1. MANDIBLE
RT 233

2. MANDIBLE ANATOMY rami coronoid process body mental foramen
condyle mental symphysis
alveolar process mentum
mental protuberance

3. Mandible
Mandible starts out as two ossification centers, fuses into one bone sometime during the first year of life

4. Mandible

5. Mandible Indications for x-ray Fractures Neoplastic Processes
Inflammatory Processes
2nd most commonly fractured bone of face
• most mandibular fractures occur at a single location
• multiple fractures and/or TMJ dislocations are common
• majority occur in body
– often associated w/ a contralateral condylar process fracture
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Most mandibular fractures are a result of MVA, second most common cause-fist fight

6. Mandible

7. Essential Projections: Mandible
PA – rami
PA-body
PA axial – rami
PA axial-body
Axiolateral obliques for rami, body, symphysis

8. Additional Projections
SMV
AP Axial (Townes)
True Lateral

9. PA Mandible (for rami)
Entry point for CR is roughly just distal to occiput
Collimate to include TEA, lower mandible

10. Mandible-PA (for rami)
Mandibular rami
Lateral portion of body are visualized
Demonstrate the entire mandible without rotation or tilt
Will show medial or lateral displacement of fractures

11. PA Mandible Rami- Diagram

12. Projection??

13. Projection?
Justify your answer

14. Mandible-PA (for body)
Very similar to Waters but not as much extension, use LML
Entry point for CR is base of occiput

15. Mandible-PA (for body)
Contrast and density are sufficient to view body and rami
Sharp bony detail indicating no motion

16. Projection?
Identify labels:…..

17. Mandible-PA Axial (for rami)
CR entry is close to C7, T1, collimate to include EAM

18. Mandible- PA Axial (for rami)
Heads of condyles are visible through mastoid processes.
Condyloid processes are well visualized, slightly elongated.
Proper Density
No rotation or tilt

20. PA Axial (body) Mandible Positioning
CR passes thru EAMs, exits LML, near acanthion

21. PA Axial (body) Mandible Radiographs
TMJ’s just inferior to mastoid process
Symmetric rami
Adequate contrast and density

22. AP Axial – Towne Method
IF the area of interest is the TM fossae angle the CR 40 degrees to the OML to reduce superimposition of the TM fossae and mastoid portions of the temporal bone.

23. AP Axial- Towne Method Radiograph
Demonstrates condyloid processes symmetrically
Clear visualization of TMJ fossae and condyle relationship
Minimal SI of TM fossae and mastoid portions

25. Axiolateral Oblique Positioning for Ramus
Center downside to cassette, off-set cassette if needed for CR angle.
Enter CR just below upside Body, near 1st molar

26. Axiolateral Oblique Radiograph for Ramus
No overlap of ramus by opposite side of
mandible
No elongation or foreshortening of ramus
No superimposition
of ramus by c-spine
Note foreshortening of body

27. Axiolateral Oblique Positioning for Body
Place chin and cheek on long axis of cassette/Bucky
Keep shoulders depressed, keep body near Bucky,
If needed, tilt head toward bucky, decrease CR angle correspondingly

28. Axiolateral Oblique Radiograph for Body
No overlap of body by opposite side of mandible
No elongation or foreshortening of body
No superimposition of body by c-spine
Note overlap of Hyoid Bone

29. Axiolateral Oblique Positioning for Mandibular Symphysis

30. Axiolateral Oblique Radiograph for Mandibular symphysis
No overlap of mentum by the opposite side of mandible
No foreshortening of the mentum region

31. Mandible
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39. Mandible
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46. Panorex Mandible

47. Panorex Mandible Radiographs
Demonstrates teeth, mandible, TMJ’s
Density are uniform across image
No artifacts