Section of Maxillofacial Orthognathics, Department of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan.
Angle Orthod. 2012 Mar;82(2):284-93. doi: 10.2319/033111-231.1. Epub 2011 Aug 17.
To develop surgical stents for cone-beam computed tomography (CBCT) 3-dimensional (3D) image-based stent-guided orthodontic miniscrew implantation and to evaluate its accuracy.
Ten surgical stents were fabricated with stereolithographic appliances (SLAs) according to 3D CBCT image-based virtual implantation plans. Thirty self-drilling miniscrews were implanted at two to three positions on each side of the maxillary or mandibular posterior arches in three phantoms: 20 guided by 10 surgical stents in two phantoms (stent group) and 10 guided freehand in one phantom (freehand group). Six parameters (mesiodistal and vertical deviations at the corona and apex and mesiodistal and vertical angular deviations) were measured to compare variations between the groups.
No root damage was found in the stent group, whereas four of 10 miniscrews contacted with roots in the freehand group. In the stent group, deviations in the mesiodistal and vertical directions were 0.15 ± 0.09 and 0.19 ± 0.19 mm at the corona, respectively, and 0.28 ± 0.23 and 0.33 ± 0.25 mm at the apex, respectively; angular deviations in the mesiodistal and vertical directions were 1.47° ± 0.92° and 2.13° ± 1.48°, respectively. In the freehand group, the corresponding results were 0.48 ± 0.46 mm and 0.94 ± 0.87 mm (corona), 0.81 ± 0.61 mm and 0.78 ± 0.49 mm (apex), and 7.49° ± 6.09° and 6.31° ± 3.82°. Significant differences were found in all six parameters between the two groups (Student's t-test, P < .05).
3D CBCT image-based SLA-fabricated surgical stents can provide a safe and accurate method for miniscrew implantation.
开发基于锥形束计算机断层扫描（CBCT）三维（3D）图像的外科支架，用于基于支架引导的正畸微螺钉植入，并评估其准确性。
根据基于 3D CBCT 图像的虚拟植入计划，使用立体光造型设备（SLA）制作了 10 个外科支架。在三个模型中，在每个上颌或下颌后牙弓的两个至三个位置植入 30 个自攻微螺钉：两个模型中使用 10 个外科支架引导 20 个微螺钉（支架组），一个模型中徒手引导 10 个微螺钉（徒手组）。测量 6 个参数（牙冠和根尖的近远中及垂直偏差，以及近远中及垂直角度偏差），比较两组之间的差异。
支架组未发现根损伤，而徒手组的 10 个微螺钉中有 4 个接触根。在支架组，牙冠处的近远中和垂直偏差分别为 0.15±0.09 和 0.19±0.19mm，根尖处分别为 0.28±0.23 和 0.33±0.25mm；近远中和垂直方向的角度偏差分别为 1.47°±0.92°和 2.13°±1.48°。在徒手组，相应的结果分别为 0.48±0.46mm 和 0.94±0.87mm（牙冠），0.81±0.61mm 和 0.78±0.49mm（根尖），7.49°±6.09°和 6.31°±3.82°。两组之间的所有 6 个参数均有显著差异（Student's t 检验，P<.05）。
基于 3D CBCT 图像的 SLA 制作的外科支架可为微螺钉植入提供安全准确的方法。
