Division of Orthodontics and Dentofacial Orthopedics, Graduate School of Dentistry, Tohoku University, Sendai, Japan.
Am J Orthod Dentofacial Orthop. 2013 Aug;144(2):251-9. doi: 10.1016/j.ajodo.2013.03.021.
The purpose of this article was to test the theory that short miniscrews will decrease the possibility of damaging the root, but the failure rate will increase.
One hundred eighty-six miniscrews (diameter, 1.3 × 5 mm, n = 63; 6 mm, n = 62; 7 mm, n = 61) were placed in 105 consecutive patients. Multislice computed tomography and cone-beam computed tomography scans were taken before and after miniscrew placement. Insertion torque was measured at miniscrew placement.
The success rate of the miniscrews in the maxilla (93.4%) was higher than that in the mandible (70.3%). A significantly lower success rate with 5-mm miniscrews was observed compared with 6-mm and 7-mm miniscrews in the mandible. Miniscrews placed in less than approximately 3.8 mm of bone and those within 1.4 mm of the root had significantly higher failure rates. Miniscrews placed with insertion torque greater than 10 Ncm had a tendency for a lower success rate.
The optimum lengths of miniscrews of a diameter of 1.3 mm are 5 mm in the maxilla and 6 mm in the mandible. They should be placed at a distance from the root with insertion torque less than 10 Ncm for safe orthodontic anchorage without failure.
本文旨在验证一个理论，即短微型种植体将降低损伤牙根的可能性，但失败率会增加。
将 186 颗微型种植体（直径 1.3×5mm，n=63；6mm，n=62；7mm，n=61）植入 105 名连续患者中。在微型种植体植入前后进行多层螺旋 CT 和锥形束 CT 扫描。测量微型种植体植入时的插入扭矩。
上颌微型种植体的成功率（93.4%）高于下颌（70.3%）。与下颌 6mm 和 7mm 微型种植体相比，5mm 微型种植体的成功率明显较低。植入骨深度小于约 3.8mm 和距离牙根 1.4mm 以内的微型种植体失败率显著较高。插入扭矩大于 10Ncm 的微型种植体成功率有降低的趋势。
直径 1.3mm 的微型种植体最佳长度为上颌 5mm 和下颌 6mm。为了安全的正畸锚固而不失败，应在距离牙根有一定距离处，使用插入扭矩小于 10Ncm 的微型种植体。
