骨密度对正畸支抗稳定性影响的临床研究

目的：研究骨密度对正畸支抗稳定性的影响。方法：选择进行正畸治疗，需要拔除4颗第一前磨牙及弱支抗矫治的安氏Ⅰ类错牙合的健康男性患者212名，年龄18-25周岁，其中支抗失控患者16名，支抗稳定患者196名，通过双能X线骨密度仪测定每位患者4颗第二前磨牙根尖区周围0.5 cm2范围区域的骨密度，并运用统计学方法进行对比分析。结果：经单因素方差分析，两组患者第二前磨牙区域骨密度值具有显著性差异（P<0.05）。结论：骨密度可能是影响正畸支抗稳定性的因素，在正畸支抗设计时应列为参考指标之一。

Clinical study of the effect of bone density on the stability of orthodontic anchorage

Objective:To study the effect of bone density on orthodontic anchorag's stability. Method:212 healthy men aged from 18 to 25 years old, with Angle class I and week orthodontic anchorage who were reguired to treat with extraction of first premolars were selected as the samples of the study. The anchorage of 16 patients became invalid and of 196 patients were stable. Dual-energe X-ray absorptiometery was used to measure the bone density in periapical 0.5 cm2 area of the second premolars. The result were analyzed statistically. Result: There was statistically significant difference (P<0.05) in the bone density of the second premolar’s periapical area by one factor analysis of variance (ANOVA) between the two groups. Conlusion:Bone density may influence the stability of the orthodontic anchorage.