Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan.
Arch Oral Biol. 2013 Aug;58(8):907-11. doi: 10.1016/j.archoralbio.2013.02.003. Epub 2013 Mar 11.
To investigate changes in the bony microstructure of the upper and lower alveolar bone during masticatory loading induced by soft diet feeding in growing rats.
Three-week-old male Wistar rats were randomly divided into two groups. Rats were fed with either pellets [control group (n=6)] or a soft diet [experimental group (n=6)] for nine weeks. 3D-microstructure of the alveolar bone of the first molar region (M1) was examined by micro-CT analysis.
Micro-CT images showed increased marrow spaces of the inter-radicular alveolar bone around the rat mandibular M1 in the experimental group compared with that in the control group. The bone volume/tissue volume ratio, trabecular thickness, trabecular number, mean intercept length, trabecular width and trabecular star volume for the mandibular M1 inter-radicular alveolar bone were lower in the experimental group than in the control group. Marrow space star volume was increased in the experimental group compared with the control group.
These results suggest that alveolar osteopenia is more extensive in the mandible than the maxilla in rats that experience low masticatory loading during growth.
研究在软食喂养诱导的咀嚼负荷下,生长期大鼠上下牙槽骨骨微观结构的变化。
3 周龄雄性 Wistar 大鼠随机分为两组。大鼠分别喂食颗粒饲料(对照组,n=6)或软食(实验组,n=6)9 周。通过 micro-CT 分析检测第一磨牙区域(M1)牙槽骨的 3D 微观结构。
微 CT 图像显示实验组大鼠下颌 M1 根尖间牙槽骨的骨髓腔较对照组增大。实验组下颌 M1 根尖间牙槽骨的骨体积/组织体积比、骨小梁厚度、骨小梁数量、平均截距长度、骨小梁宽度和骨小梁星形体积均低于对照组。实验组骨髓腔星形体积大于对照组。
这些结果表明,在生长过程中咀嚼负荷较低的大鼠,下颌牙槽骨骨质疏松比上颌更广泛。