Transcript EXPOSURE AND TECHNIQUE ERRORS

EXPOSURE AND TECHNIQUE
ERRORS
DA 105
Dental Radiography
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Questions
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What film exposure and technique errors
may be observed on dental radiographs?
What horizontal and vertical angulation
errors may be observed on dental
radiographs?
What is the proper film placement for bitewing radiographs?
Dental Radiography
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Exposure and Technique Errors
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Film exposure errors
Technique errors (periapical films)
Technique errors (bite-wing films)
Miscellaneous technique errors
Exposure and Technique
Errors
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Purpose
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To describe film exposure problems and
periapical, bite-wing, and miscellaneous
technique errors
Film Exposure Errors
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Exposure Problems
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Unexposed film
Film exposed to light
Time and Exposure Factor Problems
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Overexposed film
Underexposed film
Unexposed Film
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Appearance
 The film appears clear
Cause
 Failure to turn on the x-ray machine
 Electrical failure
 Malfunction of the x-ray machine
Correction
 Make certain the x-ray machine is turned on and
listen for the audible exposure signal
An unexposed film appears
clear
Film Exposed to Light
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Appearance
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Cause
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The film appears black
The film was exposed to white light
Correction
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Do not unwrap in a room with white light
Check the darkroom for light leaks
Turn off all lights in the darkroom except
the safelight
A film exposed to light appears black
Overexposed Film
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Appearance
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Cause
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Film appears dark
Excessive exposure time, kilovoltage,
milliamperage
Correction
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Check settings and reduce as needed
before exposing film
An overexposed film appears dark
Underexposed Film
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Appearance
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Cause
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The film appears light
The film was underexposed
Correction
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Check the exposure time, kilovoltage, and
milliamperage settings on the x-ray
machine before exposing the film
An underexposed film appears light
Technique Errors (Periapical
Films)
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Film Placement Problems
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Correct film placement
Incorrect film placement
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Angulation Problems
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Absence of apical structures
Dropped film corner
Incorrect horizontal angulation
Incorrect vertical angulation
PID Alignment Problems
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Cone-cut with Film Holder
Cone-cut without Film Holder
Correct Film Placement
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Each periapical film must be positioned
in a certain way to show specific teeth
and related anatomic structures
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The edge of the periapical film must be
placed parallel to the incisal or occlusal
surfaces of the teeth and extend 1/8th inch
beyond the incisal or occlusal surfaces
Correct periapical film placement demonstrates
the entire tooth, including the apex and
surrounding structures
Absence of Apical Structures
Haring (p. 276) (Fig. 20-6)
Appearance
 No apices appear on the film
Cause
 The film was not positioned in the patient’s mouth
to cover the apical regions of the teeth
Correction
th inch of the film
 Make certain no more than 1/8
edge extends beyond the incisal-occlusal surfaces
of the teeth
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Improper film placement; no
apices appear on this film
Dropped Film Corner
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Appearance
 The occlusal plane appears tipped or tilted
Cause
 The edge of the film was not placed parallel to the
incisal-occlusal surfaces of the teeth
Correction
 Make certain the edge of the film is placed parallel
to the incisal-occlusal surfaces of the teeth
Improper film placement; a dropped film corner is
seen when the edge of the film is not placed parallel to
the incisal or occlusal surfaces of the teeth
Incorrect Horizontal
Angulation
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Appearance
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Cause
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Overlapped contacts
The central ray was not directed through
interproximal spaces
Correction
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Direct the x-ray beam through interproximal
regions
Incorrect horizontal angulation
results in overlapped contact areas
Incorrect Vertical Angulation
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Foreshortened images
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Appearance
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Cause
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Short teeth with blunted roots
Excessive vertical angulation
Correction
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Do not use excessive vertical angulation with
the bisecting technique
If the vertical angulation is too steep, the image
of the tooth on the film is shorter than the
actual tooth; the images are foreshortened
Incorrect Vertical Angulation
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Elongated images
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Appearance
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Cause
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Long, distorted teeth
The vertical angulation was insufficient
Correction
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Use adequate vertical angulation with the
bisecting technique
If the vertical angulation is too flat, the image of the
tooth on the film is longer than the actual tooth; the
images are elongated
PID Alignment Problems
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Cone-cut with film holder
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Appearance
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Cause
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A clear area appears on the film
The PID was not properly aligned with the
periapical film holder
Correction
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Make certain the x-ray beam is centered over
the film
A cone-cut is seen when the PID is not
properly aligned with the periapical filmholding device
PID Alignment Problems
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Cone-cut without film holder
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Appearance
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Cause
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A clear area appears on the film
The PID was not directed at the center of the
film
Correction
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Make certain the x-ray beam is centered over
the film
A cone-cut appears as a curved
unexposed (clear) area on a radiograph
Technique Errors (Bite-Wing
Films)
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Film Placement Problems
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Angulation Problems
