title: Bone remodeling during orthodontic tooth movement in rats with type 2 diabetes.
abstract: BACKGROUND
  Type 2 diabetes is known to affect bone metabolism. In this study, we aimed to determine the effects of type 2 diabetes on bone remodeling during orthodontic tooth movement.
  
  
  METHODS
  The 48 rats were divided into 4 groups: Wistar control group (n = 8), Goto-Kakizaki (GK) control group (n = 8), Wistar appliance group (n = 16), and GK appliance group (n = 16). The distances between the teeth were measured weekly. On day 42, maxillary alveolar bone specimens were obtained for histologic evaluation and determination of the gene expression levels of the receptor activator of nuclear factor ҡB (RANK), RANK ligand (RANKL), and osteoprotegerin (OPG).
  
  
  RESULTS
  No significant difference was observed in the levels of tooth movement between the 2 appliance groups. After orthodontic force application, the alveolar bone volume and osteoblast surface in the GK rats were diminished compared with those in the Wistar rats. The increase in the osteoclast surface relative to the control groups was 2.4-fold greater in the GK rats than in the Wistar rats. Significant upregulations of the RANK and OPG gene expression levels in the Wistar appliance group were observed. The RANKL/OPG ratio was increased in the GK appliance group compared with the Wistar appliance group.
  
  
  CONCLUSIONS
  Diminished bone formation and slightly increased bone resorption were observed during orthodontic tooth movement in the rats with type 2 diabetes.
authors.affiliation: Postgraduate student, Department of Orthodontics, University Medical Centre, Ljubljana, Slovenia. Electronic address: alja.meh@kclj.si.
authors.forename: Alja
authors.initials: A
authors.lastname: Plut
authors.affiliation: Researcher, Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Špela
authors.initials: Š
authors.lastname: Sprogar
authors.affiliation: Research assistant professor, Institute of Pharmacology and Experimental Toxicology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia; associate professor, Department of Applied Natural Sciences, Faculty of Mathematics, Natural Sciences and Information Technologies, University of Primorska, Koper, Slovenia.
authors.forename: Gorazd
authors.initials: G
authors.lastname: Drevenšek
authors.affiliation: Assistant, Institute of Cell Biology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Samo
authors.initials: S
authors.lastname: Hudoklin
authors.affiliation: Assistant, Division of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Janja
authors.initials: J
authors.lastname: Zupan
authors.affiliation: Professor, Division of Clinical Biochemistry, Faculty of Pharmacy, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Janja
authors.initials: J
authors.lastname: Marc
authors.affiliation: Professor, Department of Orthodontics, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.
authors.forename: Martina
authors.initials: M
authors.lastname: Drevenšek
mesh_terms: D000539:Alveolar Process / Q000473:pathology; D000818:Animals; D016723:Bone Remodeling / Q000502:physiology*; D001862:Bone Resorption / Q000503:physiopathology; D003924:Diabetes Mellitus, Type 2 / Q000150:complications* / Q000503:physiopathology; D004195:Disease Models, Animal; D007180:Incisor / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D008963:Molar / Q000473:pathology; D009929:Organ Size; D009969:Orthodontic Wires; D010006:Osteoblasts / Q000473:pathology; D010010:Osteoclasts / Q000473:pathology; D010012:Osteogenesis / Q000502:physiology; D053244:Osteoprotegerin / Q000032:analysis; D053245:RANK Ligand / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D017208:Rats, Wistar; D053246:Receptor Activator of Nuclear Factor-kappa B / Q000032:analysis; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D015854:Up-Regulation
chemical_list: D053244:Osteoprotegerin; D053245:RANK Ligand; D053246:Receptor Activator of Nuclear Factor-kappa B; C506032:Tnfrsf11b protein, rat