Intraoral transmission radiographs have been the primary diagnostic method for the assessment of bone support as well as for the detection and measurement of osseous changes due to periodontitis. The purpose of the present paper is three-fold. The first is to review radiographic techniques for the assessment of periodontal disease progression, presenting the strengths and weaknesses of each method while placing special emphasis on digital subtraction radiography. The second purpose is to present data from a recent study that compared the ability of digital subtraction radiography and automated attachment level probing to detect the same active sites. Thirty periodontitis patients and eight control patients were studied over a 6-month period. The results indicate that when these two sensitive methods for the assessment of progressive periodontitis were used there was concordance between the presence or absence of probing attachment loss and bone loss in 82.1% of the sites. The final goal of this paper is to present future directions for the quantitative analysis of digital radiographic images.