Kiliç A R, Efeoglu E, Yilmaz S
Department of Periodontology, Faculty of Dentistry, Marmara University, Nisantasi-Istanbul, Turkey.
Periodontal Clin Investig. 1996 Fall;18(2):20-6.
Standardization of intraoral radiographs is necessary for longitudinal studies of alveolar bone changes. Several methods of standardizing have been developed. These all involve fixing the geometric relations between the object, the x-ray tube, and the film. This usually involves a film holder, mounted on an occlusal stent and connected to the x-ray tube via an adapter ring. There is, however, a problem of compatibility between various commercial adapter rings and film holder assemblies. In an attempt to overcome this problem, we developed a method of producing cast acrylic adapters by making a plaster cast from a silicon rubber impression of the x-ray tube. The adapter was devised so that radiographs could be taken of all four segments using the same standard commercially available film holder. A total of 128 radiographs were taken from 42 patients who underwent various types of periodontal surgery; 64 were taken preoperatively and 64 at 6 months postoperatively. These pairs were superposed and approximately 58% were found by qualitative inspection to show total matching of geometric outlines as well as maintenance of position on the film, and approximately 73% to show geometric matching. Changes in alveolar bone height were evaluated for 11 of these totally matching pairs by counting millimetric grids and by a computer-based indirect digital imaging system. These were found to correlate satisfactorily (r = .63).
口腔内X光片的标准化对于牙槽骨变化的纵向研究是必要的。已经开发出几种标准化方法。这些方法都涉及固定物体、X射线管和胶片之间的几何关系。这通常需要一个胶片夹，安装在咬合支架上，并通过转接环与X射线管相连。然而，各种商业转接环和胶片夹组件之间存在兼容性问题。为了克服这个问题，我们开发了一种通过用X射线管的硅橡胶印模制作石膏模型来生产铸造丙烯酸转接器的方法。设计该转接器的目的是使用相同的标准商用胶片夹对所有四个牙段进行X光片拍摄。对42名接受各种类型牙周手术的患者共拍摄了128张X光片；术前拍摄64张，术后6个月拍摄64张。将这些成对的片子叠加，通过定性检查发现，约58%的片子显示几何轮廓完全匹配以及在胶片上的位置保持一致，约73%的片子显示几何匹配。通过计算毫米网格并使用基于计算机的间接数字成像系统，对其中11对完全匹配的片子评估牙槽骨高度的变化。发现这些结果具有令人满意的相关性（r = 0.63）。
