Subjective Image Quality of Lateral Cephalometric Radiographs With and Without Application of a Prediction Model

Objective: A prediction model was developed to simulate an underexposed radiograph to that which is optimally exposed. The objective of the study was to evaluate if radiographic landmarks were equally observed in lateral cephalometric radiographs processed with and without the prediction model. Methods: Using a digital imaging system (Orthopantomograph®OC-100D), test radiographs of a human skull phantom covered with simulated soft tissue were obtained using different exposure settings. The optimal radiograph was subsequently established. The under-exposed raw data radiographs were then processed in two sets. In one set, the radiographs were first simulated from the optimally exposed raw data radiograph using the prediction model and then processed with the default settings of the proprietary softwa re that was used to control the imaging system used. In the second set, the radiographs were processed only with the default settings of the proprietary softwa re. Two monitors were employed to simultaneously display the radiographs. Six observers subjectively compared the fourteen most frequently used landmarks on both radiographs. Results: Compared with the non-predicted radiographs, in the predicted radiographs subjective impression of the radiographic landmarks was more frequently considered the same or better than the optimal radiographs. The difference was statistically significant. Conclusion: The subjective impression of the landmarks in the predicted radiographs is better than that in the non-predicted radiographs. Parole chiave: cephalometry, dental radiography, digital dental radiography, image processing, radiography