Abstract：
OBJECTIVE: To analyze the differences in cusp height on radiographs, establishing proportional relationships between cusp and alveolar bone crest (ABC) measurements. The goal of this study was to develop a correction coefficient by considering this proportion.
METHODS: Twenty-one artificial teeth, molars and premolars, and bovine ribs were used. Interproximal radiographs were taken with the aid of a positioner. The vertical angles used were: 0°, + 5°, and + 10°, and processed using three spatial resolutions measured in line pairs per mm (lp/mm): 20, 25 and 40. The Perio filter was applied to each image, in addition to the original one. Combinations of angle, resolution, and filter were made. Eighteen images were analyzed by three specialists, resulting in 252 measurements for each evaluator, totaling 756 measurements.
RESULTS: The overall variability of the measurements can be explained mainly by the variation in tooth anatomy. The 0° 25 lp/mm Perio filter method was the closest one to the actual clinical scenario for both cusps and ABC. The correction factor managed to explain 71.45% of the errors.
CONCLUSIONS: The variation in vertical angulation interferes with cusp and ABC measurements, and the angulation at 0º and spatial resolution of 25 lp/mm showed better results. The use of correction coefficients allowed approaching actual measurement values.
CONCLUSIONS: More accurate ABC height measurements are essential even in radiographic exams that do not meet the standard of excellence because the need to repeat radiographic exams is then eliminated.
METHODS: Twenty-one artificial teeth, molars and premolars, and bovine ribs were used. Interproximal radiographs were taken with the aid of a positioner. The vertical angles used were: 0°, + 5°, and + 10°, and processed using three spatial resolutions measured in line pairs per mm (lp/mm): 20, 25 and 40. The Perio filter was applied to each image, in addition to the original one. Combinations of angle, resolution, and filter were made. Eighteen images were analyzed by three specialists, resulting in 252 measurements for each evaluator, totaling 756 measurements.
RESULTS: The overall variability of the measurements can be explained mainly by the variation in tooth anatomy. The 0° 25 lp/mm Perio filter method was the closest one to the actual clinical scenario for both cusps and ABC. The correction factor managed to explain 71.45% of the errors.
CONCLUSIONS: The variation in vertical angulation interferes with cusp and ABC measurements, and the angulation at 0º and spatial resolution of 25 lp/mm showed better results. The use of correction coefficients allowed approaching actual measurement values.
CONCLUSIONS: More accurate ABC height measurements are essential even in radiographic exams that do not meet the standard of excellence because the need to repeat radiographic exams is then eliminated.
摘要：
目的：分析射线照片上尖点高度的差异，建立牙尖和牙槽骨峰（ABC）测量值之间的比例关系。这项研究的目的是通过考虑这一比例来制定校正系数。
方法：21颗假牙，磨牙和前磨牙，使用牛肋骨。在定位器的帮助下拍摄邻间射线照片。使用的垂直角度为:0°,+5°,+10°,并且使用以每毫米(lp/mm)的线对测量的三个空间分辨率来处理:20、25和40。Perio滤波器应用于每个图像，除了原来的。角度的组合，决议,并制作了过滤器。三位专家分析了18张图像，导致每个评估者进行252次测量，总计756次测量。
结果：测量的总体变异性可以主要通过牙齿解剖结构的变化来解释。0°25lp/mmPerio滤波器方法是最接近尖端和ABC的实际临床情况的方法。修正因子能够解释71.45%的误差。
结论：垂直角度的变化会干扰尖点和ABC测量，在0º的角度和25lp/mm的空间分辨率显示出更好的结果。校正系数的使用允许接近实际测量值。
结论：即使在不符合卓越标准的射线照相检查中，更精确的ABC高度测量也是必不可少的，因为这样就消除了重复射线照相检查的需要。
方法：21颗假牙，磨牙和前磨牙，使用牛肋骨。在定位器的帮助下拍摄邻间射线照片。使用的垂直角度为:0°,+5°,+10°,并且使用以每毫米(lp/mm)的线对测量的三个空间分辨率来处理:20、25和40。Perio滤波器应用于每个图像，除了原来的。角度的组合，决议,并制作了过滤器。三位专家分析了18张图像，导致每个评估者进行252次测量，总计756次测量。
结果：测量的总体变异性可以主要通过牙齿解剖结构的变化来解释。0°25lp/mmPerio滤波器方法是最接近尖端和ABC的实际临床情况的方法。修正因子能够解释71.45%的误差。
结论：垂直角度的变化会干扰尖点和ABC测量，在0º的角度和25lp/mm的空间分辨率显示出更好的结果。校正系数的使用允许接近实际测量值。
结论：即使在不符合卓越标准的射线照相检查中，更精确的ABC高度测量也是必不可少的，因为这样就消除了重复射线照相检查的需要。
