Paranasal Sinuses and Facial Bones Review Flashcards
Which sinus group is of primary importance in the lateral projection of the sinuses?
Sphenoidal
Which sinus groups are best demonstrated with the PA axial projection, Caldwell method?
Frontal and anterior ethmoidal
Where should petrous ridges be seen in the image of the PA axial projection, Caldwell method, of the sinuses?
Lower third of the orbits
Which positioning line should form an angle of 37 degrees with the IR for the paritoacanthial projection, Waters method?
Orbitomeatal
Which paranasal sinus group is best demonstrated with parietoacanthial projection, Waters method?
Maxillary
Which sinus group is not well demonstrated in the image produced by the parietoacanthial projection, Waters method?
Sphenoidal
Which two paranasal sinus groups are better demonstrated with the SMV projection than are the other sinuses?
Ethmoidal and shpenoidal
Which projection of the sinuses demonstrates a symmetric image of the anterior portion of the base of the skull?
SMV
In which projection of the sinuses must the OML form an angle of 15 degrees with the plane of the IR?
PA axial, Caldwell method
Which evaluation criterion pertains to the lateral projection of the paranasal sinuses?
All four sinus groups should be included
Which evaluation criterion pertains to the PA axial projection, Cladwell method, of the sinuses?
The frontal and ethmoidal sinuses should be seen
Which evaluation criterion pertains to the parietoacanthial projection, Waters method, for paranasal sinuses?
Petrous ridges should lie immediately below the floor of the maxillary sinuses.
Which evaluation criterion pertains to the SMV projection for sinuses?
Mandibular condyles should be anterior to the petrous ridges.
With reference to the patient, where should the central ray be directed for the lateral projection of the facial bones?
Zygomatic bone
With reference to the IR, how should the central ray be directed for the parietoacanthial projection, Water method?
Perpendicular
Which evaluation criterion pertains to the PA axial projection, Caldwell method?
The distance between the lateral border of the skull and orbit should be the same on both sides.
Which evaluation criterion pertains to the SMV projection for bilateral zygomatic arches?
The zygomatic arches should be free from overlying structures.
A modified Towne method of the bilateral zygomatic arches produces an image similar to the Towne method of the skull. How many degrees and in what direction should the central ray be directed for this projection to demonstrate zygomatic arches when the OML is perpendicular to the IR?
30 degrees caudad
Where should modified Towne projection be directed at?
Glabella
To demonstrate the mandibular body with the axialolateral oblique projection, how should the patient’s head be positioned?
From true lateral, rotate the head 30 degrees toward the IR
How many degrees and in which direction should the central ray be directed for the axiolateral projection of the mandible?
25 degrees cephalad
Which projection is performed with the patient’s head positioned true lateral and the central ray directed 25 degrees cephalad?
Axiolateral projection of the mandible
Which evaluation criterion pertains to the axiolateral oblique projection of the mandible?
The opposite side of the mandible should not overlap the ramus
Which structure is of primary interest when the patient’s head is rotated 15 degree toward the IR from a true lateral position and the central ray is directed 15 degrees caudad, entering about 1.5 inches superior to the upside EAM?
TMJ
For the AP axial projection of the TMJs, where should the central ray be directed?
3 inches above the nasion
Which structures should always be radiographed with the patient in an upright position?
Paranasal sinuses
Which position is the only projection for paranasal sinuses that adepuately demonstrates all four sinus groups?
Lateral
For the PA axial projection, Caldwell method, of the sinuses, which positioning line, in addition to the midsagittal plane, should be perpendicular to the IR?
Orbitomeatal
Which reference to the IR, how should the central ray be directed for the parietoacanthial projection, Waters method?
Perpendicular
Where should the central ray exit the head for the parietoacanthial projection, Waters method?
Acanthion
In which projection of the sinuses is the IR centered to the nasion?
PA axial, Caldwell method
Which evaluation criterion pertains to the lateral projection of the paranasal sinuses?
The orbital roofs should be superimposed
Which evaluation criterion pertains to the PA axial projection, Caldwell method, of the sinuses?
The frontal and ethmoidal sinuses should be seen.
Which evaluation criterion pertains to the PA axial projection, Caldwell method, for sinuses?
Petrous ridges should lie in the lower third of the orbits
Which evaluation criterion pertains to the SMV projection for paranasal sinuses?
Mental protuberance should superimpose anterior frontal bone.
Which positioning line and angle indicate correct positioning of the head for the parietoacanthial projection, Water method?
OML; 37 degrees to the IR
Which evaluation criterion pertains to the PA axial projection, Caldwell method?
The distance between the lateral border of the skull and orbits should be the same on both sides.
With reference to the IR, how should the midsagittal plane be adjusted for the tangential projection demonstrating an individual zygomatic arch?
15 degrees from perpendicular
Which of the following structures can be well demonstrated with an axiolateral oblique projection?
TMJs
How many degrees and in which direction should the central ray be directed for the axiolateral oblique projection for TMJs?
15 degrees caudad
With reference to the patient, where should the IR be centered for the axiolateral oblique projection of the TMJs?
.5 inches anterior to the EAM
