Steinvorth Benjamin, Troiani Stefano, Weir Tony, Meade Maurice J
YOUniquehorns GmbH, Ulm, Germany.
Private Practice, Zurich, Switzerland.
Orthod Craniofac Res. 2025 Feb;28(1):75-83. doi: 10.1111/ocr.12848. Epub 2024 Aug 27.
The aim of the current study was to develop and describe a new measuring system for the orientation of a tooth in a digitalized cast of a jaw and provide new angular values for the rotation, torque and tip of maxillary and mandibular teeth.
This retrospective cross-sectional study involved the utilization of a sub-group of extrinsic Euler-angles to derive optimal norm values per tooth in three different planes of orientation ('rotation', 'torque' and 'tip') by evaluating the digital representations of the teeth derived from a database containing over 17,500 patients. The process involved the entry of the .stl files of the jaw pairs into a fully automated software system (Smyl:Ai, Ulm, Germany) whereupon jaw alignment, teeth segmentation, landmark identification and visual validation of input files was conducted prior to calculation of the norm values for the three different planes of orientation.
The digital scans in stereolithography (.STL)-file format of the upper and lower dentitions of 1914 individuals with optimal occlusion were chosen and evaluated. New mean (standard deviation) angular values were determined for the rotation, torque and tip of maxillary and mandibular teeth.
The findings facilitate the reappraisal of rotation, torque and tip values currently acceptable as ideal. They will inform anthropologists and dental researchers about occlusion and alignment in orthodontic and non-orthodontic patients and provide baseline data for future studies. The methodology will also enable the evaluation of large numbers of data in relatively short timeframes.
本研究的目的是开发并描述一种用于在数字化颌骨模型中确定牙齿方位的新测量系统，并为上颌和下颌牙齿的旋转、转矩和倾斜提供新的角度值。
这项回顾性横断面研究利用一组外在欧拉角，通过评估来自一个包含超过17500名患者的数据库中的牙齿数字表示，在三个不同的方位平面（“旋转”、“转矩”和“倾斜”）中得出每颗牙齿的最佳标准值。该过程包括将颌骨对的.stl文件输入到一个全自动软件系统（Smyl:Ai，德国乌尔姆）中，然后在计算三个不同方位平面的标准值之前，进行颌骨对齐、牙齿分割、地标识别和输入文件的视觉验证。
选择并评估了1914名具有最佳咬合的个体的上下牙列的立体光刻（.STL）文件格式的数字扫描。确定了上颌和下颌牙齿的旋转、转矩和倾斜的新平均（标准差）角度值。
这些发现有助于重新评估目前被认为是理想的旋转、转矩和倾斜值。它们将告知人类学家和牙科研究人员正畸和非正畸患者的咬合和对齐情况，并为未来的研究提供基线数据。该方法还将能够在相对较短的时间内评估大量数据。
