title: Locally limited inhibition of bone resorption and orthodontic relapse by recombinant osteoprotegerin protein.
abstract: OBJECTIVE
  To determine minimal dose levels required for local inhibition of orthodontic relapse by recombinant OPG protein (OPG-Fc), while also determining effects of injected OPG-Fc on alveolar bone and long bone.
  
  
  METHODS
  The Department of Orthodontics and Pediatric Dentistry at the University of Michigan. Eighteen male Sprague Dawley rats.
  
  
  METHODS
  Maxillary molars were moved with nickel-titanium springs and then allowed to relapse in Sprague Dawley rats. Upon appliance removal, animals were injected with a single dose of 1.0 mg/kg OPG-Fc, 0.1 mg/kg OPG-Fc, or phosphate-buffered saline (vehicle) just distal to the molar teeth. Tooth movement measurements were made from stone casts, which were scanned and digitally measured. Alveolar tissues were examined by histology. Micro-computed tomography was used to quantify changes in alveolar and femur bone.
  
  
  RESULTS
  Local injection of OPG-Fc inhibited molar but not incisor relapse, when compared to vehicle-injected animals. No significant differences in alveolar or femur bone were seen between the three treatment groups after 24 days of relapse.
  
  
  CONCLUSIONS
  Our results demonstrate that a single local injection of OPG-Fc effectively inhibits orthodontic relapse, with minimal systemic bone metabolic effects. Our results also show that a single injection of OPG-Fc will influence tooth movement only in teeth close to the injection site. These findings indicate that OPG-Fc has potential as a safe and effective pharmacological means to locally control osteoclasts, for uses such as maintaining anchorage during orthodontic tooth movement and preventing orthodontic relapse in humans.
authors: Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, MI, USA.
authors: D A
authors: DA
authors: Schneider
authors: S M
authors: SM
authors: Smith
authors: C
authors: C
authors: Campbell
authors: T
authors: T
authors: Hayami
authors: S
authors: S
authors: Kapila
authors: N E
authors: NE
authors: Hatch
mesh_terms: D000539:Alveolar Process / Q000187:drug effects* / Q000473:pathology; D000818:Animals; D015519:Bone Density / Q000187:drug effects; D016723:Bone Remodeling / Q000187:drug effects; D001862:Bone Resorption / Q000473:pathology / Q000517:prevention & control*; D005269:Femur / Q000187:drug effects / Q000473:pathology; D007180:Incisor / Q000187:drug effects; D007267:Injections; D008297:Male; D008437:Maxilla / Q000187:drug effects / Q000473:pathology; D003765:Models, Dental; D008963:Molar / Q000187:drug effects; D009969:Orthodontic Wires; D010010:Osteoclasts / Q000187:drug effects / Q000473:pathology; D053244:Osteoprotegerin / Q000008:administration & dosage / Q000627:therapeutic use*; D014677:Pharmaceutical Vehicles; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D011994:Recombinant Proteins; D012008:Recurrence; D014087:Tooth Movement Techniques / Q000295:instrumentation / Q000379:methods*; D055114:X-Ray Microtomography / Q000379:methods
chemical_list: D053244:Osteoprotegerin; D014677:Pharmaceutical Vehicles; D011994:Recombinant Proteins; C506032:Tnfrsf11b protein, rat
keywords: X-ray microtomography; alveolar resorption; bone density conservation agents; orthodontics; osteoclasts