Relaction ship btween occlusion function and bone mineral density of the mancibular condyle

为探讨下颌骨髁突骨密度（BMD）的增龄性变化及其与脊柱BMD的相关性，我们对210名健康志愿者（男性114名，女性96名;年龄5 ~ 85岁）的髁突和脊柱（L1-3）进行了定量计算机断层扫描。对73名年轻学生（39名男性和34名女性，年龄在23至25岁之间）进行了一项单独的研究。下颌骨髁状突BMD与脊柱BMD的增龄性变化相似，但以T值表示时，男性和女性下颌骨髁状突BMD的增龄性下降幅度均小于脊柱BMD，女性下颌骨髁状突BMD与脊柱BMD的相关性较高（r = 0.78，p<0.0001），但男性中度（r= 0.58，p< 0.0001）。在青年学生组中，性别相关性差异更为显著;女性下颌骨髁突和脊柱BMD高度相关（r=0.82，p<0.0001），但在男性中未发现相关性（r=0.22）。综上所述，这些结果表明，下颌骨髁突骨密度随着年龄的增长而下降，其下降方式与腰椎骨密度相似，表明其调节机制与脊柱骨密度相同。然而，除了腰椎骨密度之外，其他不确定因素可能参与维持下颌骨骨密度。

We conducted volunteer studies to assess age-related changes of the mandibular condyle bone mineral density (BMD) and its correlation to the spinal BMD.Quantitative computed tomography was performed on the condyles and spines (L1-3) of 210 healthy volunteers (114 men and 96 women ; aged 5 to 85 years). A separate study was performed on 73 young student subjects (39 men and 34 women, aged 23 to 25 years). The mandibular condyle BMDshowed age-related changes similar to those of the spinal BMD.However, when expressed by T-score, the age-related decrement rates of the mandibular condyle BMD in men and women were lesser in extent compared with those of the spine BMD.Correlations in BMD between the mandibular condyle and spine were high in women (r = 0.78, p<0.0001), but moderate in men (r= 0.58, p< 0.0001). Gender-related difference was more dramatic when assessed in the young student group ; the mandibular condyle and spinal BMDs were highly correlated in women (r=0.82, p<0.0001), but no correlation was found in men (r=0.22). Taken together, these results showed that the mandibular condyle BMD decreased with age in a similar fashion to the lumbar spine BMD,suggesting the same regulatory mechanisms as in the spinal BMD.However, aside from the lumbar spine BMD, additonal undefined factor (s) may be involved in maintaining the mandibular BMD.