产后哺乳大鼠正畸牙移动速率的实验研究

AN EXPERIMETAL STUDY ON THE MOVING RATE OF ORTHODONTIC TOOTH IN POSTPARTUM LACTATING RATS

目的探讨产后哺乳大鼠和妊娠大鼠正畸牙移动速率的变化，为临床正畸治疗提供依据。方法选取健康Wistar大鼠50只，其中雌性大鼠45只，6～8周龄分成未妊娠组、妊娠组、哺乳组，雌、雄鼠按2：1合笼饲养造妊娠、哺乳大鼠模型，每组按7、14、21d时间段正畸牙移动并检测同期骨密度、骨保护素。结果哺乳组胫骨骨密度低于妊娠组低于未妊娠组（P〈0．01），差异有统计学意义。哺乳组骨保护素高于妊娠组高于未妊娠组（P〈0．05），差异有统计学意义。哺乳组正畸牙移动速率大于妊娠组大于未妊娠组（P〈0．05），差异有统计学意义。结论①哺乳大鼠骨密度低于妊娠大鼠，低于未妊娠大鼠。②哺乳大鼠正畸牙移动速率在相同力时明显大于妊娠大鼠及未妊娠大鼠，且于21d最显著。

Objective To discuss the change of orthodontic tooth moving rate in postpartum lactating rats and pregnant rats, and to provide basis for clinical orthodontic treatment. Methods Fifty adult Wistar rats were selected which concluded forty- five females, all of the rats were randomly divided into three groups with fifteen rates in each group： non- pregnant group, pregnant group and lactating group. Females and males were mated 2 ： 1 to build pregnant rat and postpartum lactating rat models. Each group was divided in accordance with the tooth movement time in seven days, fourteen days and twenty- one days, while the same period of bone mineral density（BMD） and Osteoprotegerin （OPG） were detected. Results ,The tibial bone mineral density of lactating group was lower than the pregnant group and the non- pregnant group （P 〈0. 01）. The OPG of lactating group was higher than pregnant group and non - pregnant group（P〈0. 05）. The rate of orthodontic tooth movement of lactating group was larger than the pregnant group and the non- pregnant group（P〈0.05）. All the difference was statistically significant. Conclusions （1） The BMP of lactating rats is lower than the pregnant rats and non- pregnant rats. （2） In the same force times, the rate of orthodontic tooth movement of lactating rats is significantly larger than pregnant group and non- pregnant group, and in the twenty- one days, there has the most significant result.