title: Early effects of orthodontic forces on osteoblast differentiation in a novel mouse organ culture model.
abstract: OBJECTIVE
  To develop a mouse orthodontic organ culture model and examine early-induced changes in osteoblast differentiation markers within the periodontal ligament (PDL) and alveolar bone.
  
  
  METHODS
  Mandibles from 4- to 12-week-old transgenic mice were dissected and hemisected. A conventional superelastic orthodontic spring (25 grams) was bonded to the incisor and first molar on one side of the mandible; the other side served as a control. Dissected mandibles were cultured for 6 hours and then were histologically analyzed for proliferation (BrdU immunostaining) and fluorescent protein expression. Additionally, an in vivo model using the same methods was applied to 3.6 Col1-GFP transgenic mice.
  
  
  RESULTS
  In vitro, after 6 hours of orthodontic loading, a significant increase was noted in 3.6Col1-GFP- and BSP-GFP-positive cells within the tension side of the PDL compared with unloaded controls. On the compression side, a significant decrease in positive cells in 3.6Col1-GFP mice was observed in the PDL compared with unloaded controls. In vivo, the same tendencies were found.
  
  
  CONCLUSIONS
  This novel in vitro mandibular tooth movement organ culture model coupled with transgenic mouse technology provides a powerful tool for delineating initial cellular and molecular events of orthodontic tooth movement.
authors.affiliation: Department of Craniofacial Sciences, University of Connecticut School of Dental Medicine, Farmington, 06032, USA. furibe@uchc.edu
authors.forename: Flavio
authors.initials: F
authors.lastname: Uribe
authors.forename: Zhana
authors.initials: Z
authors.lastname: Kalajzic
authors.forename: John
authors.initials: J
authors.lastname: Bibko
authors.forename: Ravindra
authors.initials: R
authors.lastname: Nanda
authors.forename: Christopher
authors.initials: C
authors.lastname: Olson
authors.forename: David
authors.initials: D
authors.lastname: Rowe
authors.forename: Sunil
authors.initials: S
authors.lastname: Wadhwa
mesh_terms: D000539:Alveolar Process / Q000166:cytology* / Q000378:metabolism; D000818:Animals; D001973:Bromodeoxyuridine; D002454:Cell Differentiation; D024042:Collagen Type I / Q000096:biosynthesis; D049452:Green Fluorescent Proteins / Q000096:biosynthesis; D058574:Integrin-Binding Sialoprotein / Q000096:biosynthesis; D051379:Mice; D008822:Mice, Transgenic; D009924:Organ Culture Techniques; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D014087:Tooth Movement Techniques / Q000295:instrumentation
chemical_list: D024042:Collagen Type I; D058574:Integrin-Binding Sialoprotein; D049452:Green Fluorescent Proteins; D001973:Bromodeoxyuridine