Nkenke E, Zachow S, Benz M, Maier T, Veit K, Kramer M, Benz S, Häusler G, Neukam F Wilhelm, Lell M
Department of Oral and Maxillofacial Surgery, University of Erlangen-Nuremberg, Glückstrasse 11, 91054 Erlangen, Germany.
Dentomaxillofac Radiol. 2004 Jul;33(4):226-32. doi: 10.1259/dmfr/27071199.
To determine the limits of accuracy of fusion of optical three-dimensional (3D) imaging and computed tomography (CT) with and without metal artefacts in an experimental setting and to show the application of this hybrid system in 3D orthognathic surgery simulation.
Ten plaster casts of dental arches were subjected to a CT scan and optical 3D surface imaging. Subsequently, the first molars in the plaster casts were supplied with metal restorations, bilaterally, and new CT scans and optical surface images were assessed. The registration of the surface data of the two imaging modalities of the study models without and with metal restorations was carried out. The mean distance between the two data sets was calculated. From a patient a CT scan of the skull as well as optical 3D images of plaster casts of the dental arches were acquired. Again the two imaging modalities were registered and virtual orthognathic surgery simulation was carried out.
The mean distance between the corresponding data points of CT and optical 3D surface images was 0.1262+/-0.0301 mm and 0.2671+/-0.0580 mm, respectively, for the plaster casts without and with metal restorations. The differences between these data were statistically significant (P<0.0005). For the patient case a mean difference of 0.66+/-0.49 mm and 0.56+/-0.48 mm for mandible and maxilla, respectively, was calculated between CT and optical surface data.
The accuracy of the fusion of 3D CT surface data and optical 3D imaging is significantly reduced by metal artefacts. However, it seems appropriate for virtual orthognathic surgery simulation, as post-operative orthodontics are performed frequently.
在实验环境中确定有和没有金属伪影时光学三维（3D）成像与计算机断层扫描（CT）融合的精度极限，并展示这种混合系统在三维正颌外科手术模拟中的应用。
对十个牙弓石膏模型进行CT扫描和光学3D表面成像。随后，在石膏模型的第一磨牙双侧放置金属修复体，并评估新的CT扫描和光学表面图像。对研究模型在有无金属修复体情况下的两种成像模态的表面数据进行配准。计算两个数据集之间的平均距离。从一名患者获取颅骨的CT扫描以及牙弓石膏模型的光学3D图像。再次对两种成像模态进行配准并进行虚拟正颌外科手术模拟。
对于没有和有金属修复体的石膏模型，CT与光学3D表面图像相应数据点之间的平均距离分别为0.1262±0.0301毫米和0.2671±0.0580毫米。这些数据之间的差异具有统计学意义（P<0.0005）。对于患者病例，CT与光学表面数据之间在下颌骨和上颌骨的平均差异分别计算为0.66±0.49毫米和0.56±0.48毫米。
金属伪影会显著降低3D CT表面数据与光学3D成像融合的精度。然而，由于术后正畸经常进行，它似乎适用于虚拟正颌外科手术模拟。
