Biotechnology and Craniofacial Sciences, University of Glasgow, Glasgow Dental Hospital and School, Glasgow, UK.
Int J Oral Maxillofac Surg. 2013 Nov;42(11):1488-93. doi: 10.1016/j.ijom.2013.01.026. Epub 2013 May 2.
During cone beam computed tomography (CBCT) scanning, intra-oral metallic objects may produce streak artefacts, which impair the occlusal surface of the teeth. This study aimed to determine the accuracy of replacement of the CBCT dentition with a more accurate dentition and to determine the clinical feasibility of the method. Impressions of the teeth of six cadaveric skulls with unrestored dentitions were taken and acrylic base plates constructed incorporating radiopaque registration markers. Each appliance was fitted to the skull and a CBCT performed. Impressions were taken of the dentition with the devices in situ and dental models were produced. These were CBCT-scanned and the images of the skulls and models imported into computer-aided design/computer-aided manufacturing (CAD/CAM) software and aligned on the registration markers. The occlusal surfaces of each dentition were then replaced with the occlusal image of the corresponding model. The absolute mean distance between the registration markers in the skulls and the dental models was 0.09±0.02mm, and for the dentition was 0.24±0.09mm. When the method was applied to patients, the distance between markers was 0.12±0.04mm for the maxilla and 0.16±0.02mm for the mandible. It is possible to replace the inaccurate dentition on a CBCT scan using this method and to create a composite skull which is clinically acceptable.
在锥形束 CT(CBCT)扫描过程中,口腔内的金属物体可能会产生条纹伪影,从而影响牙齿的咬合面。本研究旨在确定用更准确的牙列替代 CBCT 牙列的准确性,并确定该方法的临床可行性。对 6 具未修复牙列的尸体头颅的牙齿进行印模,并制作包含不透射线标记物的丙烯酸基托。将每个器具安装到颅骨上并进行 CBCT。在原位将器械固定在牙齿上并制取印模,制作牙模。对牙列进行 CBCT 扫描,并将颅骨和模型的图像导入计算机辅助设计/计算机辅助制造(CAD/CAM)软件中,并在标记物上对齐。然后,用相应模型的咬合图像替换每个牙列的咬合面。颅骨和牙模上的标记物之间的绝对平均距离为 0.09±0.02mm,牙列的为 0.24±0.09mm。当该方法应用于患者时,上颌的标记物之间的距离为 0.12±0.04mm,下颌的标记物之间的距离为 0.16±0.02mm。使用该方法可以替换 CBCT 扫描中不准确的牙列,并创建临床上可接受的复合颅骨。