RADT 1522 - section 3

6/10/2014
MANDIBLE, SINUSES,
TEMPORAL BONE
Rex T. Christensen MHA
Wynn Harrison, MEd
Pathologic Indications for
Facial Radiography
• Fractures
•
•
•
•
Blowout
Tripod
LeFort
Coutrecoup
• Foreign Body
• Osteomyelitis
• Secondary
Osteomyelitis
• TMJ Syndrome
• Neoplasms
NEW WORDS
• Sinusitis: Inflammation of the
sinuses
• Mucocele: Enlargement of the
lacrimal sac. Cystic disease
of the air cavities – causes
erosion of the bone
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• Retention Cyst: A cyst retaining
the secretion of a gland, ie:
mucosal or sebaceous cyst
• Mastoiditis: Inflammation of the
mastoid sinus
• Otitis: Inflammation of the ear:
ie: otitis media; can be
internal or external
• Acoustic Neuroma: benign tumor of
the eighth cranial nerve.
Symptoms = hearing loss, pain,
headache, balance problems.
Paranasal Sinuses
• Air-filled sinuses are located
within
• Frontal bone
• Ethmoid bone
• Sphenoid bone
• Maxillary bones
• Lined with mucous membrane
• Serve to lighten the skull
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Paranasal Sinuses
The mandible is the largest,
densest bone of the face
The Mandible is one of two nonpaired bones of the face
What is the other?
• The Vomer is the other nonpaired facial bone!
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What are the alveolar
processes?
• Spongy bone on superior
surface of mandible
(maxillae) that presents
excavation for reception
of roots of teeth-Sockets
PA Mandible
Lateral Mandible
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Basic Routine Projections for Mandible
PA
Bilateral Axiolateral
Obliques
SMV (optional)
Mandible-PA - Ramus
Mandible-PA-Ramus
 Similar to a PA skullnose and forehead
against IR
 CR- 0 Degrees OML
 Exit at tip of nose
(acanthion)
 8x10 cassette,
collimated
 Body and mentum
superimposed on
spine
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Evaluation Criteria –
Mandible PA Ramus
 Mandibular
body and rami
symmetric
 include entire
mandible
 Interpupillary
line horizontal
 midsag.plane
perpendicular
PA Axial Projection - Ramus
• Forehead and nose on IR
• OML perpendicular to IR
• CR 20-25 degrees cephalad
• CR exits the
acanthion
• Visualizes the
mandibular body
and rami
PA Axial Mandibular
Body and Rami
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PA Mandible - Body
• Similar to PA for
Ramus, except
chin and nose
against IR
• AML
• 0 degree CR
angle
PA Mandible - Body
• Ramus
• Mentum
• Body
• Angle
PA Axial - Body
• Chin and nose on IR
• AML perpendicular to IR
• CR 30 degree cephalad
• Shows mandibular
body and TMJ’s
• Center between
TMJ’s
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Similar to a Townes –
but lower
Mandible- axiolateral oblique
• Both left and right oblique
projections must always be
performed!
• Blow to one side of jaw transfers
force to opposite side, possibly
breaking that side, not necessarily
fracturing side of impact
(Coutrecoup)
Mandible- axiolateral obliques
– 3 variations
• Ramus (lateral)
• Body (30 degrees internally
rotated)
• Symphysis (45 degrees internally
rotated)
CR angled up 25 degrees in all projections!
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Mandibular axiolateral obliques
Body
Ramus
•A
B
Symphysis
C
Mandibular Axiolateral oblique
- Ramus
Head true lateral
CR angled 25
degrees up
Extend chin to avoid
superimposition
on spine
Mandibular Axiolateral oblique
- Ramus
TMJ
A
CONDYLE
B
CORONOID
C
RAMUS
D
BODY
E
ANGLE F
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Axiolateral oblique - Body
 Similar to
ramus oblique,
but rotate head
30 degrees to
IR (mand. Body
of interest will
be parallel to
IR)
 CR 25 degrees
up through
area of interest
Axiolateral oblique - Body
Coronoid •A
Ramus
•B
Body
•C
Hyoid
•D
• Evaluation
criteria
• -no overlap of
body by opposite
body
 no cervical
spine
superimposition
 no distortion of
body
Angle •E
Axiolateral oblique - Symphysis
 No overlap of
mentum
 no
foreshortening
 (spine will
overlap body)
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Mandible - SMV
(optional)
• For visualizing mandibular body
and coronoid & condyloid
processes of rami
Mandible - SMV
• Similar to skull,
but collimated to
anterior portion of
cranium
• IOML parallel to IR
• CR Perpendicular
to IOML, midway
between angles
of mandible
SMV- alternate projection
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Mandible - SMV Evaluation
Criteria
Symphysis
Body
A
B
Coronoid
C
process
Ramus D
Condyle E
Petrous
ridge
F
 Distance
between
lateral border
of skull and
mand. Equal
on both sides
 condyles
anterior to
pars petrosae
 Symphysis
extendng to
anterior
border of face
Temporomandibular
joints
TMJ Syndrome
• Clicking, pain in TMJ
• May indicate dysfunction of the
TMJ
• Caused by inflammation, stress,
muscle spasm, etc.
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Axiolateral
• The Axiolateral
Projection can
be used to
evaluate the
temporal
mandibular
joints and
mastoid air cells
and inner ear.
Axiolateral
• Measure: lateral at
EAM
• Protection: Lead
apron
• SID: 40” Bucky
• Tube angle: 25
degrees caudal
• Film size: 8” x 10”
I.D. up (portrait)
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Axiolateral Protection
for TMJ
• Patient is seated
facing the Bucky. Head
is turned to place the
affected TMJ next to
Bucky.
• Skull should be in a
true lateral position.
Align the TMJ to the
center line of the
Bucky.
• The vertical CR should
be aligned with TMJ
away from film.
Axiolateral Protection
for TMJ
• If the affected TMJ
and the side away
from the Bucky is
aligned with the
Center of the Bucky
and Vertical CR, the
skull will be in the
true lateral position.
• The horizontal CR is
aligned with the
Affected TMJ
(closest to film).
Axiolateral Protection
for TMJ
• Center film to
horizontal CR.
• Collimation: 5” x 5”
• Breathing
instructions: Keep
mouth closed and
don’t breathe move
or swallow.
• Make exposure.
• Let patient breathe
but remain in the
position.
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Axiolateral Protection
for TMJ
• Change cassettes to
a new 8” x 10”
• Ask patient to open
mouth as far as
possible.
• Recheck positioning.
• Breathing
Instructions: With
mouth wide open,
don’t breathe move
or swallow.
• Make exposure and
let patient relax.
Axiolateral Protection
for TMJ
• Open and closed
mouth view are taken
of both TM joints.
• The TMJ closest to
the Bucky will be the
one seen at the center
or top of the film.
• Accurate positioning
is essential to being
able to compare
joints.
Questions?
15

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