Division of Bone Diseases [WHO Collaborating Center for Osteoporosis Prevention], Department of Internal Medicine Specialties, University Hospitals of Geneva and Faculty of Radiology, Geneva, Switzerland; Department of Orthodontics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
Department of Orthodontics, Faculty of Medicine, University of Geneva, Geneva, Switzerland.
J Biomech. 2014 Aug 22;47(11):2666-71. doi: 10.1016/j.jbiomech.2014.05.012. Epub 2014 May 23.
BACKGROUND/AIM: In a previous study we showed that mandibular alveolar (trabecular) bone appears to be less sensitive to estrogen deficiency than the proximal tibia spongiosa. We hypothesized that the mechanical loading of the alveolar process during mastication may protect the alveolar bone from the detrimental effects observed in other skeletal sites. To test this hypothesis we compared the effect of ovariectomy on the mandibular alveolar bone and the proximal tibia spongiosa of rats fed either a normal (hard) or a soft diet.
Forty six-month-old female Sprague-Dawley rats underwent trans-abdominal ovariectomy (OVX) or sham operation (SHAM). Half of the animals received their food in the usual form of pellets (hard consistency), while the other half received a soft, porridge-like, isocaloric diet of identical composition (soft consistency). Micro-computed tomographic histomorphometry was used to evaluate the trabecular micro-architecture. A two-factor analysis of variance was used to test for effects and interaction of ovariectomy and/or soft diet.
OVX had a significantly negative effect on the proximal tibia spongiosa (all parameters under study except trabecular thickness; p<0.001) and on the mandibular alveolar bone (trabecular number and spacing; p<0.05). Soft diet led to a further decrease of mandibular BV/TV (p<0.01), trabecular thickness (p<0.05) and number (p<0.05), as well as increase of separation (p<0.001). A significant interaction was observed between OVX and soft diet concerning the mandibular BV/TV, as well as trabecular thickness and spacing (p<0.05).
Normal (hard) diet limited significantly the negative effects of estrogen deficiency on mandibular alveolar bone micro-architecture four months after ovariectomy.
背景/目的：在之前的研究中，我们发现下颌牙槽（小梁）骨似乎比胫骨近端松质骨对雌激素缺乏的敏感性更低。我们假设咀嚼过程中对牙槽骨的机械加载可能会保护牙槽骨免受其他骨骼部位观察到的不利影响。为了验证这一假设，我们比较了去卵巢对正常（硬）或软饮食喂养的大鼠下颌牙槽骨和胫骨近端松质骨的影响。
46 月龄雌性 Sprague-Dawley 大鼠行腹侧卵巢切除术（OVX）或假手术（SHAM）。一半的动物以通常的颗粒形式（硬质地）接受食物，而另一半则以软质、粥状、等热量的相同成分的饮食（软质地）接受食物。微计算机断层扫描组织形态计量学用于评估小梁微结构。采用两因素方差分析检验卵巢切除术和/或软饮食的作用和相互作用。
OVX 对胫骨近端松质骨（所有研究参数，除了小梁厚度外；p<0.001）和下颌牙槽骨（小梁数量和间隔；p<0.05）均有显著的负影响。软饮食导致下颌 BV/TV（p<0.01）、小梁厚度（p<0.05）和数量（p<0.05）进一步下降，以及间隔增加（p<0.001）。OVX 和软饮食对下颌 BV/TV 以及小梁厚度和间隔均存在显著的交互作用（p<0.05）。
正常（硬）饮食显著限制了雌激素缺乏对去卵巢后四个月下颌牙槽骨微观结构的负面影响。
