Radiographs are an integral component of a periodontal assessment for those with clinical evidence of periodontal destruction. A close consideration of the current approach to periodontal diagnosis compatible with the current classification of periodontal diseases reveals that radiographs only inform with respect to diagnosis for a small proportion of conditions. The area in periodontal assessment in which radiographs play a pivotal role is in treatment planning. A variety of radiographic exposure types assist in the development of periodontal treatment plans. This "therapeutic yield" can be achieved by panoramic oral radiographs supplemented by selective intra-oral views. Digital panoramic oral radiographs viewed on screen appear to offer advantages over printouts or films. Newer imaging approaches, such as cone-beam computed (digital volume) tomography, may come to show some usefulness but experience has shown that digital subtraction radiography will probably remain a research tool without much clinical application.