Methods: Young (4-weeks old) and adult (13-weeks old) CCI and control rats were subjected to morphometric and mechanical analyses. A total of 24 male rats were examined (six per group). Following anesthesia, all animals were sacrificed and mandibles were removed. All experiments were performed according to the guidelines of the Institutional Animal Care and Use Committee of St. Marianna University School of Medicine. The specimens were scanned and analyzed using an X-ray micro-CT system, a peripheral quantitative computed tomography, and a soft X-ray system. Three-dimensional reconstruction and structural analysis was then performed. In addition, a three-point bending test of mandibles was performed in each group.
Results: Both young and adult CCI rats showed systematic changes, exhibited as an overall reduction in size. Bone volume of CCI rats and control rats was not significantly different in 4-week-old rats, but was significantly different between CCI and control rats at 13-weeks of age. Additionally, strength, as measured in the three-point bending test, was not significantly different between 4-week-old CCI rats and control rats. However, at 13-weeks CCI and control rats showed significant strength differences.
Conclusion: The results confirmed the usefulness of CCI rats as an animal disease model.