Panoramic Errors & Techniques

It is important to look at the zones on a panoramic in a _____ manner.

systematic

• look at them in order from 1-6

What is able to be seen in zone 1?

• maxillary sinus

• nasal septum

What is able to be seen in zone 2?

• condyles

• external auditory meatus

What is able to be seen in zone 3?

• body of ramus

• styloid process

• soft palate

• mandibular notch

• mandibular foramen

What is able to be seen in zone 4?

• hyoid bone

• epiglottis

What is able to be seen in zone 5?

• inferior border of mandible

• mental ridges

What is able to be seen in zone 6?

• hard palate & ghost of hard palate

• teeth

• external oblique ridge

• nasal septum and fossa

• mental foramen

What constitutes a nondiagnostic panoramic image?

• cutting off condyles

• cutting off inferior border of mandible

What is the first thing you should ask yourself after taking a panoramic image?

What is the diagnostic quality?

How should we prep the patient before taking a panoramic image on them?

• take off glasses

• ask to remove any metal: earrings, piercings, etc.

• no neck chains

• no hair accessories below the ear

• no hearing aids -- wait until last instruction to take them out

• no dentures/partials

• **ask before touching head covering

What is the real image (true image)?

occurs when the structure lies between the receptor and rotation center

• appears in correct anatomical location

• EX: teeth, condyles

What is the double image?

occurs when the structure is behind the moving rotation center and is penetrated twice by the x-ray beam

• same proportions as real image, same location but on opposite side

• appears as mirror image of real image

• EX: midline structures (hyoid bone, spine, epiglottis)

What is the ghost image?

occurs when the structure is outside the image layer and close to the x-ray source

• resembles the real image but opposite side, blurred, higher and magnified

• EX: anatomical structures located laterally or centrally (hard palate), objects located laterally or centrally (earrings)

T/F: You always need to retake an image with a ghost image in it.

FALSE

• sometimes -- depends if it is still diagnostic

How does the lead apron appear on a panoramic?

small triangle at bottom

How does the thyroid collar appear on a panoramic?

big, opaque band

• why it is not worn for a panoramic

How should the patient be positioned for a panoramic?

• Spine: as tall as possible with shoulders back

• Teeth: teeth into groove on bite block

• Head: facial planes

• Tongue: completely against roof of mouth

• Lips: closed

• Final instruction

What are the facial planes on a panoramic?

• Midsagittal plane

• Frankfort plane

• Canine plane

What is the midsagittal facial plane?

Imaginary vertical plane that splits the body down the middle, dividing into the left and right side

What happens to the image if the midsagittal plane is not lined up?

the errors present as tilted and/or twisted

• tilted: one of the condyles will be higher than the other

• twisted: one side bigger than the other. the side closest to the receptor will appear smaller

What is the frankfort plane?

imaginary line that passes under the floor of the orbit to the external auditory meatus (or tragus)

What happens to the image if the frankfort plane is not lined up correctly?

errors present as exaggerated smile (when chin is tilted down) or a reverse smile/frown (when chin is tilted up)

What is the canine plane?

determines anterior/posterior positioning in relation to the focal trough

What happens if the canine plane is too far forward?

• thin anterior teeth

• spine shows - condyles get super-imposed

What happens if the canine plane is too far back?

• large wide teeth

• ghost of ramus

• condyles are on edge of photo -- can be cut off

What happens to the image if the patient is slumped over?

x-ray beam passes through cervical spine more than once

• leads to lots of opacity in center

What happens to the image if the tongue is not raised?

band of lucency at top of maxilla

How should you instruct the patient to raise their tongue?

please swallow and hold your tongue completely flat against the roof of your mouth