title: Ovariectomy induces osteoporosis in the maxillary alveolar bone: an in vivo micro-CT and histomorphometric analysis in rats.
abstract: OBJECTIVE
  To investigate whether porotic changes occur in maxillary alveolar bone in ovariectomized rats.
  
  
  METHODS
  Thirty-two 6-week-old female Sprague-Dawley rats were divided into an ovariectomy group (OVX) and a sham-ovariectomy group (sham). Twelve weeks after surgery, maxillae of 16 rats (eight OVX and eight sham) were analyzed by micro-CT. Inter-radicular alveolar bone of the maxillary first molar was reconstructed and analyzed. The remaining 16 maxillae were used for histochemistry, including hematoxylin-eosin staining and tartrate-resistant acid phosphatase enzyme staining.
  
  
  RESULTS
  Three-dimensional reconstructed images of the irregular alveolar bone showed an intuitive view of porotic changes in the OVX group. The alveolar bone in OVX rats had a porous microarchitecture including lower bone mass and a looser structure of more widely separated trabeculae. Bone mineral density (BMD), bone volume fraction (BV/TV), and trabecular thickness (Tb.Th.) were significantly lower in the OVX group than those in the sham group (P < 0.05). Trabecular separation (Tb.Sp.) increased significantly in the OVX rats compared to the sham rats (P < 0.05). Histomorphometric analysis of alveolar bone also revealed porotic changes in the OVX rats. Bone area ratio significantly decreased in the OVX group compared with the sham group (P < 0.01). There were also more osteoclasts present in the alveolar bone of OVX rats compared to sham rats (P < 0.05).
  
  
  CONCLUSIONS
  Ovariectomy induces osteoporosis in maxillary alveolar bone in rats, which may be related to the increased number of osteoclasts.
authors.affiliation: Department of Oral and Cranio-maxillofacial Science, Shanghai 9th People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China; Shanghai Key Laboratory of Stomatology, Shanghai, China.
authors.forename: Q-G
authors.initials: QG
authors.lastname: Dai
authors.forename: P
authors.initials: P
authors.lastname: Zhang
authors.forename: Y-Q
authors.initials: YQ
authors.lastname: Wu
authors.forename: X-H
authors.initials: XH
authors.lastname: Ma
authors.forename: J
authors.initials: J
authors.lastname: Pang
authors.forename: L-Y
authors.initials: LY
authors.lastname: Jiang
authors.forename: B
authors.initials: B
authors.lastname: Fang
mesh_terms: D000539:Alveolar Process / Q000473:pathology*; D000818:Animals; D005260:Female; D008437:Maxilla; D010010:Osteoclasts / Q000166:cytology; D010024:Osteoporosis / Q000209:etiology*; D010052:Ovariectomy; D051381:Rats; D017207:Rats, Sprague-Dawley; D055114:X-Ray Microtomography
keywords: alveolar bone; micro-CT; osteoporosis; ovariectomy