Abstract:

Objective    To investigate the clinical effect of the modified transpalatal arch to vertically control the maxillary first molar. Methods    Modified transpalatal arch was used to control the maxillary first molar of 10 patients with vertical growth form the Department of Stomatology in the Fourth Affiliated Hospital of Harbin Medical University in 2012—2014. Conduct cephalometrics before and after MTPA. Statistics analysis was done. Results    Statistical data analysis showed that there was significant change in mandibular plane angle，the mesital tip of U6-PP the axial angle and the distal tip of U6-PP （all P < 0.05）；the differences of variation in the U6-SN and U6 mesiodistal displacement had no statistical significance between before and after treatment（P > 0.05）. The mestial tip of U6-PP and the distal tip of U6-PP averagedly decreased 2.75 mm and 2.5 mm respectively. Conclusion    The modified transpalatal arch can effectively bring down the maxillary first molar.

Key words: orthodontic；modified transpalatal arch, MTPA；maxillary first molar；vertical control； cephalometric

摘要：

目的    探讨改良式横腭杆（MTPA）对上颌第一磨牙垂直向控制的临床效果。 方法    选择2012——2014年在哈尔滨医科大学附属第四医院口腔科就诊的10例垂直生长型患者，应用MTPA压低上颌第一磨牙，治疗前后进行头影测量，并进行统计学分析。结果    使用MTPA后，下颌平面角、U6近中尖-PP、面轴角、U6远中尖-PP均有明显变化（均P < 0.05），其中U6近中尖-PP、U6远中尖-PP的距离分别平均减小2.75和2.50 mm。U6-SN、U6近远中移位无明显变化（P > 0.05）。结论    MTPA可有效压低上颌第一磨牙。

关键词: 正畸, 改良式横腭杆, 上颌第一磨牙 , 垂直向控制, 头影测量