title: Effect of ovariectomy on stimulating intracortical remodeling in rats.
abstract: OBJECTIVE
  Technically primates and dogs represent ideal models to investigate diseases characterized by abnormal intracortical remodeling. High expenses and ethical issues, however, restrict the use of those animals in research. Rodent models have been used as alternatives instead, but their value is limited, if none, because these animals lack intracortical bone remodeling. This study aimed at investigating the effect of ovariectomy onto the stimulation of intracortical remodeling in rat mandibles.
  
  
  METHODS
  Sixteen 12-week-old Spraque-Dawly (SD) female rats were randomly assigned into two groups, receiving either ovariectomy or sham operation. All the rats were sacrificed 18 weeks postoperatively. The entire mandibles were harvested for microcomputed tomography (micro-CT) and histomorphometric assessments.
  
  
  RESULTS
  Micro-CT examination showed significantly decreased bone mineral density (0.95 ± 0.01 versus 1.01 ± 0.02 g/cm(3), P < 0.001) and bone volume (65.78 ± 5.45 versus 87.41 ± 4.12%, P < 0.001) in ovariectomy group. Histomorphometric assessment detected a sixfold increased intracortical bone remodeling as well as an increased bone modeling in mandibles of ovariectomized rats.
  
  
  CONCLUSIONS
  For the first time, to the authors' knowledge, it was detected that ovariectomy stimulates intracortical remodeling in rat mandibles. This animal model might be of use to study various bone diseases associated with an abnormal intracortical remodeling process.
authors.affiliation: Discipline of Oral Diagnosis & Polyclinics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong.
authors.forename: Chun Lei
authors.initials: CL
authors.lastname: Li
authors.affiliation: Discipline of Oral Diagnosis & Polyclinics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong.
authors.forename: Xi Ling
authors.initials: XL
authors.lastname: Liu
authors.affiliation: Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong.
authors.forename: Wei Xin
authors.initials: WX
authors.lastname: Cai
authors.affiliation: Department of Orthopedics & Traumatology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong.
authors.forename: Weijia William
authors.initials: WW
authors.lastname: Lu
authors.affiliation: Discipline of Oral and Maxillofacial Surgery, Faculty of Dentistry, The University of Hong Kong, Hong Kong.
authors.forename: Roger A
authors.initials: RA
authors.lastname: Zwahlen
authors.affiliation: Discipline of Oral Diagnosis & Polyclinics, Faculty of Dentistry, The University of Hong Kong, Prince Philip Dental Hospital, 34 Hospital Road, Hong Kong.
authors.forename: Li Wu
authors.identifier: 0000-0002-7593-0208
authors.initials: LW
authors.lastname: Zheng
mesh_terms: D000818:Animals; D016723:Bone Remodeling / Q000502:physiology*; D005260:Female; D008334:Mandible / Q000166:cytology / Q000000981:diagnostic imaging / Q000502:physiology*; D010052:Ovariectomy; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography