Download Mandible Lecture - El Camino College

Week 7 :Mandible
Week 8 : TMJ
RT 233 Week 7 & 8
(FINAL)
Mandible
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Mandible (Slide 3)
1. Only movable bone
in the skull
2. Densest & largest
facial bone
3. 2 bones at birth
4. Contains mental
foramina
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Temporomandibular Joint
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Indications
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2
3
PA Mandible (rami)
1. ________ or ________
2. _________________
and nose on IR
3. ________& ________
perpendicular to IR
4. CR perpendicular to exit
_____________
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PA Mandible (rami) Radiograph
1. Mandibular ________
2. ________ portion of
______ are visualized
3. Entire mandible without
_________ or _________
4. _________ or __________
displacement
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PA Mandible Rami- Diagram
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PA Mandible (body)
1. ________or _______
2. ____ and ____ on grid
device or table
– Mandibular symphysis
______with plane of IR
3. ___ & ___ perpendicular to
IR
4. CR perpendicular to level of
________
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PA Mandible (body) Radiograph
1. Contrast and density
are sufficient to view
body and rami
2. Sharp bony detail
indicating no motion
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PA Axial (rami)
Mandible Positioning
1. Seated or _______
2. Forehead and _____
on IR
3. _____ & MSP
perpendicular to IR
4. CR 20- 25
_________, centered
to exit
_______________
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PA Axial (rami)
Mandible Radiographs
1. Heads of ________
are visible through
______ processes.
2. Condyloid
processes are
slightly _________.
3. Proper density
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4. No rotation or tilt
PA Axial (body)
Mandible Positioning
1. Seated or Prone
2. ____ and ____on
grid device or table
–
mandibular symphysis
___________ with IR
3. ____ & _____
perpendicular to IR
4. CR between TMJ’s,
30 ____________
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PA Axial (body)
Mandible Radiographs
1. TMJ’s just ________
to mastoid process
2. Symmetric ______
3. Adequate contrast
and density
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Axiolateral Oblique Positioning for
Ramus
1. Seated, semiprone or
semisupine
2. IPL ____________ to IR
3. Mouth closed- _________
together
4. Extend neck, chin
___________forward
5. CR __ degrees _____to pass
through area of interest
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Axiolateral Oblique Radiograph for
Ramus
1. No overlap of ramus
by opposite side of
mandible
2. No elongation or
foreshortening of
ramus
3. No superimposition
of ramus by c-spine
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Axiolateral Oblique Positioning for
Body
1. Seated, semiprone or
semisupine
2. IPL perpendicular to IR
3. Mouth closed- teeth
together
4. Extend neck, chin jutted
forward
5. Rotate pt’s head
_________ degrees toward
IR
6. CR 25 degrees cephalic to
pass through area of
interest
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Axiolateral Oblique Radiograph for
Body
1. No overlap of body
by opposite side of
mandible
2. No elongation or
foreshortening of
body
3. No superimposition
of body by c-spine
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Axiolateral Oblique Positioning for
Mandibular Symphysis
1. Seated, semiprone or
semisupine
2. IPL perpendicular to IR
3. Mouth closed- teeth together
4. Extend neck, chin jutted
forward
5. Rotate pt’s head __ degrees
toward IR
6. CR 25 degrees cephalic to
pass through area of interest
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Axiolateral Oblique Radiograph for
Mandibular symphysis
1. No overlap of
mentum by the
opposite side of
mandible
2. No foreshortening of
the mentum region
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SMV Mandible
• IOML parallel to IR
• Shows coronoid and
condylod processes
orf rami
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SMV
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SMV Radiograph
• Condyles anterior to
pars petrosae
• Symphysis extended
almost past border of
face
• Equal distance from
condyles to lateral
margin of skull
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Panorex Mandible
1. Explain how tube/image
receptor move
2. IOML perpendicular
3. Stand straight, not jutting
chin forward
4. Instruct pt to keep lips
together and tongue on
roof of mouth
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Panorex Mandible Radiographs
1. Demonstrates teeth,
mandible, TMJ’s
2. Density are uniform
across image
3. No artifacts
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Fractures and Surgical Repair
Surgical Fixation
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Jaw wired shut
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Temporomandibular
Articulations
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1. Supine or seated upright
2. Posterior teeth closed and
in contact
3. For open mouth- wide as
possible without chin
jutted forward
4. OML perp to IR
5. CR 35 caudad, centered
midway between TMJ’s.
6. Enters approx 3” above
nasion
AP Axial
TMJ
AP Axial TMJ Radiograph
1. No rotation
2. Minimal
superimposition of
petrosa on condyle in
closed mouth
3. Condyle and TMJ
below pars petrosa in
open mouth
1. Semiprone or seated
2. Center ½” anterior to
EAM
3. Rest cheek on grid
device
4. Rotate MSP approx 15
degrees toward IR
5. IPL perpendicular
6. CR 15 caudad exiting
through TMJ closest to
IR about 1 ½ “
superior to upside
EAM
Axiolateral
Oblique TMJ
Axiolateral Oblique TMJ
Radiograph
1. TMJ
2. Condyle lying in
mandibular fossa in
closed mouth
3. Condyle lying inferior
to articular tubercle
in open mouth
Axiolateral Oblique Open mouth
Axiolateral Oblique Open mouth
Temporomandibular
fossa
condyle
Coronoid
Axiolateral Oblique
Closed mouth
Axiolateral Oblique
Closed mouth
Temporomandibular
fossa
condyle
coronoid
Axiolateral TMJ’s
• CR 25-30 degrees
• Enters ½” anterior and 2”
superior to upside EAM
• IPL Perpendicular
• MSP parallel
Evaluation Criteria
• TMJ lying anterior to the EAM
• Condyle in fossa (closed mouth)
• Condyle inrerfior to articular tubercle (open
mouthP
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Axiolateral Closed Mouth
Axiolateral Open Mouth