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Correct film placement
Incorrect film placement
Incorrect horizontal angulation
Incorrect vertical angulation
PID Alignment Problems
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Cone-cut with film holder
Cone-cut without film holder
Correct Film Placement
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Premolar bite-wing
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The resulting film shows both the maxillary
and mandibular premolars and distal
contact areas of both canines
Molar bite-wing
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The resulting film shows both the maxillary
and mandibular molars
Correct film placement for the premolar
bite-wing
Correct film placement for the molar
bite-wing
Incorrect Film Placement
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Premolar bite-wing
 Appearance
 Distal surfaces of the canines are not visible on the film
 Cause
 The bite-wing film was positioned too far posteriorly in
the mouth
 Correction
 Make certain the anterior edge of the bite-wing film is
positioned at the midline of the mandibular canine
Incorrect film placement for the
premolar bite-wing
Incorrect Film Placement
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Molar bite-wing
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Appearance
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Cause
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Third molar regions are not visible on film
The bite-wing film was positioned too far
anteriorly in the mouth
Correction
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Make certain the anterior edge of the bite-wing
film is positioned at the midline of the
mandibular second premolar
Incorrect film placement for the
molar bite-wing
Incorrect Horizontal
Angulation
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Appearance
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Cause
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Overlapped contacts on the film
The central ray was not directed through
the interproximal spaces
Correction
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Direct the x-ray beam through the
interproximal spaces
Overlapped interproximal contacts result
from incorrect horizontal angulation
Incorrect Vertical Angulation
Appearance
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Cause
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Images appear distorted on the film
The vertical angulation was incorrect
Correction
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Always use a +10-degree vertical
angulation with the bite-wing technique
Incorrect vertical angulation causes
the images to appear distorted
Cone-Cut With Film Holder
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Appearance
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Cause
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A clear area appears on the film
The PID was not properly aligned with
the film holder
Correction
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Make certain the PID and the aiming
ring are aligned
A, A cone-cut is seen when the PID is not properly aligned with the
bite-wing film-holding device. B, A cone-cut can also be produced
with rectangular collimation; the PID is not properly aligned with
the bite-wing film-holding device
Cone-Cut Without Film Holder
Appearance
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Cause
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A clear area appears on the film
The PID was not directed at the center of
the film
Correction
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Make certain the x-ray beam is centered
over the film
A cone-cut appears as a curved
unexposed (clear) area on a
radiograph
Miscellaneous Technique
Errors
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Film Bending
Film Creasing
Phalangioma
Double Exposure
Movement
Reversed Film
Film Bending
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Appearance
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Cause
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Images appear stretched and distorted
The film was bent excessively
Correction
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Check film placement before exposure
A bent film appears distorted
Film Creasing
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Appearance
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Cause
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A thin radiolucent line appears on the film
The film was creased
Correction
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Do not bend or crease the film excessively
A film crease appears as a thin
radiolucent line
Phalangioma
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Appearance
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The patient’s finger appears on the film
Cause
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Haring (p. 282) (Fig. 20-23)
The patient’s finger was positioned in front
of the film
Correction
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Make certain the patient’s finger is placed
behind the film
This film demonstrates a phalangioma;
the bones of a patients finger appear on
the film
Double Exposure
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Appearance
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Cause
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A double image appears on the film
The film was exposed twice in the patient’s
mouth
Correction
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Always separate exposed and unexposed
films
This film demonstrates a double
exposure
Movement
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Cause
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Appearance
Blurred images appear on the film
The patient moved during exposure of the
film
Correction
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Instruct the patient to remain still while the
film is being exposed
Movement results in a blurred image
Reversed Film
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Appearance
 Light images with a herringbone pattern appear
on the film
Cause
 The film was placed backward in the mouth and
then exposed
Correction
 Always place the white side of the film adjacent to
the teeth
A reversed film appears light with a herringbone
(or tire-track) pattern. The tire-track pattern is
seen on the lead-foil backing within the film
packet
EXPOSURE AND TECHNIQUE ERRORS
DIAGNOSTIC DENTAL RADIOGRAPH:
1.FILM EXPOSURE ERRORS:
EXPOSURE
PROBLEMS
a) Unexposed
film
b) Film exposed to
light
TIME AND
EXPOSURE FACTOR
PROBLEMS
a) Overexposed film
b) Underexposed
film
APPEARANCE
CAUSE
CORRECTION
TECHNIQUE ERRORS(PERIAPICAL
FILMS)
1.
2.
3.
FILM PLACEMENT PROBLEMS
ANGULATION PROBLEMS
PID ALIGNMENT PROBLEMS
FILM PLACEMENT PROBLEMS
ERROR
CORRECT
FILM
PLACEMENT
INCORRECT FILM
PLACEMENT
a) ABSENCE OF
APICAL
STRUCTURES
b) DROPPED
FILM CORNER
APPEARANCE
CAUSE
CORRECTION
ANGULATION PROBLEMS
ERROR
INCORRECT
HORIZONTAL
ANGULATION
INCORRECT
VERTICAL
ANGULATION
a)
FORESHORTENED
IMAGE
b) ELONGATED
IMAGE
APPEARANCE
CAUSE
CORRECTION
PID ALIGNMENT PROBLEMS
ERROR
CONE-CUT
WITH FILM
HOLDER
CONE-CUT
WITHOUT
FILM HOLDER
APPEARANCE
CAUSE
CORRECTION
TECHNIQUE ERRORS(BITE-WING FILMS)
1.
2.
3.
FILM PLACEMENT PROBLEMS
ANGULATION PROBLEMS
PID ALIGNMENT PROBLEMS
FILM PLACEMENT PROBLEMS
ERROR
CORRECT FILM
PLACEMENT
1)PREMOLAR BITEWING
2)MOLAR BITEWING
INCORRECT FILM
PLACEMENT
1)PREMOLAR BITEWING
2)MOLAR BITEWING
ANGULATION PROBLEMS
ERROR
INCORRECT
HORIZONTAL
ANGULATION
INCORRECT
VERTICAL
ANGULATION
APPEARANCE
CAUSE
CORRECTION
PID ALIGNMENT PROBLEMS
ERROR
CONE-CUT
WITH FILM
HOLDER
CONE-CUT
WITHOUT
FILM HOLDER
APPEARANCE
CAUSE
CORRECTION
MISCELLANEOUS TECHNIQUE ERRORS
ERROR
1.FILM
BENDING
2.FILM
CREASING
3.PHALANGIO
MA
4.DOUBLE
EXPOSURE
5.MOVEMENT
6.REVERSED
FILM
APPEARANCE
CAUSE
CORRECTION