Transcript RADT 1522 Orbits, Facial Bones and Nasal Bones

RADT 1522
Orbits, Facial Bones and
Nasal Bones
Wynn Harrison, MEd
Facial Anatomy

14 facial bones (How Many of Each)
– Maxilla
- Vomer
– Zygomatic
- Mandible
– Palatine
– Nasal
– Lacrimal
– Inferior Nasal Conchae
Mid-saggital view
New Words
 Blow-Out
Fracture – Impact
fracture (Trauma) of the orbital floor
resulting in orbital intrusion into
the maxillary sinus.
*** Look at the orbits carefully, since
60 - 70 % of all facial fractures
involve the orbit in some way



Le Fort I - tooth bearing portion separated
from upper maxilla
Le Fort II - fracture across orbital floor
and nasal bridge (pyramidal fracture)
Le Fort III - fracture across
frontozygomatic suture line, entire orbit
and nasal bridge (craniofacial separation)

LeFort Type I

LeFort Type II

LeFort Type III

Tripod Fracture –
A fracture in which
the zygoma is
separated from its
attachment to the
maxilla, frontal and
temporal bones
 Bell’s
Palsy - Bell's palsy is a
weakness or paralysis of the muscles
that control expression on one side
of your face.
Orbits

Rhese View- Midsagittal plane forms
a 53 degree angle with IR. Chin,
cheek and nose on the table (threepoint landing!) Acanthiomeatal line
perpendicular to IR. Optic foramen
should be seen in center of image.
Foreign Body



PA and Lateral views
are performed to look
for foreign body in the
orbit.
What do you think you
need to have them do
differently for this
exam?
Look UP, Look Down
Nasolacrimal System
Lateral
image post
injection
Injection
Site
Facial Bones Imaging
Caldwell or PA image
Lateral
Waters
Radiographic Views
PA (Caldwell)
 Tuck
patient’s chin; nose and
forehead on table/wall bucky
 OML
 15
perpendicular to IR
degree caudal angulation
 Petrous
pyramids BELOW inferior
orbital margin
Caldwell (use horizontal ray)
Caldwell for facial bones
PA (Caldwell)
Calcified
meningioma
 Lateral
– External auditory meatus
externally and mandible inferiorly
with supracillary arch superiorly in
view.
 CR centered to zygoma, midway
between outer canthus and EAM
 Midsagittal plane is parallel to IR
 IPL is perpendicular to IR
Lateral facial bones
What ‘Bout Technique!!!
Would
you increase or
decrease technique for
lateral facial bones
compared to a lateral
skull?
Water’s View
Midsagittal plane
perpendicular to IR
 IPL parallel to IR
 OML makes 37
degree angle with IR


COLLIMATE!!!!
Waters for facial bones
Modified Parietoacanthial
(Modified Waters)
 OML
55 degrees to the IR
 Chin and nose on table
 Petrous pyramids are seen midmaxillary sinus
 CR exits acanthion
 See
pg. 355 (Merrill’s 12th Edition)
Reverse Water’s View
 Used
when patient cannot be placed
in prone position.
 Mentalmeatal line perpendicular to IR
 CR perpendicular; enters acanthion
 CR parallel to acanthiomeatal line
 Merrill’s
pg. 332-3 (12th Ed)
Nasal Bones
Lateral and Superior/Inferior Views

Lateral: Position exactly like
you would for a lateral skull …
CR ½ inch inferior to nasion.

CR Perpendicular to IR

COLLIMATE
Hyper extended waters
Axial Nasal Bones
 Use
occlusal film. Patient holds film
in teeth. NOT DONE ANYMORE. 
 CR
perpendicular to film
CR
Zygomatic Arches
Bilateral Arches - SMV
 IOML
to CR
 CR
parallel to IR and perpendicular
midsaggital and collimate to
outer edges of zygoma
fracture
Oblique Tangential

Same position as
SMV except head
tilt 15 degrees
toward side of
interest
(Merrill’s p. 337 12
ed)
May View (tangential)


PA positioning; IOML perpendicular to CR,
head tilt 15 degrees away from the area of
interest.
CR bisects zygomatic arch
Shows single zygomatic arch, free of
superimposition

(P. 341-2,
12 Ed. Merrill’s )
Unilateral arch view
C-arm tangential image