Extra Oral Radiology

Question 0

Reasons for extra oral films that are not supplemental

Answer 0

When swelling or injury makes film placement impossible

When a child cannot tolerate films intra orally

Question 1

Extra oral rule

Answer 1

Extra oral films do not show clarity of teeth and bone levels for interprovincial decay and fine diagnostic problems as well as periodontal problems

Question 2

Extra oral films show the following:

Answer 2

Large portions of the maxilla or mandible
Complete posterioanterior view of the skull
Facial profile
View of the sinuses
TMJ

Question 3

Extra oral films valuable to

Answer 3

Oral surgeon
Orthodontist
Prosthodontist

Question 4

Handheld technique

Answer 4

Posterioanterior with lateral jaw survey- provides an overview of facial bones and jaw structures. Helpful to the oral surgeon in determining the extent of fractures, bone diseases, malignancies, presence of foreign bodies.

Question 5

TMJ radiograph

Answer 5

Checks the shape of the condyle-essential in determining the extent of damage caused by tooth loss, injuries, localized disease and occlusal trauma.

Question 6

Tomography

Answer 6

Imaging technique that allows the imaging of one layer, or section, of the body while blurring the images of structures in other planes

Question 7

Lateral jaw imaging

Answer 7

Used to examine the posterior region of the mandible, valuable for children, pts with limited jaw opening, and pts who have difficulty stabilizing intra oral receptors

Question 8

Two techniques for lateral jaw imaging

Answer 8

Body of mandible

Ramus of mandible

Question 9

Body of mandible technique used to

Answer 9

Evaluate impacted teeth, fractures, and lesions located in the body if the mandible

Question 10

Ramus of mandible technique used to

Answer 10

Evaluate impacted third molars, large lesions, and fractures that extend into the ramus of the
Mandible

Question 11

Lateral cephalometric projection

Answer 11

Evaluates facial growth and development, trauma, and disease and development abnormalities

Question 12

Posteroanterior projection

Answer 12

Demonstrates frontal and ethmoid sinuses, the orbits, and nasal cavity

Question 13

Two techniques in TMJ imaging

Answer 13

Transcranial projection

TMJ tomography

Question 14

Cephalometric radiography includes

Answer 14

Posteroanterior and lateral radiographs

Question 15

Cephalometric radiography will show:

Answer 15

Anatomy of the jaw, growth and development of the dentition, record of changes produced by orthodontic treatment

Question 16

Cephalometrics

Answer 16

Measurements of pts head

Question 17

Anthropometry

Answer 17

Science that deals with measurements of the size, weight and proportions of human body

Question 18

Cephalometer

Answer 18

Is a device used to standardize the placement of the head during exposure

Question 19

Craniostats or cephalostat

Answer 19

Used to stabilize the patient head parallel to the film at right angles to the direction of the beam of radiation

Question 20

TFD

Answer 20

5 feet

Question 21

Disadvantages of panoramic exposures

Answer 21

Cannot detect height of alveolar bone and inter proximal decay for diagnostic purposes
Varying degree of magnification, distortion, and definition as well as overlapping because it is exposed outside of patients mouth

Question 22

Panoramic exposures advantage

Answer 22

To detect pathology that cannot be seen on intra oral radiographs
Radiation dose is relatively low

Question 23

Radiation exposure

Answer 23

20 seconds .8R of radiation

Question 24

Horizontal plane

Answer 24

At the center of rotation, xray beam passes the center of rotation in a horizontal plane

Question 25

Vertical plane

Answer 25

Located at the target in the tube head; the moving X-ray beam passes through the patient head

Question 26

Focal trough

Answer 26

Theoretical concept to determine where the dental arches, the sinuses, or other areas should be positioned in order to achieve the clearest image