Mandibular condyle bone mineral density measurement by quantitative computed tomography

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，对210例（男114例，女96例，年龄5-85岁）健康志愿者的髁突和脊柱（L1-3）进行了定量CT检查。对73名年轻学生（39名男性和34名女性，年龄23-25岁）进行了单独的研究。下颌骨髁突骨密度的下降率男性与脊柱骨密度的下降率相似，女性与脊柱骨密度的下降率相似，但女性下颌骨髁突骨密度的下降率低于LI-3骨密度，下颌骨髁突骨密度与脊柱骨密度的相关系数男女相似。在年轻学生组中进行评估时，发现性别相关差异显著;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，在下颌骨髁突和脊柱BMD中存在相同的调节机制。然而，除了脊柱骨密度，其他不确定的因素，包括来自咬合的机械应力，可能参与维持下颌骨骨密度。

We conducted volunteer studies to asses age-related changes of 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 subjects (114 men and 96 women, aged 5-85 years). A separate study was performed on 73 young student subjects (39 men and 34 women, aged 23-25 years). The mandibular condyle BMD showed a decrement rate similar to spinal BMD in men, but in women the decrement rate similar to spinal BMD in men, but in women the decrement rate of the mandibular condyle BMD was lower than that of the LI-3 BMD.On the other hand, correlation coefficients in BMD between the mandibular condyle and spine were similar in women and men. Gender-refated differences were found to be 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 suggest that the same regulatory mechanisms exist in the mandibular condyle and spine BMDs. However, aside from the spine BMD, additional undefined factor(s), including mechanical stress from the occlusion, may be involved in maintaining mandibular BMD.