Week 5 Day2 Ch 22 Exposure & Technique Err.

Question 1

UNEXPOSED FILM

Answer 1

• Film appears clear
• Film was not exposed
• To ensure proper exposure of the film, make sure that the x-ray unit is on and listen for the audible exposure signal
•X-ray machine was not on, there was an electrical failure, malfunction of the machine

Question 2

FILM EXPOSED TO LIGHT

Answer 2

• Film appears black
• Film was accidentally exposed to white light
• Check the darkroom for possible light leaks
• Before unwrapping the film in the darkroom, turn off all lights (except safelight)
• Do not unwrap where there is white light

Question 3

OVEREXPOSED FILM

Answer 3

• The film appears dark
• The film was overexposed ie: excessive exposure time, kVp or mA
“ Adjust the control panel settings when necessary eg: child, elderly
- Check exposure time and settings, reduce as needed

Question 4

UNDEREXPOSED FILM

Answer 4

• The film appears light
• The film was underexposed ie:
insufficient exposure time, kVp, or mA
• Check settings and increase as needed

Question 5

CORRECT FILM PLACEMENT

Answer 5

• Each PA film must be positioned a certain way exhibiting specific teeth and related anatomic structures
“The edge of the PA film must be placed parallel to the incisal or occlusal surfaces of the teeth and extend 1/8 inch beyond the incisal or occlusal surfaces

Question 6

INCORRECT FILM
PLACEMENT

Answer 6

” Failure to see the apices on a PA radiograph resulting in an excessive margin of film edge (black band)
C: Inadequate Apical
Coverage
“ Ensure that no more than
1/8 inch of the film edge extends beyond the incisal-occlusal surfaces of the teeth

Question 7

INCORRECT FILM
PLACEMENT

Answer 7

• The occlusal plane appears tipped or tilted on a radiograph because the edge of the film was not placed parallel to the incisal-occlusal surfaces of the teeth
H: Line of Occlusion
• If the client is not instructed to hold the film firmly against the tooth, a corner of the film may drop or slip
“ This occurs in the digital method (holding film with finger)
• This can also occur if the client fails to close his mouth

Question 8

INCORRECT HORIZONTAL
ANGULATION

Answer 8

” The processed film appears to have overlapping of the contact
areas
D: Overlapping
• The central ray was not directed through the interproximal spaces a The use of Rinn XCP instruments minimize errors in HA

Question 9

INCORRECT HORIZONTAL
ANGULATION

Answer 9

Overlapped contacts appear on a bite-wing exposure
Overlapped contacts prevent examination of interproximal areas
When the contacts are opened, a thin radiolucent line is evident between the proximal surfaces of the teeth

Question 10

INCORRECT VERTICAL
ANGULATION (FORESHORTENING)

Answer 10

•Caused from excessive vertical angulation ie: PID is too steep
J: Foreshortening
“ The teeth appear short with blunted roots
• The radiographic image appears shorter than the actual tooth

Question 11

INCORRECT VERTICAL
ANGULATION (ELONGATION)

Answer 11

•Caused from insufficient vertical angulation (too flat)
I: Elongation
• The teeth appear long and distorted
•The radiographic image appears longer than the actual tooth

Question 12

INCORRECT VERTICAL
ANGULATION

Answer 12

• Image appears distorted on a bite-wing exposure
• Results when a negative vertical angulation is used
• Utilize a +10 degree vertical angulation when taking bite-wing exposures
• PID must be positioned downwards
• This compensates for the slight tilt of the maxillary teeth and the slight lingual bend of the upper half of the film caused by the hard palate

Question 13

CONE-CUT

Answer 13

• A clear (unexposed) crescent appears on the film
E: Cone Cut
• The PID was not properly aligned with the film holder and the x-ray beam did not expose the entire film
• Always ensure that the central ray is centered over the film and that the entire film is covered by the diameter of the PID

Question 14

FILM PLACEMENT
(PREMOLAR BITE-WING)

Answer 14

” Must be positioned so that the resulting film shows both the maxillary and mandibular premolars and the distal contact areas of both canines
Ensure that the film is positioned so that the front edge of the film is aligned with the middle (mesial) of the mandibular canine
• A: Incorrect Film Placement

Question 15

FILM PLACEMENT
(MOLAR BITE-WING)

Answer 15

• Must be positioned so that the resulting film shows both the maxillary and mandibular molars (1st, 2nd, 3rd)
“ Ensure that the film is positioned so that the front edge of the film is aligned with the middle (mesial) of the mandibular second premolar

Question 16

FILM BENDING

Answer 16

• Image appears stretched and distorted
  • Avoid bending the film excessively either from heavy finger pressure or the curvature of the palate
  “ If the client’s finger pressure is excessive, instruct the client to stabilize the film gently
  • If the film is bent due to the curvature of the hard palate, use cotton rolls
  • Film holders are helpful in preventing film bending

Question 17

FILM CREASING

Answer 17

• A thin radiolucent line appears on a processed film
• The film was creased causing the film emulsion to crack resulting in a thin radiolucent line
• Ensure that the corners of the film are gently softened using your palm prior to placing the film in the client’s oral cavity
• Do not bend excessively, gently soften corners of the film before positioning intra-orally
N: Other

Question 18

PHALANGIOMA

Answer 18

• PHALANX / PHALANGES
• Any bone of a finger
• The client’s finger appears on the film
“ The client’s finger was incorrectly positioned in front of the film instead of behind the film
• Occurs when the finger-holding method is used in the bisecting technique

Question 19

DOUBLE EXPOSURE

Question 20

MOVEMENT

Answer 20

Blurred images appear on the film “PENUMBRA”
- The client moved during exposure of the film
Ensure that the client’s head is stabilized before exposing the radiograph
- Always instruct your client to sit still (remain motionless)

Question 21

REVERSED FILM

Answer 21

” Light images with a herringbone pattern appear on the film (“tire-track” or “waffle image”)
•The herringbone pattern on the radiograph is representative of the actual pattern embossed on the lead foil
• The film was placed in the mouth backwards and then exposed
• Ensure that the white smooth or pebbly side of the film packet is facing tube head (radiographer)
K: Reversed Plate

Question 22

REVERSED
PHOSPHOROUS
PLATE

Answer 22

• The radiopaque circle on the radiograph is representative of the magnetic circle on the phosphorous plate
“ The film was placed in the mouth backwards and then exposed
• Also ensure that the plate is packaged correctly otherwise the radiographer is unable to determine the correct intraoral placement of the plate
K: Reversed Plate

Question 23

STATIC ELECTRICITY

Answer 23

• Results from opening the film packet too quickly
• Ensure that the film is removed slowly from the film packet

Question 24

POOR RESOLUTION (POOR CONTRAST)

Answer 24

• Check kVp on control panel (usually preset by supplier)
  • To correct it, call dental supplier to readjust setting
  • If using digital
  radiography, can adjust contrast to enhance
  image
  F: Exposure Error

Question 25

INCORRECT ORIENTATION OF THE FILM OR PLATE

Answer 25

• Ensure that film or plate is positioned vertically for an anterior periapical exposure and positioned horizontally for a horizontal periapical exposure
• Tip: Follow the orientation of the bite block
A: Incorrect Film Placement

Question 26

SCRATCHED FILM

Answer 26

• A scratched film from nails or a sharp object = To correct this, remove the film by the film edge and keep the film away from all sharp objects
• Beware: phosphorous plates used in digital radiography are fragile, handle with care and ensure that they are scanned carefully