大鼠动情周期不同阶段加力对正畸牙移动的影响

Influences of Applying Force during the Different Stages of Estrous Cycle on Orthodontic Tooth Movement of Rats

目的探讨在雌性大鼠动情周期不同阶段加力对正畸牙移动的影响,以期为正畸临床女性患者的治疗选择最佳介入时间提供参考。方法选取3月龄Wistar雌性大鼠80只,随机分为对照组、加力组。各组又根据所处动情周期的不同阶段分为4个亚组(动情前期、动情期、动情后期和动情间期)。加力组分别在动情周期的特定阶段给予重复的间断力4次,而后测量大鼠的左侧上颌切牙远中邻面和同侧第一磨牙近中邻面间的距离。单因素方差分析、S_N_K法进行统计分析处理。结果动情周期的不同阶段加力组的牙移动总量的差异有统计学意义(P<0.01)。组间两两比较显示:动情前期加力组和动情期加力组牙移动量的差异有统计学意义(P<0.05);动情后期加力组和动情间期加力组的差异无统计学意义(P>0.05),但它们与前两组的差异有统计学意义(P<0.05)。在动情前期加力进行牙移动,牙移动量最小;在动情期加力,则牙移动量最大。结论选择在动情周期的不同阶段进行正畸加力,所获得的牙移动效果不同。

Objective To explore the effects of applying force during the different stages of estrous cycle on orthodontic tooth movement of rats, so as to offer an experimental princinple for women＇s orthodontic treatment.Methods 80 female 3-month-old Wistar rats, which had a stable and five-day estrous cycle, were used. They were randomly divided into control groups and loading-force groups. Each group was divided again into 4 sub-groups according to the different stages of the estrous cycle. The loading-force groups received repeated intermittent orthodontic force for four times seperately during the same stage of the estrous cycle. The distance between upper incisor and the first molar on the left was measured. The data were analyzed by One-way ANOVA, S-N-K. Results There were significant variations in the amount of tooth movement among the groups which received the mechanical force during the different stages of the estrous cycle （ P 〈 0.01）. There were significant variations in the amount of tooth movement between the groups received force during pre-estrus and estrus （ P 〈 0.05）. There were not significant variations between the groups received force during metestrus and diestrus （ P 〉 0.05）. The largest amount of tooth movement was in estrus group and smallest in pre-estrus one. Conclusion The effect of tooth movement depended on which stage of estrous cycle was chosen to be the time of applying orthodontic force.