title: [Analysis of canal morphology of mandibular first premolar].
abstract: OBJECTIVE
  To investigate the canal morphology of bilateral mandibular first premolar using cone-beam CT(CBCT).
  
  
  METHODS
  Ninety-seven CBCT images of bilateral mandibular first premolar were selected . The images were analyzed with NNT software for the number and morphology of canal, groove, position of bifurcation and symmetry of bilateral canal classification.
  
  
  RESULTS
  The canal configuration of mandibular first premolar was type I:83.5%, type III:3.6%, type v:8.8% and C-shaped canal:4.1% by Vertucci's classification.The incidence of groove in complicated canal (75%)was obviously higher than single canal (3.7%). 56.3% of complicated canal bifurcated in middle third, and 31.3% in apical third. 93.8% of mandibular first premolar had bilateral canal symmetry, the symmetry rate of single canal(95.2%) was higher than complicated canal (66.7%).
  
  
  CONCLUSIONS
  CBCT can provide accurate information of canal system, the canal anatomy of mandibular first premolar is complex.
authors: Department of General Dentistry, Shanghai Jiaotong University School of Medicine, Shanghai, China. liaoqian@eastday.com
authors: Qian
authors: Q
authors: Liao
authors: Jun-li
authors: JL
authors: Han
authors: Xiao
authors: X
authors: Xu
mesh_terms: D001641:Bicuspid; D054893:Cone-Beam Computed Tomography; D003786:Dental Pulp Cavity; D006801:Humans; D008334:Mandible; D014092:Tooth Root