Allen K M, Hausmann E
Department of Oral Biology, State University of New York, Buffalo, USA.
J Periodontol. 1996 Dec;67(12):1317-21. doi: 10.1902/jop.1996.67.12.1317.
An aluminum wedge can be used to quantify volumetric change in crestal alveolar bone which has been identified through subtraction radiography. This study compares two methods for using an aluminum wedge for this purpose: 1) the aluminum wedge is present in both radiographs and used to determine the aluminum equivalent bone density present in the region of change for each radiograph; and 2) the aluminum wedge is present in only one radiograph and the difference image of the wedge in the subtraction image is used to calculate the aluminum equivalent change in bone density. Pairs of standardized x-rays were taken with synthetic bone chips of known weights placed when the second x-ray was taken. The volumetric change produced by the bone chips was calculated by the two methods. The relationship of the calculated volumes to the chip weights had a higher r2 value (P < 0.05) for the two-wedge method than for the one-wedge method. The two-wedge method is recommended for volumetric quantification of alveolar bone change. The influence of the clarity of the aluminum wedge image in the x-ray pairs was also examined in this study and found to be significant. Attention must be given to factors which affect the aluminum wedge image characteristics to achieve optimal results.
铝楔可用于量化通过减影放射成像识别出的牙槽嵴顶骨的体积变化。本研究比较了为此目的使用铝楔的两种方法：1）铝楔存在于两张放射片中，并用于确定每张放射片变化区域中存在的铝等效骨密度；2）铝楔仅存在于一张放射片中，且减法图像中楔的差异图像用于计算骨密度的铝等效变化。在拍摄第二张X线片时放置已知重量的合成骨碎片，拍摄成对的标准化X线片。通过两种方法计算骨碎片产生的体积变化。对于双楔法，计算体积与碎片重量的关系的r2值高于单楔法（P < 0.05）。推荐使用双楔法进行牙槽骨变化的体积定量分析。本研究还检查了X线对中铝楔图像清晰度的影响，发现其具有显著性。必须注意影响铝楔图像特征的因素，以获得最佳结果。
