Computer-assisted Diagnosis and Monitoring of Periodontal Diseases

In the diagnosis of periodontal diseases, Digital Subtraction Radiography (DSR) is often used. A pair of dental radiographs is taken a few months apart. The difference between the two radiographs can be used as a basis for diagnosis. Even though the radiographs are in digital form, the alignment process to ensure an exact match between the two radiographs is done manually. Furthermore, there would be mismatch in exposure that affects the substraction and hence diagnosis results. The mismatch is simply ignored in the manual process. We propose a DSR system with computer-assisted alignment; and exposure compensation. In this paper, we focus on the exposure compensation technique that is based on the modified Generalized Fuzzy Operator and least squares method.