A comparison of rectangular and cylindrical collimation for intraoral radiographs

This study was conducted to compare the type and frequency of cone-cuts that occur with rectangular and cylindrical collimation in dental radiography. Thirty-eight hundred radiographs, half made with cylindrical cones and half made with rectangular cones, were examined for major and minor cone-cuts. A total of 156 cone-cuts was found. Thirty-three of these were of the major category, 86 percent of which occurred with rectangular collimation. Although cone-cuts appeared much more frequently when a rectangular cone was used, a significant reduction in useless radiation makes this type of collimation a worthwhile consideration.