[Changes of the microarchitecture of alveolar bone due to different duration of ovariectomy: a Micro-CT study in rats].

PURPOSE: To study the changes of microarchitecture of alveolar bone due to different duration of ovariectomy in rats. METHODS: Twenty-four virgin Sprague-Dawley rats were randomly assigned to ovariectomy group (OVX) or sham-ovariectomy group (sham). OVX rats were subjected to bilateral ovariectomy and sham-ovariectomy was conducted in sham rats. Six rats of each group were sacrificed respectively 3 months and 6 months after surgery. The right semi-maxilla of all rats were scanned by Micro-CT, and the inter-radicular alveolar bone of the maxillary first molar was analyzed. Statistical analysis was carried out with SPSS 16.0 software package. RESULTS: Two-dimensional and three-dimensional reconstructed images of the alveolar bone showed porotic changes in rats both 3 months and 6 months after ovariectomy, including thinner, looser trabeculae and expanded bone marrow. When compared with corresponding sham rats, BMD, BV/TV and Tb.Th of alveolar bone significantly decreased in OVX rats both 3 months and 6 months after ovariectomy (P<0.05). Tb.N and Tb.Sp significantly increased in both OVX groups (P<0.05). When compared with 3 months after ovariectomy, the rats 6 months after ovaroectomy shared deceased BMD, BV/TV and Tb.Th (P<0.05) and increased Tb.N (P<0.05). CONCLUSIONS: Bone loss and deterioration of trabeculae of alveolar bone aggravates with the extended duration of ovariectomy in OVX rats.