Orthodontic Unit, Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia.
Orthodontic Unit, Adelaide Dental School, University of Adelaide, Adelaide, South Australia, Australia.
Am J Orthod Dentofacial Orthop. 2024 Oct;166(4):384-392.e2. doi: 10.1016/j.ajodo.2024.06.009. Epub 2024 Jul 23.
Research regarding orthodontic changes using the superimposition of digital study models (DSMs) is commonplace. Information regarding the accuracy of data processing by superimposition software is limited. The study aimed to compare different methods of superimposing DSMs using implant-supported crowns (ISC) as a stable reference structure.
DSMs containing ISCs were sourced from a database of patients treated with clear aligner therapy. The DSM representing the planned treatment outcome was superimposed on the pretreatment DSM. Three tooth points were selected for comparison on the contralateral side of each ISC. Differences in Cartesian coordinates for each tooth point for each arch superimposition method, used by the Geomagic Control X (3D systems, Rock Hill, NC) software system, were recorded. Paired t tests for the reference standard superimposition method best-fit high-resolution using the entire dental arch compared with initial, best-fit low-resolution, and best-fit high-resolution using the ISC only were calculated.
The DSMs of 54 dental arches containing ISCs were evaluated. All mean differences for displacements of selected points on the contralateral side to the ISC in the 3 Cartesian planes were <0.05 mm (P <0.05) and below the threshold of clinical significance. In addition, the standard superimposition techniques (initial, best-fit low-resolution, and best-fit high-resolution) resulted in nonstatistically significant and nonclinically significant differences in the position of the ISC.
Researchers can be confident that the described superimposition methodologies, with and without ISCs as a stable reference structure, are a valid method for accurately assessing most intraarch dental changes.
使用数字研究模型（DSM）叠加来研究正畸变化的研究很常见。关于叠加软件处理数据准确性的信息有限。本研究旨在比较使用种植体支持的牙冠（ISC）作为稳定参考结构的不同 DSM 叠加方法。
从接受透明矫正治疗的患者数据库中获取包含 ISC 的 DSM。将代表计划治疗结果的 DSM 叠加到预处理 DSM 上。在每个 ISC 的对侧选择三个牙点进行比较。记录 Geomagic Control X（3D 系统，罗克希尔，NC）软件系统用于每个牙弓叠加方法的每个牙点笛卡尔坐标的差异。对于参考标准叠加方法，使用整个牙弓进行最佳拟合高分辨率与初始最佳拟合低分辨率和仅使用 ISC 进行最佳拟合高分辨率进行配对 t 检验。
评估了 54 个包含 ISC 的牙弓的 DSM。ISC 对侧三个笛卡尔平面上选定点的所有平均位移差异均<0.05 毫米（P<0.05），低于临床意义的阈值。此外，标准叠加技术（初始、最佳拟合低分辨率和最佳拟合高分辨率）在 ISC 位置上没有产生统计学上显著和临床上显著的差异。
研究人员可以相信，所描述的叠加方法，无论是否将 ISC 作为稳定的参考结构，都是准确评估大多数牙弓内牙齿变化的有效方法。
