Term
| What is the CR angulation for a lateral projection of the nasal bones? |
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Definition
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Term
| Where is the CR directed for a lateral projection of the nasal bones? |
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Definition
| perpendicular to the bridge of the nose at a point 1/2 inch (1.3 cm) distal to the nasion |
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Term
| Lateral nasal bones evaluation criteria: |
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Definition
- no rotation
- anterior nasal spine
- frontonasal suture
- top of collimation at the level of the glabella |
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Term
| Position of part for SMV projection of the zygomatic arches: |
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Definition
- IOML is parallel w/ the the plane of the IR
- MSP perpendicular to IR |
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Term
| How is the CR for an SMV projection of the zygomatic arches? |
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Definition
- perpendicular to IOML
- entering MSP of the throat at a level approximately 1 inch (2.5 cm) posterior to the outer canthi |
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Term
| SMV projection zygomatic arches evaluation criteria: |
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Definition
- zygomatic arches free from overlying structures
- zygomatic arches symmetrical w/out foreshortening
- no rotation |
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Term
| Position of part for tangential projection of a zygomatic arch: |
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Definition
- IOML as parallel as possible w/ the plane of the IR
- rotate the MSP of the head ~ 15 degrees toward the side of interest
- tilt the top of the head ~ 15 degrees away from the side of interest |
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Term
| How is the CR for a tangential projection of a zygomatic arch? |
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Definition
- perpendicular to the IOML
- centered to the zygomatic arch at a point ~ 1 inch (2.5 cm) posterior to the outer canthus |
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Term
| Tangential projection zygomatic arch evaluation criteria: |
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Definition
- zygomatic arch free from overlying structures
- zygomatic arch not overexposed |
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Term
| Position of part for AP axial projection (Modified Towne Method) zygomatic arches: |
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Definition
- OML perpendicular to the plane of the IR
- MSP perpendicular to the plane of the IR |
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Term
| How is the CR for an AP axial projection (Modified Towne Method) zygomatic arches? |
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Definition
- (OML) directed 30 degrees caudad to enter the glabella ~ 1 inch (2.5 cm) above the nasion
- (IOML) same as OML but 37 degrees instead |
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Term
| AP axial projection (Modified Towne Method) zygomatic arches evaluation criteria: |
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Definition
- no overlap of zygomatic arches by mandible
- no rotation evident because arches are symmetric
- *zygomatic arches projected lateral to mandibular rami* |
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Term
| Position of part for PA projection mandibular rami: |
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Definition
| - OML perpendicular to plane of the IR |
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Term
| How is the CR for a PA projection of the mandibular rami? |
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Definition
| - perpendicular to exit the acanthion |
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Term
| The PA projection of the mandibular rami is usually ordered to show what? |
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Definition
| - to show medial or lateral displacement of fragments in fractures of the rami |
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Term
| PA projection mandibular rami evaluation criteria: |
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Definition
- mandibular body and rami symmetrical
- entire mandible |
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Term
| Position of part for PA axial projection of the mandibular rami? |
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Definition
| - OML perpendicular to plane of the IR |
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Term
| How is the CR for a PA axial projection of the mandibular rami? |
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Definition
| - directed 20 - 25 degrees cephalad to exit the acanthion |
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Term
| PA axial projection mandibular rami evaluation criteria: |
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Definition
- mandibular body and rami symmetric on each side
- condylar processes
- entire mandible |
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Term
| The PA axial projection of the mandibular rami is usually ordered to show what? |
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Definition
| - to show medial or lateral displacement of fragments in fractures of the rami |
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Term
| Position of part for PA projection mandibular body: |
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Definition
| - rest the head so that the tip of the nose and chin are touching the bucky - AML is placed nearly perpendicular to the IR plane |
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Term
| How is the CR for a PA projection mandibular body? |
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Definition
| - perpendicular to exit the level of the lips |
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Term
| PA projection mandibular body evaluation criteria: |
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Definition
| - mandibular body symmetric on each side |
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Term
| Position of part for PA axial projection mandibular body: |
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Definition
| - rest the head so that the tip of the nose and chin are touching the bucky - AML is placed nearly perpendicular to the IR plane |
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Term
| How is the CR for a PA axial projection mandibular body? |
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Definition
| - directed midway between the TMJs at an angle of 30 degrees cephalad |
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Term
| PA axial projection mandibular body evaluation criteria: |
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Definition
- TMJs just inferior to the mastoid processes
- symmetric rami |
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Term
| Position of part for axiolateral mandibular ramus: |
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Definition
