局部应用前列腺素E_2促进兔牙弓扩大的研究

Effects of local administration of prostaglandin E_2 on the expansionof rabbit dental arch

目的：确定兔下颌中缝区注射前列腺素Ｅ＿２（ＰＧＥ＿２）是否能加快兔牙弓扩大．方法：实验期１４ｄ，矫治器应用环圈簧，同时在兔的下颌中缝区，每周２次注射ＰＧＥ＿２０．５ｍｌ（含ＰＧＥ＿２５０μｇ）．实验设计分为３组：正常组、正畸对照组和实验组。后２组兔牙施力２４５．３ｍＮ（２５ｇ），每周加力１次。结果：对照组和实验组下颌中切牙之间的距离平均是２．０５ｍｍ和３．１０ｍｍ。经统计学分析相差非常显著（Ｐ＜０．０１）．组织学观察，破骨细胞的数量和Ｈｏｗｓｈｉｐ’ｓ骨吸收陷窝的数量有明显增多，沿着骨缝两侧边缘骨吸收也很活跃．结论：ＰＧＥ＿２不仅能加速牙齿移动，而且还有加速扩弓的作用．

Objective:To investigate whether the expansion of rabbit dental arch can be sped up by injectionof prostaglandin E_2(PGE_2)into rabbit mandibular mid-suture. Methods :During 14-day expansion with heli-cal springs across the mandibular incisors,PGE_2 was administered(0.5 ml each time)containing 50μg PGE_2to rabbit mandibular mid-suture region. In this study were designed 3 groups :normal group,orthodonticcontrol group and experimental group. On the rabbit teeth of the latter 2 groups was imposed a force of 245.3 mN once a week.Results :The average distances between mandibular middle incisors in control and experi-mental groups were 2.05 mm and 3.10 mm respectively.Statistical analysis showed a significant difference(P<0.01).Histological observation demonstrated a marked increase of the member of osteoclasts andHowship’s bone lacunae. A dynamic bone resorption along the two edges of mandibular suture occurred.Conclusion :PGE_2 can not only promote tooth movement,also speed up the expansion of dental arch.