Lifshitz Abraham B, Muñoz Mónica
Department of Orthodontics, College of Dental Medicine, Nova Southeastern University, Fort Lauderdale, Florida 33328, USA.
World J Orthod. 2010 Winter;11(4):352-6.
To evaluate the stability of self-drilling mini-implants used for immediate en masse retraction of all anterior teeth.
Six patients with 12 self-drilling mini-implants (diameter 1.6 mm, length 6.0 mm), which were placed on each side between the maxillary first molar and second premolar, were evaluated. The mini-implants were loaded immediately after placement with a force of 200 cN. Lateral cephalograms were taken upon loading (T1) and after 6 months of retraction (T2). All T1 and T2 radiographs were analyzed by localizing the anterior border of the mini-implant heads. Their vertical displacement was measured in millimeters to the Frankfort plane; the horizontal displacement was measured to a line perpendicular to the Frankfort plane registered at sella.
Analysis of variance revealed a significant difference for the horizontal (P<.05) but not for the vertical pre- and posttreatment position.
Mini-implants provide good anchorage for the retraction of teeth. However, the self-drilling mini-implants used in this study did not remain absolutely stationary like osseointegrated implants. With loading, they moved in the direction of the applied force, but their displacement had no clinical impact.
评估用于即刻整体内收所有前牙的自攻型微型种植体的稳定性。
对6例患者进行评估，在上颌第一磨牙和第二前磨牙之间的每侧植入12枚自攻型微型种植体（直径1.6 mm，长度6.0 mm）。种植体植入后立即施加200 cN的力。在加载时（T1）和内收6个月后（T2）拍摄头颅侧位片。通过定位微型种植体头部的前缘对所有T1和T2 X线片进行分析。测量其相对于法兰克福平面的垂直位移（以毫米为单位）；测量相对于在蝶鞍处记录的与法兰克福平面垂直的线的水平位移。
方差分析显示，治疗前后水平位移有显著差异（P<0.05），但垂直位移无显著差异。
微型种植体为牙齿内收提供了良好的支抗。然而，本研究中使用的自攻型微型种植体并不像骨结合种植体那样绝对固定。加载后，它们沿施力方向移动，但其位移无临床影响。
