title: The role of orthodontic tooth movement in bone and root mineral density: a study of patients submitted and not submitted to orthodontic treatment.
abstract: BACKGROUND
  Orthodontic force application to the teeth is responsible for a series of biological responses in the bone and dentin, which lead to some alterations of the mineral density of the tissues. Our objective was determine, through cone-beam computed tomography (CBCT), the mineral density of the apical third of the roots of the upper central incisors and of the periapical bone portion surrounding these teeth, in patients submitted to orthodontic treated and untreated individuals.
  
  
  METHODS
  30 untreated individuals and 15 treated ones (treatment cessation at least 1 year before the study) underwent CBCT. Mineral density was assessed in the apical third of the root of the upper central incisors and in the alveolar bone in the periapical region of these teeth. In order to reduce CBCT-related mineral density variability, we standardized the cone-beam tomography device, the image-acquisition settings and the field of view positioning and size. Student's t test was used for the analyses.
  
  
  RESULTS
  bone mineral density (BMD) and root mineral density (RMD), in Hounsfield Units, were 674.84 and 1282.26 for the untreated group and 630.28 and 1370.29 for the treated group, respectively. The differences between the group means were statistically significant for RMD (p<0.05).
  
  
  CONCLUSIONS
  untreated individuals had a significant lower mean RMD in comparison with those submitted to orthodontic treatment.
authors.affiliation: Department of Orthodontics, Juiz de Fora Federal University, Juiz de Fora, Brazil. drmarciocampos@hotmail.com
authors.forename: Marcio José da Silva
authors.initials: MJ
authors.lastname: Campos
authors.forename: Elisa Gomes
authors.initials: EG
authors.lastname: de Albuquerque
authors.forename: Bernardo Caixeiro Hauck
authors.initials: BC
authors.lastname: Pinto
authors.forename: Hélio Moreira
authors.initials: HM
authors.lastname: Húngaro
authors.forename: Marco Abdo
authors.initials: MA
authors.lastname: Gravina
authors.forename: Marcelo Reis
authors.initials: MR
authors.lastname: Fraga
authors.forename: Robert Willer Farinazzo
authors.initials: RW
authors.lastname: Vitral
mesh_terms: D000328:Adult; D015519:Bone Density / Q000502:physiology*; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D007180:Incisor / Q000000981:diagnostic imaging / Q000503:physiopathology; D008297:Male; D009970:Orthodontics / Q000379:methods*; D012016:Reference Values; D014087:Tooth Movement Techniques; D014092:Tooth Root / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055815:Young Adult