Changes in cortical bone mineralization in the mouse mandible with regenerated condyle

Abstract

The objective of this study was to evaluate the effects of condylectomy and of a functional appliance on the mineral content, density, and area of the mandibular cortical bone in a growing mouse model. In the condylectomy group, a unilateral condylectomy was performed on the right side of the mouse mandible. In the condylectomy+appliance group, a functional appliance was used to reposition the mandible after the unilateral condylectomy. All mice were killed 4wk after surgery. Each mandible was then subjected to analyses of cortical bone mineral content (CRT-CNT), cortical bone density (CRT-DEN), and cortical bone area (CRT-A) by peripheral quantitative computed tomography (pQCT). The CRT-CNT, CRT-DEN, and CRT-A values were significantly lower in the condylectomized mandible (right side) than in the non-condylectomized mandible (left side). However, in the condylectomized animals in which a functional appliance was used, the CRT-CNT, CRT-DEN, and CRT-A values became higher than those in the mice treated with condylectomy alone. No significant differences were found in the CRT-CNT, CRT-DEN, and CRT-A between non-condylectomized (left side) mandibles, mandibles treated with condylectomy+functional appliance (right side), and control mandibles. It was thus shown that a functional appliance used to reposition the condylectomized mandible forward in a symmetric position induced improvement of the cortical bone in a mouse model in terms of cortical bone mineral content, density, and area. © 2011 Eur J Oral Sci.