| - Skull in lateral position - mouth closed w/ teeth together - extend the pt's neck enough that the long axis of the mandibular body is parallel w/ the transverse axis of the IR to prevent superimposition of the c-spine |
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Term
| How is the CR for axiolateral and axiolateral oblique projections of the mandible? |
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Definition
- all directed 25 degrees cephalad to pass directly through the mandibular region of interest
- should enter at approximately the level of the gonion |
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Term
| Position of part for axiolateral oblique mandibular body: |
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Definition
- Skull in lateral position
- mouth closed w/ teeth together
- extend the pt's neck enough that the long axis of the mandibular body is parallel w/ the transverse axis of the IR to prevent superimposition of the c-spine
- rotate the pt's head 30 degrees toward the IR |
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Term
| Position of part for axiolateral oblique mandibular symphysis: |
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Definition
- Skull in lateral position
- mouth closed w/ teeth together
- extend the pt's neck enough that the long axis of the mandibular body is parallel w/ the transverse axis of the IR to prevent superimposition of the c-spine
- rotate the pt's head 45 degrees toward the IR |
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Term
| Axiolateral mandibular ramus and axiolateral oblique mandibular body evaluation criteria: |
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Definition
- no overlap of the ramus by the opposite side of the mandible
- no elongation or foreshortening of ramus or body
- no superimposition of the ramus by the c-spine |
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Term
| Axiolateral oblique mandibular symphysis evaluation criteria: |
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Definition
- no overlap of the mentum region by the opposite side of the mandible
- no foreshortening of the mentum region |
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Term
| Position of part for SMV projection of the mandible: |
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Definition
| - IOML as parallel as possible to plane of the IR |
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Term
| How is the CR for an SMV projection of the mandible: |
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Definition
- perpendicular to the IOML
- centered midway between the angles of the mandible |
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Term
| What structures does the SMV projection of the mandible show? |
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Definition
| - show the coronoid and condyloid processes of the rami |
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Term
| SMV projection mandible evaluation criteria: |
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Definition
- distance between the lateral border of the skull and the mandible equal on both sides
- condyles of the mandible anterior to the pars petrosa
- symphysis extending almost to the anterior border of the face so that the mandible is not foreshortened |
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Term
| Position of part for AP axial projection of the TMJs: |
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Definition
| - flex the pt's neck so that the OML is perpendicular to the plane of the IR - one image w/ mouth closed, another w/ mouth open |
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Term
| How is the CR for an AP axial projection of the TMJs? |
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Definition
- directed 35 degrees caudad
- entering a point ~ 3 inches above the nasion
- centered midway between the TMJs |
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Term
| AP axial projection TMJs evaluation criteria: |
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Definition
- minimal superimposition of petrosa on the condyle in the closed mouth
- condyle and TMJs below pars petrosa in the open-mouth |
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Term
| Position of part for axiolateral projection of the TMJs: |
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Definition
- place pt's head in lateral position
- one image is closed-mouth, one image is open-mouth |
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Term
| How is the CR for an axiolateral projection of the TMJs? |
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Definition
- directed at a 25 - 30 degree caudad angle
- enters about 1/2 anterior and 2 inches superior to the upside EAM |
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Term
| Axiolateral projection TMJs evaluation criteria: |
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Definition
- TMJs anterior to EAM
- Condyle lying in mandibular fossa in the closed-mouth
- Condyle lying inferior to articular tubercle in the open-mouth |
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Term
| Position of part for axiolateral oblique projection of TMJs: |
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Definition
- place pt's head in lateral position
- rotate the MSP of the pt's head 15 degrees toward the IR
- Adjust the flexion of the pt's neck so that the AML is parallel w/ the transverse axis of the IR
- needs closed and open mouth images |
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Term
| How is the CR for an axiolateral oblique projection of the TMJs? |
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Definition
- directed 15 degrees caudad to exit the TMJ closest to the IR
- the CR enters ~ 1.5 inches superior to the upside EAM |
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Term
| Axiolateral oblique projection TMJs evaluation criteria: |
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Definition
- condyle lying in mandibular fossa in the closed-mouth
- condyle lying inferior to articular tubercle in the open-mouth projection |
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Term
| Position of part for parietoorbital oblique (Rhese Method): |
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Definition
- center affected orbit to center of the IR, and rest the zygoma, nose, and chin on the bucky
- AML perpendicular to IR
- MSP of head makes a 53 degree angle w/ the IR |
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Term
| How is the CR for a parietoorbital oblique (Rhese Method)? |
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Definition
| - perpendicular - enters approximately 1" superior and posterior to the TEA - exits the orbit closest to the IR |
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Term
| Parietoorbital oblique (Rhese Method) evaluation criteria: |
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Definition
- optic canal "on end", and the optic foramen lying in the inferior and lateral quadrant of the projected orbit
- entire orbital rim
- supra-orbital margins lying on the same horizontal line |
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