Week 3 Lecture Objectives

Question 1

In what position would you need to use a type 0 film

Answer 1

with children it is 22X 35 MM

Question 2

In what position would you need to use a type 1 film and what is its size?

Answer 2

with adult anterior and it is 25x 40 MM

Question 3

In what position would you need to use a type 2 film and what is its size?

Answer 3

this is the standard for adults Pariapicals and Bitewings it is size 30.5 and 40.5 MM

Question 4

In what position would you need to use a type 4 film and what is its size?

Answer 4

occlusal film used for floor and roof o mouth to find extra teeth. Its size is 57 x 76 MM

Question 5

What is a bisecting technique?

Answer 5

Film/sensor placed on an angle against the incisal edge of the teeth​.

Question 6

What is a paralleling technique?

Answer 6

Film/sensor placed parallel to long axis of tooth​

Question 7

What closed contact error requires a retake?

Answer 7

If your overlap crosses the DEJ (dentinoenamel junction) and it can not be seen on any other film, it requires a retake​

Question 8

What is foreshortening and how do you fix it?

Answer 8

Vertical angulation error and fix the over angulated beam

Question 9

What is elongation and how do you fix it?

Answer 9

vertical angulation error and fix the over angulated beam

Question 10

How do you determine a vertical angulation error?

Answer 10

Look for extreme cusp separation​
Check the same tooth on the opposite side of the mouth and compare size​
Maxillary molar projection- lingual root will appear larger and buccal roots will appear smaller​
Mandibular anterior projection-will often see the border of the mandible in the film

Question 11

How do you determine a placement error?

Answer 11

Missing crown areas​, but only retake if half or more than half of the crown area is missing​
Missing apex​
Always needs a retake unless you can see on a different film​
Not far enough forward​ or back

Question 12

What is cone-cutting & how do you fix it?

Answer 12

Where can only see white border. Fix BID placement with XCP ring.

Question 13

What are the advantages for paralleling?

Answer 13

Minimal distortion​
Tooth and film easy to see and direct x-ray beam appropriately​
Many film holders (XCPs)​

Question 14

What are the disadvantages of paralleling?

Answer 14

Parallel film/sensor placement difficult in some patients ​
small mouth, low palatal vault, presence of tori, gag reflex​
May cause patient discomfort​

Question 15

What are the advantages of bisecting?

Answer 15

Film/sensor placement easier in some patients​

small mouth, low palatal vault, presence of tori, gag reflex

Question 16

What are the disadvantages of bisecting?

Answer 16

More dimensional distortion​

Estimating location of imaginary bisector may be difficult​

Question 17

What is the key contact for Central Incisor Region?

Answer 17

mesial and distal of central incisors​

Question 18

What is the key contact for Canine Region?

Answer 18

open contact between canine and lateral incisor ​

Question 19

What is the key contact for Premolar Region?

Answer 19

open contact between first and second premolar​

Question 20

What is the key contact for Molar Region?

Answer 20

open contact between first and second molar​

Question 21

What is the ultimate goal of an FMX?

Answer 21

All contacts open at least once in series​
All apices visible at least once in series​
2 mm surrounding tooth area at least once​
All incisal edges visible*

Question 22

What should you see in a properly mounting maxillary area?

Answer 22

Maxillary sinus- arrow pointing to line​

Anterior teeth larger than mandibular

Question 23

What should you see in a properly mounting mandible area?

Answer 23

Two roots​
Curve of Spee​
External oblique ridge​
Anterior smaller than maxillary