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

Resumo

To evaluate the indirect digitization method of cephalometric radiographs in com- parison with the direct digital method. Methods: The sample was composed of ten cephalo- metric radiographs acquired by Orthopantomograph OP100/Orthocef OC100 (GE – Instru- mentarium), digital direct. In the AdobeTM 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 SonyTM DSC-W5 and CanonTM 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 PackardTM Scan Jet 4C scanner. The direct digital images and the indirect ones were inserted and gauged in the Radiocef Studio (RadiomemoryTM, Brazil) software and the center of the previously marked landmarks was set. The cephalometric com- puterized 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 ac- ceptable. At 25 cm, the cameras caused the largest distortions, being more expressive and with clinical significance in the images of CanonTM Rebel XT. Conclusions: The Hewlett PackardTM Scan Jet 4C scanner with transparency reader and the SonyTM DSC-W5 and CanonTM Rebel XT/EOS cameras operating at 60 cm were shown appropriate for the digitization of cephalo- metric radiographs. In 25 cm, the digital cameras caused distortions in the image which altered the linear measurements with possibilities of jeopardizing the orthodontic diagnosis.

Descrição

Palavras-chave

Digital dental radiography, Computer-assisted cephalometrics, Orthodontics, Radiographic image interpretation

Citação

RODRIGUES, Cleomar Donizeth et al. Evaluation of indirect methods of digitization of cephalometric radiographs in comparison with the direct digital. Dental Press Journal of Orthodontics, Maringá, v. 15, n. 4, p. 124-132, 2010.