1. Mandible largest, densest bone of face
home ed

2. PA Mandible

3. Lateral Mandible

4. Mandible is one of two non-paired bones of the face What is the other?
If you said Occipital-
you are wrong! That is a cranial bone!
Vomer is other non-paired facial bone!

5. Basic Routine Projections for MandiblePA
Bilateral Axiolateral Obliques
SMV (optional)

6. Notice- there is no lateral projection- why not?
Two halves of mandible would be superimposed-thus obscuring information for both sides.

7. Mandible-PA - Ramus

8. Mandible-PA-Ramus (General survey)
Similar to a PA skull-nose and forehead against IR
CR- 0 Degrees
Exit at tip of nose (acanthion)
8x10 cassette, collimated
(body and mentum superimposed on spine)

9. Evaluation Criteria - PA Mandible
Mandibular body and rami symmetric
include entire mandible
collimate
Interpupillary line horizontal
midsag.plane perpendicular

10. Dental Dosage
Average person in US is exposed to about 360 mrem per year from background sources
Full mouth series of  dental x rays (18 intraoral exposures) = 36 mrem
1 set of dental x-rays = 1/10th background radiation average person is exposed to yearly
Panorex film = 4 mrem or 1/90th yearly back. radiation

11. Panoramic tomography unit

12. Mandible-PA - Ramus

13. Mandible-PA Ramus Similar to PA skull-nose and forehead against IR
CR- 0 Degrees
Exit at tip of nose (acanthion)
8x10 cassette, collimated
(body and mentum superimposed on spine)

14. Evaluation Criteria - PA Mandible
Include entire mandible
Mandibular body and rami symmetric
Interpupillary line horizontal
midsag.plane perpendicular
Collimated

15. PA Mandible-Body
Similar to PA for Ramus, except chin and nose against IR
0 degree CR angle

16. PA Mandible -Body
Ramus
Mentum
Body
Angle

17. PA - Body PA - Ramus

18. A pretty decent AP mandible can be obtained by doing C-spine odontoid

19. Mandible- axiolateral oblique
Both left and right oblique projections must always be performed!
Blow to one side of jaw transfers force to opposite side, possibly breaking that side, not necessarily fracturing side of impact

20. Mandible- axiolateral obliques – 3 variations
Ramus (lateral)
Body (30 degrees internally rotated)
Symphysis (45 degrees internally rotated)
CR angled up 25 degrees in all projections!

21. Mandibular axiolateral obliques
Ramus
Body
Symphysis
A B C

22. Mandibular Axiolateral oblique for Ramus
Head true lateral
CR angled 25 degrees up
extend chin to avoid superimposition on spine

23. Axiolateral oblique-Ramus
TMJ A
CONDYLE B
CORONOID C
RAMUS D
BODY E
ANGLE F

24. Axiolateral oblique - Mandibular Body
Similar to ramus oblique, but rotate head 30 degrees to IR (mand. Body of interest will be parallel to IR)
CR 25 degrees up through area of interest

25. Axiolateral oblique-mandibular body
Evaluation criteria
-no overlap of body by opposite body
no cervical spine superimposition
no distortion of body
Coronoid A B C D E
Ramus
Body
Hyoid
Angle

26. Mandibular Axiolateral oblique - symphysis
No overlap of mentum
no foreshortening
(spine will overlap body)

27. Mandible-axiolateral oblique
LAO
LPO
Shoulder super-imposition problem!

28. Mandible-axiolateral oblique (tip!)
Why struggle to get patient into zero tilt lateral, and then angle 25 degrees up?
Use tilted head to your advantage!
tilt of head CR angle degrees

29. Mandible -SMV (optional)
For visualizing mandibular body and coronoid & condyloid processes of rami

30. Mandible -SMV
Similar to skull, but collimated to anterior portion of cranium
IOML parallel to IR (tilt cassette forward if possible)
CR Perpendicular to IOML, midway between angles of mandible

31. SMV- alternate projection

32. Mandible- SMV Evaluation Criteria
Distance between lateral border of skull and mand. Equal on both sides
condyles anterior to pars petrosae
Symphysis extendng to anterior border of face
Symphysis A
Body B
Coronoid process C
Ramus D
Condyle E F
Petrous ridge

33. Hyoid Bone!
What is the only bone of the human body that does not articulate with any other bone?

34. Hyoid Bone
Attaches from the styloid processes of temporal bone to tongue
No views to demostrate

35. REVIEW A- Coranoid process B- mandibular fossa C- neck of condyle
D- Condyle
E- condylar process
F- Ramus
G- Gonion
H- Body
I-Alveolar process