1 canal in the distal root was observed in mandibular first and second molars (74% and 54%, respectively). Also, a lower incidence of C-shaped canals and 3-rooted teeth was observed in a Brazilian population. CBCT is a clinically useful tool for endodontic diagnosis and treatment.
authors.affiliation: Department of Endodontology, Grande Rio University, Rio de Janeiro, Brazil. nogueiraemmanuel@hotmail.com
authors.forename: Emmanuel João Nogueira Leal
authors.initials: EJ
authors.lastname: Silva
authors.forename: Yuri
authors.initials: Y
authors.lastname: Nejaim
authors.forename: Amaro V
authors.initials: AV
authors.lastname: Silva
authors.forename: Francisco
authors.initials: F
authors.lastname: Haiter-Neto
authors.forename: Nestor
authors.initials: N
authors.lastname: Cohenca
mesh_terms: D063405:Anatomic Variation; D001938:Brazil / Q000208:ethnology; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003786:Dental Pulp Cavity / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005006:Ethnicity; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging; D008963:Molar / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014092:Tooth Root / Q000033:anatomy & histology / Q000000981:diagnostic imaging