Practical Panoramic Imaging
X-ray Source and Other Factors

Intraoral x-ray units have a round or rectangular x-ray collimator with the projected beam being slightly larger than the intraoral receptor. In comparison, panoramic x-ray units have a narrow vertical slit aperture. With intraoral x-ray units, the vertical and horizontal angle of the PID (position indicating device) is adjusted for each projection and centered over the image receptor. The panoramic x-ray tubehead is fixed at a negative angle (approximately -10°) and rotates behind the patient’s head during the exposure cycle.