title: Cone-beam computed tomography analysis of root and canal morphology of mandibular premolars in a Spanish population.
abstract: OBJECTIVE
  This study aimed to investigate the clinical anatomy of lower premolar roots in a Spanish population by using cone-beam computed tomography (CBCT), correlating findings with patient gender and tooth type.
  
  
  METHODS
  Using 70 CBCT images, we evaluated 126 healthy, untreated, well-developed lower premolars. The number and morphology of roots and root canals, and the foramina number were assessed. Results for gender and tooth type were compared using the chi-squared and ANOVA tests.
  
  
  RESULTS
  The average length of teeth and roots was significantly higher in men (p=0.00). All 126 premolars had a single root. One canal was found in 83.3% of the premolars, with no gender or tooth type differences; Vertucci configuration types I and V were the most prevalent. The first premolars showed significantly greater variability than the second premolars (p=0.03). A single apical foramen was found in 89.7% of the premolars, with no differences by tooth type. Women had a significantly higher prevalence of two apical foramina than men (p=0.04). Some degree of curvature was observed in 65% of the premolars, with no differences by gender or tooth type. A root angle of more than 20° was found in 12.98% of the premolars, without any differences by gender or tooth.
  
  
  CONCLUSIONS
  All premolars were single-rooted. One canal had the most prevalent morphology. More variability in canal anatomy was found in the first premolars. Curvatures greater than 20° were found at less than 5 mm from the apex.
authors.affiliation: Department of Stomatology, Universitat de Valencia, Valencia, Spain.
authors.forename: Carmen
authors.initials: C
authors.lastname: Llena
authors.affiliation: Fernández Ugedo y Chaves Clinic, Alicante, Spain.
authors.forename: Jaime
authors.initials: J
authors.lastname: Fernandez
authors.affiliation: Department of Stomatology, Universitat de Valencia, Valencia, Spain.
authors.forename: Pablo Sebastián
authors.initials: PS
authors.lastname: Ortolani
authors.affiliation: Department of Stomatology, Universitat de Valencia, Valencia, Spain.
authors.forename: Leopoldo
authors.initials: L
authors.lastname: Forner
keywords: Anatomy, Regional; Bicuspid; Cone-Beam Computed Tomography; Mandible