title: Gender difference and root canal morphology in mandibular premolars: A cone-beam computed tomography study in an Iranian population.
abstract: BACKGROUND
  Mandibular premolars are of the most difficult teeth to treat endodontically.
  
  
  OBJECTIVE
  To compare the root canal morphology of mandibular premolars between two genders in an Iranian population.
  
  
  METHODS
  Totally, 230 cone-beam computed tomography images of the mandibles belonged to 115 males and 115 females were evaluated in the three spatial planes.
  
  
  METHODS
  The total number of roots and canals in the mandibular premolars was counted, and the difference between males and females were analyzed.
  
  
  METHODS
  Data were analyzed using Chi-square test. The significance level was set as P < 0.05.
  
  
  RESULTS
  The majority of mandibular first and second premolars had one root (85.7% and 94.8%, respectively) and one canal (63.9% and 78.3%, respectively). The number of roots in the mandibular first premolars had statistically significant difference between two genders (P = 0.001). There was no significant difference between two genders in the number of roots (P = 0.208) and canals (P = 0.498) in the mandibular second premolars.
  
  
  CONCLUSIONS
  According to the results of this study, the root canal morphology in the mandibular first premolars had statistically significant difference between two genders.
authors: Department of Endodontic, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Maryam
authors: M
authors: Kazemipoor
authors: Department of Endodontic, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Afrooz
authors: A
authors: Hajighasemi
authors: Department of Endodontic, School of Dentistry, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
authors: Roqayeh
authors: R
authors: Hakimian
keywords: Cone-beam computed tomography; mandibular premolar; number of canals; number of roots; root canal morphology