Evaluation of indirect methods of digitization of cephalometric radiographs in comparison with the direct digital method

Cleomar Donizeth RODRIGUES, Márcia Maria Fonseca da SILVEIRA, Orivaldo TAVANO, Ronaldo Henrique SHIBUYA, Giovanni MODESTO, Carlos ESTRELA

Objective: To evaluate the indirect digitization method of cephalometric radiographs in comparison with the direct digital method. Methods: The sample was composed of ten cephalometric radiographs acquired by Orthopantomograph OP100/Orthocef OC100 (GE – Instrumentarium), digital direct. In the Adobe™ Photoshop program, five cephalometric landmarks were set in the images and the impression in transparencies was made. The indirect digitization of the images was performed through the Sony™ DSC-W5 and Canon™ Rebel XT/EOS 350D digital photographic cameras—fixed in a copy stand, at the distances of 25 cm and 60 cm—and through the Hewlett Packard™ Scan Jet 4C scanner. The direct digital images and the indirect ones were inserted and gauged in the Radiocef Studio (Radiomemory™, Brazil) software and the center of the previously marked landmarks was set. The cephalometric computerized analysis generated three angular measurements and four linear ones which were submitted to statistical analysis. Results: The images from the scanner demonstrated small statistically significant alterations, without clinical significance. When digitizing the radiographs at 60 cm, both cameras caused distortions which were statistically significant, but clinically acceptable. At 25 cm, the cameras caused the largest distortions, being more expressive and with clinical significance in the images of Canon™ Rebel XT. Conclusions: The Hewlett Packard™ Scan Jet 4C scanner with transparency reader and the Sony™ DSC-W5 and Canon™ Rebel XT/EOS cameras operating at 60 cm were shown appropriate for the digitization of cephalometric radiographs. In 25 cm, the digital cameras caused distortions in the image which altered the linear measurements with possibilities of jeopardizing the orthodontic diagnosis.

Keywords: Digital dental radiography. Orthodontics. Radiographic image interpretation. Computer-assisted cephalometrics.

Saturday, November 23, 2024 02:17