dental

What is the function of the cathode?

Produces electrons by thermionic emission

• made of tungsten and focusing cup

What is the function of the anode?

Converts electron energy into X-rays and heat

Intraoral Radiography

• Periapical, bitewing, and occlusal.

• Highest spatial resolution and detail.

• Periapical, bitewing, and occlusal

• Periapical- Entire tooth and surrounding periapical bone

• bitewing- Crowns of upper and lower teeth and alveolar crest.

• occlusal- Shows a large area of the maxilla or mandible, including teeth, supporting bone, and adjacent structures, on a single image.

Which modality has the smallest field?

intraoral. small field round collimation of
approximately 6 cm

rotating/fixed tube

rotating: ConeBeam CT, OPG

Fixed tube: Intraoral, lertal ceph

cone beam CT

Largest FOV

3D images

rotating tube

• disadvantage: dose and cost

What material is commonly used as added filtration?

A: Aluminium

Lateral Cephalogram

• long source-to-image distance to minimise magnification

• facilitate distance and angle
  measurements for orthodontic
  treatment and diagnosis

opg

• The X-ray tube and detector rotate around the patient

• focal trough?
  A: The image layer where structures appear sharp.

opg too far forward or back

• forward- Anterior teeth appear narrow

• back- Anterior teeth appear widened