Fig. 6

The movement and process of the central ray of the panoramic radiograph around nasal cavity is matched and marked by same number. The vertical lines of the panoramic radiography (a) and the yellow arrows of the three-dimensional image (b) shows the path through which the central ray of the X-ray beam passes at the moment. When a central ray passes through the nasal septa, it passes vertically (number 1). As the central ray moves, it passes the corner of the abduction side, the nasal pyriform aperture of the maxilla (number 2), rather than the actual lateral wall (red line)