title: Use of cone-beam computed tomography to evaluate C-shaped root canal systems in mandibular second molars in a Turkish subpopulation: a retrospective study.
abstract: OBJECTIVE
  To use cone-beam computed tomography (CBCT) to evaluate the prevalence and anatomical features of C-shaped canals in permanent mandibular second molars amongst members of a Turkish population.
  
  
  METHODS
  An endodontist and oral radiologist examined CBCT images of 271 Turkish mandibular second molars to determine the presence of C-shaped canals and their anatomical features. Root canal configurations at five different levels were categorized using the classification of Fan et al. (Journal of Endodontics, 30, 2004a,b, 899-903; 904-8). Bilateral or unilateral occurrence of C-shaped canals and their relationships with gender, age and tooth position were examined and statistically analysed using the chi-squared test.
  
  
  RESULTS
  Of the 271 mandibular second molars examined, 24 (8.9%) molars from 17 patients had a C-shaped root canal system. The prevalence of bilateral C-shaped canals was 6.3% amongst 111 patients with bilateral mandibular second molars. There were no significant differences in the distribution of C-shaped canals with respect to gender or age. Only one tooth had the same canal configuration from the orifice to the apex. In the remainder of the teeth, the cross-sectional canal configuration changed at different levels of the root.
  
  
  CONCLUSIONS
  The configuration of C-shaped canals varied along the length of the root. The prevalence of C-shaped canals in mandibular second molars in this Turkish population was lower than in other Asian populations.
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Kocaeli University, Kocaeli.
authors.forename: D
authors.initials: D
authors.lastname: Helvacioglu-Yigit
authors.forename: A
authors.initials: A
authors.lastname: Sinanoglu
mesh_terms: D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003786:Dental Pulp Cavity / Q000000981:diagnostic imaging*; D006801:Humans; D012189:Retrospective Studies; D014421:Turkey
keywords: C-shaped canal; canal configuration; cone-beam computed tomography; mandibular second molars