Wehrbein Heinrich, Göllner Peter
Orthodontic Clinic, University Hospital, Johannes Gutenberg-University, Mainz, Germany.
Am J Orthod Dentofacial Orthop. 2009 Nov;136(5):695-9. doi: 10.1016/j.ajodo.2007.10.050.
The aim of this study was to determine the positional stability and success rate of palatally placed length-reduced temporary anchorage devices (LRTADs) (length, 4 or 6 mm).
Twenty-two patients (ages, 21-62 years; 14 women, 8 men) were enrolled in the study. Each received 1 LRTAD (Orthosystem, Straumann, Switzerland) placed in the midsagittal palate for multifunctional anchorage tasks. Standardized cephalograms were taken directly after implant placement and at the end of treatment to analyze any implant movements. The cephalometric tracings were superimposed on anterior nasal spine to posterior nasal spine in posterior nasal spine to analyze changes in implant angulation and position during treatment. The LRTADs were also evaluated clinically for mobility.
Two of 22 implants showed mobility during the healing period (first 10-12 weeks after placement). Thus, the success rate was 91%. The remaining 20 palatally placed LRTADs had no mobility during healing (10-12 weeks) or the loading period (18 months 1 week) and were evaluated radiographically. The mean differences between the initial and final cephalometric evaluations (n = 20) were 0.5 degrees for changes in implant angulation and -0.6 mm for changes in implant position. These changes were most likely due to inaccuracies in cephalometric landmark identification rather than to LRTAD movements because no mobility was recorded.
One palatally placed LRTAD was sufficient for multifunctional stationary anchorage tasks in the maxilla under clinical loading conditions. The success rate was 91%. Implant loss occurred during the healing period.
本研究的目的是确定腭部放置的长度缩短型临时锚固装置（LRTADs）（长度为4或6毫米）的位置稳定性和成功率。
22名患者（年龄21 - 62岁；女性14名，男性8名）纳入本研究。每位患者接受1枚放置于腭中缝的LRTAD（瑞士士卓曼公司的Orthosystem），用于多功能锚固任务。在种植体植入后及治疗结束时直接拍摄标准化头颅侧位片，以分析种植体的任何移动情况。将头颅侧位片描图叠加于后鼻棘的前鼻棘至后鼻棘上，以分析治疗期间种植体角度和位置的变化。还对LRTADs进行临床松动度评估。
22枚种植体中有2枚在愈合期（植入后最初10 - 12周）出现松动。因此，成功率为91%。其余20枚腭部放置的LRTADs在愈合期（10 - 12周）或加载期（18个月1周）均无松动，并进行了影像学评估。20例患者头颅侧位测量初始与最终评估的平均差异为：种植体角度变化0.5度，种植体位置变化 - 0.6毫米。这些变化很可能是由于头颅侧位标志点识别不准确，而非LRTAD移动，因为未记录到松动情况。
在临床加载条件下，一枚腭部放置的LRTAD足以满足上颌骨多功能固定锚固任务。成功率为91%。种植体在愈合期出现丢失。
