正畸牙移动过程中牙槽骨局部Ca/P比值的动态分析

Changes of Ca/P ratio in alveolar bone during orthodontic treatment in rats

目的 :通过在大鼠上颌第一磨牙施加正畸力 ,研究加力后不同时期牙槽骨局部Ca/P比值的动态变化 ,以期从元素变化的角度揭示正畸牙齿移动的规律 .方法 :利用X射线能量衍射微区分析法 ,改进的冷冻断裂技术和峰背比计量技术 ,进行大鼠上颌第一磨牙局部牙槽骨中Ca、P元素含量 2 8d内动态检测 .结果 :加力后 7d ,大鼠牙槽骨标本张力侧Ca/P比值从 (2 .4 3± 0 .6 1)降至 (0 .86± 0 .10 ) ,压力侧Ca/P比值从(2 .5 8± 0 .77)降至 (0 .88± 0 .0 6 ) ;尔后张力侧Ca/P比值逐渐升高 ,到 2 8d已升至 (1.88± 0 .2 5 ) ;压力侧于加力后 14dCa/P比值为 (0 .80± 0 .13) ,显著低于张力侧同期水平 (P <0 .0 1) ,然后逐渐升高 ,到 2 8d升至 (1.79± 0 .30 ) .结论 :加力后局部牙槽骨的改建呈现出动态变化的过程 .张力侧及压力侧 ,其Ca/P比值分别发生变化 ,并在

AIM: To investigate the tooth movement by detecting the changes of Ca/P ratio during orthodontic treatment of SD rats' maxillary first molars. METHODS: Calcium and phosphine concentrations were observed from 1 to 28 days during orthodontic movement by X ray energy dispersive system (EDS), modified frozen section technique and peak background comparison method. RESULTS: Up to the 6th day of the tooth loading, the Ca/P ratio of rat alveolar bone in the tension region decreased from 2.43±0.61 to 0.86±0.10 while in the pressure region from 2.58±0.77 to 0.88±0.06. Beginning from the 7th day and to the 28th day, the Ca/P ratio in the tension region increased gradually to 1.88±0.25. Ca/P ratio the pressure region was significantly lower than that in the tension region at 14th day ( P <0.01) and its ratio enhanced and reached 1.79±0.30 at 28th day. CONCLUSION: Changes of Ca/P ratio are different in the tension region and the pressure region and a new balance may be achieved at about 1 month after the operation.