IA 8 TEST

Best demonstrated on Lateral Facial Bones:

All facial bones.

Best demonstrated on Parietoacanthial:

Orbits, infraorbital margin, maxillae, nasal septum & zygo arches.

Best demonstrated on SMV and tangential:

Zygomatic Arches.

Best demonstrated on PA & PA axial mandible:

Body and rami of mandible.

Best demonstrated on Axiolateral obl mandible:

Body or mentum - depending on rotation. (30 or 45)

Best demonstrated on Axiolateral mandible:

Ramus

Best demonstrated on the Modified Towne:

Zygomatic arches, rami and TMJ's

AOI on Water's for facial bones:

Facial (orbits, maxillae & zygo arches) or nasal bones

AOI on PA and PA axial mandible:

Mandible

AOI on lateral nasal bones:

Nasal bone closest to the IR.

AOI on the Parieto-Orbital Oblique (Rhese Method):

Orbit closest to the IR.

AOI on the Modified Waters:

Blowout fracture of the orbit.

Which projection best demonstrates the nasal septum?

Parietoacanthial (Water's)

What is the centering point for lateral facial bones?

Midway between the outer canthus and EAM (crosshairs are on the zygoma)

What is the centering point for lateral nasal bones?

1" distal to the nasion

What is the centering point for the lateral skull?

2" superior to the EAM

What is the centering point for the lateral sinuses?

1/2" - 1" posterior to the outer canthus

The CR exits the acanthion on which facial bones projections?

Parietoacanthial, PA Mandible, and PA Axial Mandible

What is the centering point for the SMV for zygo arches?

MSP & 1" posterior to the outer canthus

Where does the CR enter on the Axiolateral mandible?

Ramus (mid-ramus on side of interest, but angle/gonion of ramus that is "up")

Where does the CR enter on the Axiolateral obl mandible?

The mandibular region of interest (body or mentum)

IA Positioning: Parietoacanthial Facial Bones (Water's Method)

- prone or upright

- MML perpendicular to IR

- OML 37 degrees to IR

- petrous pyramids immediately below maxillary sinuses

- equidistant lateral margin of orbit and lateral border of skull

IA Positioning: Lateral Facial Bones

- upright or recumbent

- pt. in RAO or LAO position, head lateral

- orbital roofs SI'ed

- rami practically SI'ed

- sella turcica in profile

IA Positioning: PA Mandible

- pt. upright or prone

- petrous pyramids fill orbits

- equidistant lateral margin of orbit and lateral border of skull

- mandibular rami and bodies symmetrical

- MSP aligned with the long axis

IA Positioning: PA Axial Mandible

- pt. upright or prone

- OML and MSP perpendicular

- equidistant lateral margin of orbit and lateral border of skull

- mandibular rami and bodies symmetrical

- MSP aligned with the long axis

IA Positioning: Axiolateral Mandible for Ramus

- pt. upright or recumbent

- MSP parallel to IR

- head lateral

- IPL perpendicular to IR

- no overlap of ramus by the opposite side of the mandible

- no SI of ramus by C-spine

- no elongation or foreshortening of ramus

IA Positioning: Axiolateral Oblique Mandible for Body

- pt. upright or recumbent

- head obliqued 30 degrees (makes the mandible parallel to the IR)

- no overlap of body by opposite side of mandible

- no elongation or foreshortening of body

IA Positioning: Axiolateral Oblique Mandible for Symphysis

- pt. upright or recumbent

- head obliqued 45 degrees (makes the symphysis/mentum parallel to the IR)

- no overlap of body by opposite side of mandible

- no elongation or foreshortening of body

IA Positioning: Lateral Nasal Bones

- pt. upright or recumbent

- head in a lateral position

- nasal bones are in profile and SI'ed

- no rotation of bones and soft tissue

IA Positioning: SMV for Zygomatic Arches

- pt. upright or supine

- hyperextend the neck

- IOML parallel

- MSP perpendicular to IR

- zygomatic arches symmetrical and without foreshortening

- arches free of SI

IA Positioning: Tangential Zygomatic Arch

- pt. upright or supine

- MSP of head rotated 15 degrees toward the affected side

- Top of the head tilted 15 degrees away from the side being examined

- zygomatic arches in profile and free of SI

IA Positioning: AP Axial Modified Towne

- pt. upright or supine

- OML perpendicular (30 degrees caudal), or IOML perpendicular (37 degrees caudal)

- petrous pyramids symmetrical

- zygomatic arches symmetrical

- no overlap of mandibular arches

- dorsum sella and posterior clinoids seen in the foramen magnum