Intraoral Radiography Techniques

Question 1

What are 3 principles of radiation protection

Answer 1

JustificTion
Optimisation - x ray tube is more efficient and shorter exposure times. Rectangular Collimator is used
Limitation

Question 2

How do you achieve the best quality images

Answer 2

• keep the film and object as close together as possible and parallel to the object
• film beyond the apices of the tooth
• the x eat sour se to the object distance as great as possible
• x ray beam perpendicular tot he object and the film

Question 3

What are the 3 categories of intractable radiography

Answer 3

Bitweings
Occlusal
Periapical

Question 4

What do bitewings show and what are their characteristics

Answer 4

Bitweings show crowns of premolars and molars of both jaws
- no/ minimal overlap of enamel (up to half thickness is acceptable)
- see from contact point between canine and first pre molar to the most distal contact point
- horizontal will show superfiakc bone levels of bone loss is more than 6mm

Question 5

What are indications tk use Bitweings

Answer 5

Detecting approximately,occlusal m, or recurrent caries
Assessing depth of caries or monitoring their progression
Checking for overhangs or calculus deposit
Assessing superficial bone levels

Question 6

What is the technique for bitewings (horizontal)

Answer 6

Use a logn axis of horizontal film and ask patient to bit block in the middle of the film
Hold it as close as possible and parallel to the teeth
Beam projects at right angles to the film horizontally and vertically

Question 7

What is technique for vertical bitewings

Answer 7

The long axis of the film is vertical
Each film covers fewer teeth but shows more alveolar bone
Two each side to cover posterior teeth

Question 8

What are the characteristics using film holders

Answer 8

Simple, film not displaces by tongue and then the beam always at right angles to the film

Less chance of cone cutting and reproducible techniques

Disadvantage is more expensive initially and may be uncomfortable

Question 9

What is an alternative method to using film holders

Answer 9

Using adhesive tab technique
Cheap simple and good for small children
Not reproducible
Operator dependant

Question 10

What do periapical technique show?

Answer 10

Include all the tooth and periapical tissues approximately 3mm beyond the apex

Question 11

What are the indications to use a periapical techqniey

Answer 11

Apical pathology (osteitis,cysts,root resorption
Periodontal disease or endodontics
Root morphology before extraction or impacted teeth
Implant assessment or trauma

Question 12

What is the technique for periapical technique

Answer 12

Film holder and beam aiming ring
- holds film parallel to the tooth
Aids correct alignment of beam with image detector

Question 13

What film size and ring so anterior periapical a use

Answer 13

Film size 0
Blue bite ring

Question 14

What film size and ring does posterior periapical use

Answer 14

Film size 2
Yellow bite block

Question 15

What is places between bite block and opposing teeth

Answer 15

Cotton wool roll is places between the bite block and opposing teeth

Question 16

What are th eadvanatheous of the paralleling technique

Answer 16

Confirms 3.36 of guidance
Reproducible radiographs
- geometric accuracy
-less foreshadowing
-less likelihood of distortion due to film bending
Less superimposition if zygomatic over maxillary molars
Localising ring minimises cone cutting
So fewer repeats and therefore lower dose

Question 17

What are the disadvantages of paralleling technique

Answer 17

Expedience
Holders need to be sterilised
Careful and accurate placement required
Some patients find it uncomfortable
Longer to perform a full mouth survey as smaller films uses anteriorly

Bisecting angle technique could be sued

Question 18

What is occlusal technique

Answer 18

Like bisecting angle periapical

Use larger film size and circular collimator
Film is held between teeth and is parallle to the occlusal plane
Maxillary: use alar tragus line
Mandibular: use corner of mouth to tragus

Question 19

What are the indications of using occlusal x ray teycnique

Answer 19

Pathology not fully covered by periapical
Assess impacted teeth such as maxillary canines
Used in localisation in conjunction with other films
Trauma and bony expansion of mandible
Submandibular duct stones

Question 20

Why is a maxillary true radiograph useless

Answer 20

Inclination of maxillary incisors does not allow a cross sectional view
Bones of face and skull are superimposed over it

Question 21

What can be used to show the anterior teeth

Answer 21

Maxillary oblique occlusal