title: Cervical vertebral bone mineral density changes in adolescents during orthodontic treatment.
abstract: BACKGROUND
  The cervical vertebral maturation (CVM) stages have been used to estimate facial growth status. In this study, we examined whether cone-beam computed tomography images can be used to detect changes of CVM-related parameters and bone mineral density distribution in adolescents during orthodontic treatment.
  
  
  METHODS
  Eighty-two cone-beam computed tomography images were obtained from 41 patients before (14.47 ± 1.42 years) and after (16.15 ± 1.38 years) orthodontic treatment. Two cervical vertebral bodies (C2 and C3) were digitally isolated from each image, and their volumes, means, and standard deviations of gray-level histograms were measured. The CVM stages and mandibular lengths were also estimated after converting the cone-beam computed tomography images.
  
  
  RESULTS
  Significant changes for the examined variables were detected during the observation period (P ≤0.018) except for C3 vertebral body volume (P = 0.210). The changes of CVM stage had significant positive correlations with those of vertebral body volume (P ≤0.021). The change of the standard deviation of bone mineral density (variability) showed significant correlations with those of vertebral body volume and mandibular length for C2 (P ≤0.029).
  
  
  CONCLUSIONS
  The means and variability of the gray levels account for bone mineral density and active remodeling, respectively. Our results indicate that bone mineral density distribution and the volume of the cervical vertebral body changed because of active bone remodeling during maturation.
authors.affiliation: Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus.
authors.forename: Bethany
authors.initials: B
authors.lastname: Crawford
authors.affiliation: Associate professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus. Electronic address: kim.2508@osu.edu.
authors.forename: Do-Gyoon
authors.initials: DG
authors.lastname: Kim
authors.affiliation: Predoctoral student, College of Dentistry, Ohio State University, Columbus.
authors.forename: Eun-Sang
authors.initials: ES
authors.lastname: Moon
authors.affiliation: Resident, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Johnson
authors.affiliation: Professor, Division of Orthodontics, College of Dentistry, Ohio State University, Columbus.
authors.forename: Henry W
authors.initials: HW
authors.lastname: Fields
authors.affiliation: Associate professor, Department of Orthodontics, School of Dental Medicine, Case Western Reserve University, Cleveland, Ohio.
authors.forename: J Martin
authors.initials: JM
authors.lastname: Palomo
authors.affiliation: Professor, Division of Restorative, Prosthetic and Primary Care Dentistry, College of Dentistry, Ohio State University, Columbus.
authors.forename: William M
authors.initials: WM
authors.lastname: Johnston
mesh_terms: D000293:Adolescent; D001368:Axis, Cervical Vertebra / Q000000981:diagnostic imaging / Q000254:growth & development / Q000502:physiology; D015519:Bone Density / Q000502:physiology*; D016723:Bone Remodeling / Q000502:physiology; D002508:Cephalometry / Q000379:methods; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging / Q000254:growth & development*; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000254:growth & development; D009971:Orthodontics, Corrective; D012189:Retrospective Studies