RAD02 - Lecture 2 - Bitewings

Question 1

What are the clinical indications for bitewings? (4)

Answer 1

Detect caries

Monitor progression of caries

Assess existing restorations

Assess periodontal status

Question 2

What are the 2 main bitewing projections?

Answer 2

Horizontal bitewings

Vertical bitewings

Question 3

Identify the bitewing projection

Answer 3

Vertical bite wings - need 2 films (one for premolars:mesial 1st molar, other for other molars)

Question 4

Identify the bitewing projection

Answer 4

Horiztonal bitewings - film parallel to arch (including mesial edge of 1st premolar -> distal edge of second molar)

Question 5

What is the angulation of the tube head for bitewings?

Answer 5

5-8^o downwards

Question 6

What are the advantages of using image receptor holders?

Answer 6

Simple to use

Film packet (phosphor plate) or solid state (digital) sensoris held firmly in position and cannot be displaced

Horiztonal and vertical position of the tubehead determined by the beam aiming device

Avoids coning off or cone cutting

Sterilisable or disposable

Question 7

What are the disadvantages of using image holders? (4)

Answer 7

Images are not 100% reproducible (positioning is operator-dependant) - not ideal for monitoring progression of caries

Can be uncomfortable

Expensive

Difficult to use on children

Question 8

What type of “holder” is being used in the image?

Answer 8

Bitewing Tab (used traditionally for horiztonal adult bitewings)

Question 9

How does the tab need to be adjusted if your doing vertical bitewings?

Answer 9

Attach tab to phophor plate with long axis vertical

Question 10

What are the advantages of using Tabs (wing)? (4)

Answer 10

Simple

Cheap

Disposable (no need for extra infection control measures)

Can be used for children

Question 11

What are the disadvantages of tabs (wings)?

Answer 11

Assessing horizontal and vertical angulations is operator-dependent (arbitary)

Overlapping

Coning off and cone cutting (of anterior part of image is common)

Tongue can easily displace the film packet/phosphor plate (not held firmly)

Question 12

What size phosphor plates would you use for children? (4)

Answer 12

Age 12 (erupted 2nd molars) -> size 2 with holder

Age 10-11 (mixed dentition) -> size 2 or 1 with holder/tab

Age 7-10 -> size 1 or 0 with holder/tab

Age 4-7 -> size 0 with tabs

Question 13

What teeth needs to be shown on a childs horizontal bitewing?

Answer 13

Deciduous molars and 1st molar if erupted

Question 14

What size film packet (not used in guy’s) should be used for children? (1)

Answer 14

Size 0

Question 15

What is the purpose of a vertical bitewing on children?

Answer 15

Assess developing pre-molars

See apices of deciduous molars

Question 16

What is the criteria for an ideal quality bitewing? (7)

Answer 16

Occlusal plane in the middle -> image (parallel to top and bottom of image receptor)

Include distal aspect of the canines -> mesial aspect of third molars

Crowns, necks and coronal third (1/3rd root) of all teeth clearly defined

Periodontal bone levels clearly defined

No vertical geometrical distoration

All contact areas clearly shown with no overlapping (of crowns)

Contrast and density -> differentiate between enamel, dentine, pulp and EDJ clearly visualised for caries diagnosis