radt 1522 orbits, facial bones and nasal bones

RADT 1522RADT 1522Orbits, Facial Bones and Orbits, Facial Bones and

Nasal BonesNasal Bones

Wynn Harrison, MEdWynn Harrison, MEd

Facial AnatomyFacial Anatomy

14 facial bones (How Many of Each)14 facial bones (How Many of Each)– Maxilla Maxilla - Vomer- Vomer– Zygomatic Zygomatic - Mandible- Mandible– PalatinePalatine– NasalNasal– LacrimalLacrimal– Inferior Nasal ConchaeInferior Nasal Conchae

Mid-saggital viewMid-saggital view

New WordsNew Words

Blow-Out FractureBlow-Out Fracture – Impact – Impact fracture (Trauma) of the orbital floor fracture (Trauma) of the orbital floor

resulting in orbital intrusion into resulting in orbital intrusion into the maxillary sinus.the maxillary sinus.

*** Look at the orbits carefully, since *** Look at the orbits carefully, since

60 - 70 % of all facial fractures 60 - 70 % of all facial fractures involve the orbit in some way involve the orbit in some way

Le Fort I - tooth bearing portion separated Le Fort I - tooth bearing portion separated from upper maxilla from upper maxilla

Le Fort II - fracture across orbital floor and Le Fort II - fracture across orbital floor and nasal bridge (pyramidal fracture) nasal bridge (pyramidal fracture)

Le Fort III - fracture across Le Fort III - fracture across frontozygomatic suture line, entire orbit frontozygomatic suture line, entire orbit and nasal bridge (craniofacial separation) and nasal bridge (craniofacial separation)

LeFort Type ILeFort Type I

LeFort Type IILeFort Type II

LeFort Type IIILeFort Type III

Tripod FractureTripod Fracture – – A fracture in which A fracture in which the zygoma is the zygoma is separated from its separated from its attachment to the attachment to the maxilla, frontal and maxilla, frontal and temporal bonestemporal bones

Bell’s PalsyBell’s Palsy - Bell's palsy is a - Bell's palsy is a weakness or paralysis of the muscles weakness or paralysis of the muscles that control expression on one side that control expression on one side of your face.of your face.

OrbitsOrbits Rhese View- Midsagittal plane forms Rhese View- Midsagittal plane forms

a 53 degree angle with IR. Chin, a 53 degree angle with IR. Chin, cheek and nose on the table (three-cheek and nose on the table (three-point landing!) Acanthiomeatal line point landing!) Acanthiomeatal line perpendicular to IR. Optic foramen perpendicular to IR. Optic foramen should be seen in center of image.should be seen in center of image.

Foreign Body Foreign Body

PA and Lateral views PA and Lateral views are performed to look are performed to look for foreign body in the for foreign body in the orbit. orbit.

What do you think you What do you think you need to have them do need to have them do differently for this differently for this exam?exam?

Look UP, Look Down Look UP, Look Down

Nasolacrimal SystemNasolacrimal System

Injection Site

Lateral image post injection

Facial Bones ImagingFacial Bones Imaging

Caldwell or PA imageCaldwell or PA image

LateralLateral

WatersWaters

Radiographic ViewsRadiographic ViewsPA (Caldwell)PA (Caldwell)

Tuck patient’s chin; nose and Tuck patient’s chin; nose and

forehead on table/wall buckyforehead on table/wall bucky

OML perpendicular to IROML perpendicular to IR

15 degree caudal angulation15 degree caudal angulation

Petrous pyramids BELOW inferior Petrous pyramids BELOW inferior orbital marginorbital margin

Caldwell (use horizontal ray)Caldwell (use horizontal ray)

Caldwell for facial bonesCaldwell for facial bones

PA (Caldwell)PA (Caldwell)

Calcified meningioma

Lateral Lateral – External auditory meatus – External auditory meatus externally and mandible inferiorly externally and mandible inferiorly with supracillary arch superiorly in with supracillary arch superiorly in view. view.

CR centered to zygoma, midway CR centered to zygoma, midway between outer canthus and EAMbetween outer canthus and EAM

Midsagittal plane is parallel to IRMidsagittal plane is parallel to IR IPL is perpendicular to IRIPL is perpendicular to IR

Lateral facial bonesLateral facial bones

What ‘Bout Technique!!!What ‘Bout Technique!!!

Would you increase or Would you increase or decrease technique for decrease technique for lateral facial bones lateral facial bones compared to a lateral compared to a lateral skull?skull?

Water’s ViewWater’s View Midsagittal plane Midsagittal plane

perpendicular to IRperpendicular to IR IPL parallel to IRIPL parallel to IR OML makes 37 OML makes 37

degree angle with IRdegree angle with IR

COLLIMATE!!!!COLLIMATE!!!!

Waters for facial bonesWaters for facial bones

Modified Parietoacanthial Modified Parietoacanthial (Modified Waters)(Modified Waters)

OML 55 degrees to the IROML 55 degrees to the IR Chin and nose on tableChin and nose on table Petrous pyramids are seen mid-Petrous pyramids are seen mid-

maxillary sinusmaxillary sinus CR exits acanthionCR exits acanthion

See pg. 355 (Merrill’s 12See pg. 355 (Merrill’s 12thth Edition) Edition)

Reverse Water’s ViewReverse Water’s View

Used when patient cannot be placed Used when patient cannot be placed in prone position.in prone position.

Mentalmeatal line perpendicular to IRMentalmeatal line perpendicular to IR CR perpendicular; enters acanthionCR perpendicular; enters acanthion CR parallel to acanthiomeatal lineCR parallel to acanthiomeatal line

Merrill’s pg. 332-3 (12Merrill’s pg. 332-3 (12thth Ed) Ed)

Nasal BonesNasal BonesLateral and Superior/Inferior ViewsLateral and Superior/Inferior Views

Lateral: Position exactly like Lateral: Position exactly like you would for a lateral skull … you would for a lateral skull … CR ½ inch inferior to nasion. CR ½ inch inferior to nasion.

CR Perpendicular to IRCR Perpendicular to IR

COLLIMATECOLLIMATE

Hyper extended watersHyper extended waters

Axial Nasal BonesAxial Nasal Bones

Use occlusal film. Patient holds film Use occlusal film. Patient holds film in teeth. NOT DONE ANYMORE. in teeth. NOT DONE ANYMORE.

CR perpendicular to film CR perpendicular to film

CR

Zygomatic ArchesZygomatic Arches

Bilateral Arches - SMVBilateral Arches - SMV

IOML parallel to IR and perpendicular IOML parallel to IR and perpendicular to CRto CR

CR midsaggital and collimate to CR midsaggital and collimate to outer edges of zygomaouter edges of zygoma

fracture

Oblique TangentialOblique Tangential

Same position as Same position as SMV except head SMV except head tilt 15 degrees tilt 15 degrees toward side of toward side of interestinterest

(Merrill’s p. 337 12 (Merrill’s p. 337 12 ed)ed)

May View (tangential)May View (tangential) PA positioning; IOML perpendicular to CR, PA positioning; IOML perpendicular to CR,

head tilt 15 degrees away from the area of head tilt 15 degrees away from the area of interest. interest.

CR bisects zygomatic archCR bisects zygomatic arch

Shows single zygomatic arch, free of Shows single zygomatic arch, free of superimpositionsuperimposition

(P. 341-2, 12 Ed. Merrill’s )(P. 341-2, 12 Ed. Merrill’s )

Unilateral arch viewUnilateral arch view

C-arm tangential imageC-arm tangential image