Department of Oral Surgery, Medical University of Vienna, Austria.
Clin Oral Implants Res. 2011 May;22(5):500-5. doi: 10.1111/j.1600-0501.2010.02031.x. Epub 2010 Nov 19.
Cortical porosity and thickness of the axial and the appendicular skeleton are predictors of osteoporotic fractures. In the jawbone, however, cortical porosity and thickness may affect the mechanical stability of dental implants. We have shown previously that the jawbone of osteoporotic sheep has impaired trabecular structures, but whether catabolic bone turnover also accounts for the cortical bone porosity remains unknown.
We compared mandibular bone from six geriatric sheep subjected to ovariectomy, calcium/vitamin D restriction, and methylprednisolone administration to those of six healthy adult control sheep. Histological ground sections were prepared from the diastema, first and second premolars, and postmolar region. Cortical porosity and thickness were assessed by histomorphometry.
Cortical porosity was higher in osteoporotic sheep than in adult controls in the diastema and in the first and second premolar region. In the postmolar region, the difference failed to reach the level of significance. The changes were even more prominent when histomorphometry was restricted to the inner millimeter of the mandibular cortex. In contrast, induction of osteoporosis did not have a discernable effect on cortical thickness.
These results demonstrate that cortical porosity of mandibles is more pronounced in geriatric osteoporotic sheep than in adult controls.
皮质骨孔隙率和厚度是预测骨质疏松性骨折的因素。然而，在颌骨中，皮质骨孔隙率和厚度可能会影响牙种植体的机械稳定性。我们之前已经表明，骨质疏松绵羊的颌骨具有受损的小梁结构，但分解代谢性骨转换是否也导致皮质骨孔隙率增加尚不清楚。
我们比较了 6 只接受卵巢切除术、钙/维生素 D 限制和甲基强的松龙治疗的老年绵羊以及 6 只健康成年对照组绵羊的下颌骨。从齿隙、第一和第二前磨牙以及磨牙区制备组织学地面切片。通过组织形态计量学评估皮质骨孔隙率和厚度。
骨质疏松绵羊的皮质骨孔隙率高于成年对照组，在齿隙和第一和第二前磨牙区更为明显。在磨牙区，差异未达到显著水平。当组织形态计量学仅限于下颌骨皮质的内 1 毫米时，变化更为明显。相比之下，诱导骨质疏松症对皮质厚度没有明显影响。
这些结果表明，老年骨质疏松绵羊的下颌骨皮质骨孔隙率比成年对照组更为明显。
