Facial Bones Flashcards
SID for facial bones
40”
Position for PA Caldwell Facial Bones
Prone or PA Erect MSP perpendicular to midline of table Adjust head so that the OML is perpendicular to the IR Nose and forehead against the IR. Nasion is at the center of IR
Textbook CR for PA Caldwell Facial Bones
Angle 15 degrees caudal
Exits nasion
SFMC CR for PA Caldwell Facial Bones
Angle 27 degrees caudal
Exits nasion
Film for PACaldwell
10 x 12 LW Bucky
Structures shown PA Caldwell Facial Bones
Orbital rim Maxillae Nasal septum Zygoma Anterior nasal spine Looking at floor of orbit
The textbook angle for PA Caldwell shows
Petrous pyramids in lower 1/3 of orbits
SFMC angle for PA Caldwell shows
Petrous pyramids within the maxillary sinuses; below orbits
This angle will show the orbital floor better.
Rotation for PA Caldwell shows
MLOM
Sides of skull are equal distance to lateral borders of orbits
MSP of head aligned with long axis of collimating field.
Routine for facial bones
PA Caldwell
Waters
Lateral on affected side
Base view for zygoma
Waters is aka
Parietoacanthial Projection
Position for Waters for Facial Bones
Prone or PA Erect seated.
MSP to midline of IR.
Adjust head until the OML forms a 37 degree angle with IR.
Place the tip of the Chin up and against IR.
Mentomeatal line is adjusted so it is perpendicular to the IR.
Center the IR at the level of the acanthion.
CR Waters Facial Bones
Perpendicular to IR exiting the acanthion.
Acanthion is at center of IR.
Film Waters
10 x 12 LW Bucky
Structures Waters Facial Bones
Entire rim of orbits
Entire Facial bones
Petrous ridges projected immediately below maxillary sinuses.
Maxillae
Bony nasal septum
Zygoma
Maxillary sinuses
Rotation for Waters
MLOM
Sides of skull
Position for Lateral Facial Bones
Semi-prone or erect with body in an anterior oblique position.
Place head in a true lateral position.
MSP is parallel to the IR
Interpupillary is perpendicular to the IR.
CR for Lateral Facial Bones
CR centered and perpendicular to the zygoma.
Entering lateral surface of zygoma halfway between outer canthus and EAM.
Film for Lateral
10 x 12 LW Bucky
Structures for Lateral Facial Bones
Superimposed facial bones and orbital plates. Sella tursica Zygoma Mandible Maxillae
Rotation for Lateral
Look at mandible
How do we tell if there’a any Tilt for Lateral facial bones
Look at orbital plates
Base view of Zygoma is aka
Submental view or Submentovertical Projection
Base view of Zygoma position
Raise chin and hyperextend neck until the IOML is parallel to the IR.
Patient supine and angle sponge to angle neck back.
CR for Base view of Zygoma
CR perpendicular to IOML at level of zygomatic arches
CR entering the MSP of the throat at the level approximately 1” posterior to the outer canthi.
Film for Base view of Zygoma
10 x 12 LW out of Bucky
Prop up a cassette so it is touching top of head.
Structures seen for Base view of Zygoma
Zygomatic arches and symmetrical.
How do we adjust technique for Base view of Zygoma
Since it they are thin bones, decrease technical factors.
5 mAs at 70 kVp
If we can only see one of the zygomatic arches well during, base view of Zygoma then what do we do?
Oblique Inferosuperior (tangential).
Describe Oblique Inferosuperior (tangential) for zygomatic arch
SMV position
Rotate MSP patient head toward affected side 15 degrees.
Tilt top of head 15 degrees away from side being examined.
Skim CR through zygomatic arch on affected side.
What view shows orbits better?
Modified Waters
With OML 55 degrees to IR
What is an optional Zygomatic Arch view
AP Axial
Position for AP Axial Zygomatic arches
Position like AP Axial Townes:
Patient seated upright or supine position.
MSP centered to midline of the grid.
OML is perpendicular to IR
CR for AP Axial Zygomatic arches
CR to 1” above glabella
Textbook says CR to enter the glabella 1” above the nasion at an angle 30 degrees caudal.
and CR passed directly through Zygomatic Arches
CR 30 degrees to OML
If patient cannot flex neck enough, then CR 37 degrees to IOML.
Orbits Routine
PA Caldwell
Modified Waters Erect if possible
Lateral of Affected Side