title: Crown and root lengths of incisors, canines, and premolars measured by cone-beam computed tomography in patients with malocclusions.
abstract: OBJECTIVE
  The purposes of this study were to determine the accuracy of crown and root length measurements of premolars using cone-beam computed tomography (CBCT) and to generate reference CBCT-based data on incisor, canine, and premolar lengths in patients with malocclusions.
  
  
  METHODS
  Imaging was performed using a CBCT scanner with a 0.292-mm voxel size and 12-bit grayscale. The CBCT-based length measurements were compared with direct measurements of 94 subsequently extracted premolars without metal restorations using the paired t-test. Furthermore, the crown and root lengths of incisors, canines, and premolars in 62 Korean patients with malocclusions were measured using CBCT, and Pearson's correlation coefficients were calculated to examine the relationship between the crown and root length measurements of each tooth type.
  
  
  RESULTS
  The differences between the CBCT-based and direct measurements of the extracted premolars were not significant, with 95% limits of agreement of -0.90 to 0.90 mm for crown length and -1.23 to 1.18 mm for root length. Weak positive correlations between the crown and root length measurements were observed for the mandibular canine and premolars.
  
  
  CONCLUSIONS
  The CBCT-based measurements showed a wider range of limits of agreements for root length than for crown length. The CBCT-based data can be used as a reference for evaluating root length and resorption of teeth without metal restorations in patients with malocclusions.
authors.affiliation: Department of Orthodontics, School of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Seon-Young
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Orthodontics, School of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Sung-Hoon
authors.initials: SH
authors.lastname: Lim
authors.affiliation: Department of Orthodontics, School of Dentistry, Chosun University, Gwangju, Korea.
authors.forename: Sung-Nam
authors.initials: SN
authors.lastname: Gang
authors.affiliation: Division in Anatomy and Developmental Biology, College of Dentistry, Yonsei University, Seoul, Korea.
authors.forename: Hee-Jin
authors.initials: HJ
authors.lastname: Kim
keywords: Anatomy; Computed tomography; Root resorption