Principles of Pano

Question 1

4 advantages of pano?

Answer 1

1. broad coverage 2. low dose 3. rapid 4. can be used with trismus

Question 2

3 disadvantages of pano?

Answer 2

1. positioning critical 2. inherent magnification/poor res 3. 👻 image and overlapped molars

Question 3

Pano good for evaluating (6)

Answer 3

1. trauma 2. third molars 3. large disease/lesions 4. retained root tip 5. dev abnormalities 6. mixed dentition

Question 4

Pano uses wide or narrow beam?

Answer 4

narrow

Question 5

What is a focal trough?

Answer 5

3D curved zone where structures are well-focused

Question 6

Section thickness vs tube travel relationship?

Answer 6

inversely proportional

Question 7

Real image formed when object located where?

Answer 7

between center of rotation and film

Question 8

👻 shadows formed when object located where?

Answer 8

between source and rotation center

Question 9

👻 shadows position different? vertical component?

Answer 9

higher, vertical is magnified

Question 10

Moving towards rotation center, things get more…

Answer 10

magnified?

Question 11

Image is squashed horizontally, can see spine, means…

Answer 11

pt too far forward

Question 12

Image stretched horizontally, can see whole ramus, means…

Answer 12

pt too far back

Question 13

Mandible flat, teeth sloped downwards/sad face, means…

Answer 13

pt jaw upwards

Question 14

“too much smiling/concavity” means..

Answer 14

pt jaw downwards

Question 15

When pt slouches, what happens to image?

Answer 15

cervical vertebrae get into focal trough, see shadow of spine in middle of image

Question 16

Problem?

Answer 16

Too far front; anterior teeth extremely thin

Question 17

Problem?

Answer 17

Chin up, too far back; condyles cut off of sensor b/c too close to sensor

Question 18

Problem?

Answer 18

Chin too low, roots are tiny which means roots are lingually inclined

Question 19

Problem?

Answer 19

Dark bands - tube got stuck 4 times

Question 20

Problem?

Answer 20

pt turned towards right

Class II pt

Patient moved

Question 21

Problem?

Answer 21

Chin down

Pt looking left

lead apron high on neck, projects apron on image (thyroid collar contraindicated for pano)

apron on back needs to be low neckline

Question 22

Problem?

Answer 22

want tongue to sit against palate, here too much air b/c pt did not put tongue against palate; allows you to see apices of max teeth.

Question 23

Problem?

Answer 23

Film exposed to light, fogging

Question 24

Problem

Answer 24

static

Question 25

Problem

Answer 25

Ghost shadows of earrings