Tokimasa C, Kawata T, Fujita T, Kaku M, Kawasoko S, Kohno S, Tanne K
Department of Orthodontics, Hiroshima University Faculty of Dentistry, Minamiku, Hiroshima 734-8553, Japan.
Arch Oral Biol. 2000 Oct;45(10):871-8. doi: 10.1016/s0003-9969(00)00057-1.
It is well accepted that reduced masticatory function induced by a diet with soft physical consistency causes alterations in the craniofacial morphology in growing animals. It is assumed that these alterations are associated with reduced proliferative activity of osteoblasts on the bone surface, indicating a significant role for mechanical stimuli mediated by various local growth factors including insulin-like growth factor-I (IGF-I). Here, the effects of IGF-I on the linear growth of nasal and premaxillary bones subjected to different masticatory loadings were examined. The length of the nasal bone and the width of the premaxilla were measured. These dimensions were significantly greater in mice fed a solid diet than in mice fed a granulated diet. In animals treated with IGF-I, the nasal bone length and premaxillary width increased significantly in a subgroup receiving a solid diet, but these changes were not found in a similar group fed a granulated diet. No statistically significant differences in these dimensions were found between solid-diet mice injected with saline and granulated-diet group injected with IGF-I. It is concluded that IGF-I induces nasal and premaxillary growth, and that its effect is enhanced or accelerated by increased mechanical masticatory loading.
人们普遍认为，质地柔软的饮食导致咀嚼功能下降会使生长中的动物颅面形态发生改变。据推测，这些改变与骨表面成骨细胞增殖活性降低有关，这表明包括胰岛素样生长因子-I（IGF-I）在内的各种局部生长因子介导的机械刺激具有重要作用。在此，研究了IGF-I对承受不同咀嚼负荷的鼻骨和前上颌骨线性生长的影响。测量了鼻骨的长度和前上颌骨的宽度。喂食固体食物的小鼠的这些尺寸明显大于喂食颗粒食物的小鼠。在用IGF-I治疗的动物中，接受固体食物的亚组中鼻骨长度和前上颌骨宽度显著增加，但在喂食颗粒食物的类似组中未发现这些变化。注射生理盐水的固体食物小鼠和注射IGF-I的颗粒食物组之间在这些尺寸上没有统计学上的显著差异。得出的结论是，IGF-I可诱导鼻骨和前上颌骨生长，并且咀嚼机械负荷增加会增强或加速其作用。
