RAD02 - Lecture 6 - Occlusal

Question 1

Define occlusal radiography (1)

Answer 1

Intra-oral technique where the image receptor (i.e. film packet or phosphor plate) is placed on the occlusal plane

Question 2

Can you use solid state sensors for occlusal radiographs?

Answer 2

No

Question 3

What are the 5 different types of occlusal radiographs?

Answer 3

Maxillary

Upper standard

Upper oblique

Mandibular

Lower 45^o

Lower 90^o

Lower oblique (just same as upper oblique but for lowers)

Question 4

What are the 2 image receptors that can be used for occlusals?

Answer 4

Phosphor plate

Film packet (size 4)

Question 5

Identify the type of occlusal radiograph - what is it showing?

Answer 5

Upper Standard Occlusal -> anterior maxilla (upper anteriors)

Question 6

What are the clinical indications for Upper Standard Occlusals? (5)

Answer 6

Evalute size/extent of lesions (i.e. cysts, tumours) -> anterior maxilla

Peri-apical of anterior maxilla teeth (for patients who cant tolerate PAs)

Orthodontics -> detects presence of unerupted canines, supernumaries, odontomes

As a mid-line view when locating unerupted canines, supernumeraries, odontomes

Dento-aveolar trauma -> anterior maxilla

Question 7

Describe the technique for Upper Standard Occlusal (5)

Answer 7

1) Seat patent with head supported and occlusal plane horizontal

2) Use protective thryoid shield

3) Insert image receptor flat into the mouth (so its on the occlusal surface of the lower teeth)

4) Tell patient to bite genetly together

5) Position the X-ray tubehead above the patient at the midline

6) Angulate the tubehead at a 65-70^o downwards through the bridge of the nose -> image receptor

Question 8

Identify the 8 structures that should be shown in an upper standard occusal (anterior maxilla)

Answer 8

Question 9

How is the technique for Upper Standard Occlusal modified for children? (2)

Answer 9

Use small size 2 phosphor plate or film

Angulation of X-ray tube-head -> 50^o

Question 10

Describe the quality criteria for Standard Upper Occlusals (7)

Answer 10

Apices of upper incisiors clearly defined

Unerupted canines (if present) - crows and apices

First and second molars should be included

Right and left should be comparable

Minimal elongation/foreshortening***

No geometrical distortion (from incorrect angulation or film bending)***

Contrast and density should allow you to differentiate -> enamel, dentine, pulp***

*** -> same for all occlusal radiographs (except contrast/density for 1)

Question 11

Identify the type of occlusal radiography

Answer 11

Upper Oblique Occlusal - posterior maxilla (upper posteriors)

Question 12

Describe the technique for Upper Oblique Occlusal (6)

Answer 12

1) Seat patent with head supported and occlusal plane horizontal

2) Use protective thryoid shield

3) Insert image receptor flat into the mouth (with long axis antero-posteriorly to the side of the mouth under investigation)

4) Tell patient to bite genetly together

5) Position the X-ray tubehead to the side of the patients face

6) Angulate the tubehead at a 65-70^o downwards through the cheek -> image receptor

Question 13

Describe the quality criteria for Upper Oblique Occlusals? (6)

Answer 13

Apices of upper posterior teeth being investigated clearly defined

All posterior teeth on one side should be included

Antral floor should be shown

• Minimal foreshortening/elongation*
• No additional geometrical distoration (from incorrect angulation/film bending)*
• Contrast and density should allow differentiation -> enamel, dentine, pulp*

Question 14

Identify the 5 structures that should be shown in an upper oblique occusal (posterior maxilla)

Answer 14

Question 15

Identify the type of occlusal radiograph

Answer 15

Lower 45^o Occlusal

Question 16

What are the clinical indications for Lower 45^o Occlusals? (4)

Answer 16

Dento-alveolar trauma -> in conjunction with PAs

Evalulation of the size and extent of lesions -> anterior mandible

Peri-apical -> anterior mandible teeth (for people who cant tolerate PAs)

Vertical displacement of fractures -> anterior mandible

Question 17

Describe the technique for Lower 45^o Occlusals (5)

Answer 17

1) Seat patent with head supported and occlusal plane horizontal

2) Insert image receptor centrally into the mouth (with long axis antero-posterioly or crossways)

3) Tell patient to bite genetly together

4) Position the X-ray tubehead at the midline

5) Angulate the tubehead at a 45^o upward through the chin -> image receptor

Question 18

Describe the quality criteria for Lower 45^o Occlusals (5)

Answer 18

Apices of lower incisor teeth should be clearly defined

Lower border of the mandible should be shown

• Minimal foreshortening/elongation*
• No additional geometrical distoration (from incorrect angulation/film bending)*
• Contrast and density should allow differentiation -> enamel, dentine, pulp*

Question 19

Identify the 3 structures that should be shown in a lower 45^o occlusal (anterior mandible)

Answer 19

Question 20

Identify the type of occlusal radiograph

Answer 20

Lower 90^o Occlusal

Question 21

What are the clinical indications for Lower 90^o Occlusals? (6)

Answer 21

Detection of calculi in the submandibular duct

Bucco-lingual expansion of lesions (affecting mandible)

Bucco-lingual position of unerupted teeth (including wisdom)

Mandibular tori

Horiztonal displacement of fractures

Implants (assessment)

Question 22

Describe the technique for Lower 90^o Occlusals

Answer 22

1) Insert image receptor centrally into the mouth (with long axis antero-posterioly or crossways)

2) Tell patient to bite genetly together

3) Tip patients head backwards (as far as comfortable)

4) Position the X-ray tubehead below the body of the mandible (in the side of interest)

5) Angulate the tubehead at a 90^o upward through the chin/neck -> image receptor

Question 23

Identify the 4 structures that should be shown in Lower 90^o Occlusals

Answer 23

Question 24

Describe the quality criteria of lower 90^o occlusals (4)

Answer 24

First molar teeth should be included

Body of the mandible on each side should be equidistant (equal distance) from the midline (appears symmetrical)

Contrast and denisty will depend on the cinlical indication - i.e. demonstrate salivary calculi -> soft tissue exposure should be used

Question 25

Identify which type of occlusal radiograph is each of these

Answer 25

Left = Lower 90 -> space for tongue

Right = Lower 45 -> apices of incisiors

Question 26

Identify the type of occlusal radiograph

Answer 26

Left = Upper Oblique -> apices of upper molars

Right = Upper standard -> apices of upper incisiors