Panoramic Radiographs

Question 1

The following are indications for _______
▪ Overall evaluation of dentition
▪ Intraosseous pathology (cysts, tumors, infections,
etc)
▪ Gross evaluation of the temporomandibular joints
▪ Evaluation of position of impacted teeth (3rd molars)
▪ Evaluation of dental development and eruption
▪ Dentomaxillofacial trauma
▪ Developmental disturbances of the maxillofacial
skeleton

Answer 1

Panoramic

Question 2

Advantages of ______
1. Relatively low radiation dose
2. Broad coverage of facial bones and teeth
3. Easier technique
4. Can be used in patients with trismus or in
patients who cannot tolerate intraoral
radiographs
5. Quick and convenient radiographic
technique
6. Useful visual aid in patient education

Answer 2

Panoramic imaging

Question 3

Disadvantages of \_\_\_\_\_\_\_:
1. Lower-resolution images (no possible
to detect small carious lesions or early
periapical disease)
2. Overlap in the premolar area
3. Magnification across image is unequal,
making linear measurements unreliable
4. Image is superimposition of real,
double, and ghost images
5. Requires accurate patient positioning to
avoid positioning errors and artifacts
6. Difficult to image both jaws when
patient has severe maxillomandibular
discrepancy

Answer 3

Panoramic

Question 4

Orange Star?

Answer 4

Light localizer with height adjustment (Frankfurt horizontal plane)

Question 5

Blue star?

Answer 5

Light localizer central light beam for face center (Sagittal)

Question 6

Green star?

Answer 6

Forehead support

Question 7

Brown star?

Answer 7

Temple supports

Question 8

Purple star

Answer 8

Senspr

Question 9

Red star?

Answer 9

Primary diagphragm field onn the xray tube assemble

Question 10

Gray star?

Answer 10

Bite block; contact segment or chin rest

Question 11

Yellow star?

Answer 11

Handle for patient

Question 12

How many collimators are on the panoramic xray apparatus?

Answer 12

2

Question 13

Which side of the head does the xray tube start on?

Answer 13

Right side

Question 14

Does the xray source ever pass in front of pt?

Answer 14

No

Question 15

Does the receptor pass in front of pt?

Answer 15

Yes

Question 16

Which side of the mouth is imaged first?

Answer 16

Left side

Question 17

▪ A three-dimensional curved zone in which structures are
reasonably well defined.
▪ Is where dental arches must be positioned to achieve
sharpest images
▪ Objects outside are blurred, magnified, or
reduced in size and are sometimes distorted to the extent of
not being recognizable.
▪ Structures positioned in the center are the
clearest and those that are progressively farther from the
center of the focal trough become progressively less clear

Answer 17

Focal trough

Question 18

Is there one center of rotation on a pano?

Answer 18

No; multiple for even sharpness in focal trough

Question 19

Objects closer to the receptor will be _____

Answer 19

narrowed

Question 20

Objects closer to the source will be ______

Answer 20

widened

Question 21

Buccal objects will be projected ______

Answer 21

lower

Question 22

Lingual objects are projected ______

Answer 22

higher

Question 23

▪ Approximately -4 degrees, to avoid projection
of the occipital bone
▪ Structures closer to the source are projected
higher up on the image, relative to structures
that are positioned farther away from the
source
▪ Spatial relationships between the objects in the
vertical dimension may not accurate*
▪ Distance between the root apex and the
mandibular canal can be misrepresented on a
panoramic radiograph.

Answer 23

Beam angulation

Question 24

If an object is ____ to the focal trough, the beam velocity is slower creating a larger image

Answer 24

Lingual

Question 25

If an object is ____ to the focal trough, the beam velocity is faster creating a smaller image

Answer 25

Buccal

Question 26

Is the distortion worse in the anterior or posterior in a panoramic image?

Answer 26

Anterior

Question 27

T/F: Horizontal measurements made on pano radiographs are reliable

Answer 27

False

Question 28

▪ Every anatomical structure positioned between the

center of rotation and the receptor.

Answer 28

Real images

Question 29

▪Created by objects located between the x-raysource and the center of rotation.
▪Appear on the opposite side, at a higher level,blurred and magnified.
▪Anatomical structures that cast a ghost imageinclude:
▪ Inferior border of the mandible, angle, ramus,hyoid, cervical spin, jewelry (earrings, hairpinsand neckless) and palate

Answer 29

Ghost images

Question 30

▪ Appears on the opposite side
▪ Positioned higher than real structure
▪ More blurred than the real structure
▪ Vertical component is highly magnified

Answer 30

Ghost images

Question 31

▪ Objects that lie posterior to the center of rotation and
that are intercepted twice by the x-ray beam
▪ Includes the hyoid bone, epiglottis and cervical spine,
all of which cast images on both the right and left side of
the image.
▪ All double images are also real
-In between both centers of rotation

Answer 31

Double images

Question 32

What are the 3 structures that are captured as real, ghost, and double images?

Answer 32

Hyoid
Epiglottis
Cervical spine