Improvement of diagnostic performance by using grid on anterior maxillary axial occulisal projection

Abstract

Anterior maxillary axial occulusal projection is a significant method to visualize anatomical locations of supernumerary, unerupted, and impacted teeth, foreign bodies and the lesions in the anterior maxilla exactly. The purpose of this study is to review the exposure conditions of the conventional anterior maxillary axial occulusal projection and to evaluate the diagnostic performances of the radiograms with a grid and without a grid.

Fuji RX films (screen type) were used with a screen (Kyokko, PS-II), with screen and grid, and without screen and grid. Radiograms of the test chart were performed with these films using a screen with a grid and without a grid under the same exposure conditions. Radiograms of the maxilla of Rando phantom (Alderson Co.) were performed with Fuji RX films using a screen and agrid on tube potential 60 kV, 70 and 80 respectively. Anterior maxillary axial occulusal projections of a patient were performed using the same screen system with a grid and without a grid by dental X-ray exposure unit. All of the radiograms obtained were evaluated for the diagnostic performances by 9 radiological stuffs.

No significant differences of diagnostic performances among radiograms performed on 60,70 and 80kV are exhibited. Radiogram of a patient with a grid has better diagnostic performances than that of without a grid. The results suggested that the application of a grid with screen system is useful to the anterior maxillary axial occulusal projection. For the reduction of dose to patients, dental X-ray unit with variable tube potential is recomended to the projection.