Film Faults OPG Flashcards
What is the film fault?
What is the film fault?
Head turned to the left. The ramus is wider on the right side.
Head turned to the right, moving the teeth closer to the film on that side. The teeth on
the left side, being farther from the film, will be magnified more and appear larger.
The head is turned to one side, causing an asymmetry of the condyles, and wider teeth
and ramus on one side than the other
The head is tilted to one side, causing one condyle to appear higher than the other and
the inferior border of the mandible is slanting.
Here’s a mnemonic to remember the key points of “too anterior OPG fault”:
**“A Front Blur Squeeze”
**
A: Anterior teeth positioned too forward.
Front: Teeth closer to the front of the film.
Blur: Images of the teeth are blurred because they’re outside the focal trough.
Squeeze: Teeth appear squeezed (narrowed) due to less magnification.
The central incisors are in front of the bite groove, causing them to appear thin and
fuzzy. The cervical spine is in the focal zone, causing it to be superimposed on the
mandible.
Here’s a mnemonic to remember the key points of “too anterior OPG fault”:
“A Front Blur Squeeze”
A: Anterior teeth positioned too forward.
Front: Teeth closer to the front of the film.
Blur: Images of the teeth are blurred because they’re outside the focal trough.
Squeeze: Teeth appear squeezed (narrowed) due to less magnification.
Teeth too posterior:
If the incisors are positioned posterior to the notch in the bitestick, they will end up
farther from the film, which passes in front of the patient. This results in an increase in
the width of the images of the front teeth (more magnification) and, since they are now
slightly outside the focal trough, the images of the teeth will be blurred.
here: Incisors positioned posterior to notch in bite stick. Incisors wider than normal and
blurred.
Teeth too posterior:
If the incisors are positioned posterior to the notch in the bitestick, they will end up
farther from the film, which passes in front of the patient. This results in an increase in
the width of the images of the front teeth (more magnification) and, since they are now
slightly outside the focal trough, the images of the teeth will be blurred.
here: The anterior teeth are positioned behind the bite groove, causing them to appear wider
than norm
Chin tipped down too much. Roots of mandibular incisors shortened. V-shaped
mandible.
Here’s a mnemonic for “head tipped down OPG fault”:
“Downward V Short”
Downward: Head tipped down too much.
V: Mandible appears V-shaped on the film.
Short: Shortening of mandibular incisors occurs.
This mnemonic captures the cause (downward tilt) and the key effects (V-shaped mandible and shortened incisors) in a concise and memorable way.
Patient’s chin is tilted downward leading to appearance of a “Cheshire cat grin” due to
the accentuated Curve of Spee.
“Downward V Short”
Downward: Head tipped down too much.
V: Mandible appears V-shaped on the film.
Short: Shortening of mandibular incisors occurs.
The patient’s chin is too low. The occlusal plane is “smiling” and the apices of the
mandibular incisors are fuzzy
Chin tipped up too much. Hard palate superimposed over roots of maxillary teeth.
Squared-off mandible. “Reverse Smile”.
Here’s a mnemonic for “head tipped up OPG fault”:
“Up Square Reverse Smile”
Up: Head tipped up too much.
Square: Mandible appears squared-off on the film.
Reverse Smile: A “reverse smile” curve is seen.
Superimposed: Hard palate is superimposed over the roots of maxillary teeth.
This mnemonic highlights the cause (upward tilt) and the main effects (squared mandible, reverse smile, and superimposed hard palate) for easy recall.
Patient’s chin is tilted upward leading to appearance as that of a wide “grimace” due to
a flattened Curve of Spee.
patient’s chin is too high, causing a flat occlusal plane, splayed condyles, and loss
of sharpness of the maxillary incisors.
“Up Square Reverse Smile”
Up: Head tipped up too much.
Square: Mandible appears squared-off on the film.
Reverse Smile: A “reverse smile” curve is seen.
Superimposed: Hard palate is superimposed over the roots of maxillary teeth.
The cervical spine is slumped, appearing as a pyramid-shaped opacity, centered at the
lower half of the film.
“Slouching Spine Shadow”
Slouching: Caused by the patient slouching.
Spine: Shadow of the vertebral column appears on the film.
Shadow: White shadow in the center, but faint outlines of teeth and bone are visible.
“Slouching Spine Shadow”
Slouching: Caused by the patient slouching.
Spine: Shadow of the vertebral column appears on the film.
Shadow: White shadow in the center, but faint outlines of teeth and bone are visible.
Ghost images of earrings. The ghost image (see “a-g” above) has the same shape and
orientation, but is higher, larger and on the opposite side when compared to the image
of the actual object (see “a” above).
The red arrows above point to the ghost image of the left side of the patient’s
mandible.
Here’s a mnemonic for “Palatoglossal Air Space OPG fault”:
“Tongue Down, Band Blocks”
Tongue Down: Tongue not kept against the palate during exposure.
Band: Radiolucent band (air space) appears on the film.
Blocks: The band can block or mask periapical radiolucencies.
This mnemonic highlights the problem (tongue position) and the key consequence (masked radiolucencies) for easy recall.
ere’s a mnemonic for “Lip Space OPG fault”:
“Lips Open, Shadow Masks”
Lips Open: Patient doesn’t close their lips on the bite block.
Shadow: Radiolucent shadow (lip space) appears on the film.
Masks: The shadow masks the crowns of anterior teeth.
Failure to remove complete upper denture before exposure. This is usually not a
problem since the denture acrylic is not dense enough to block the image of the
maxillary bone.
Leaving partial dentures in the mouth for a panoramic film will usually obscure
important diagnostic information as seen in the above film. Note the hearing aid in the
left ear (green arrow) and its ghost image overlying the right orbit (red arrows).
Failure to remove glasses. Also note squared-off mandible and reverse “smile”,
indicating chin tipped up too much.
Patient movement.
Radiograph shows image distortion due to patient movement during exposure.
Slight patient movement indicated by notching of mandible at arrow.
