1. Imaging of Facial Trauma
Part 2: Introduction and Anatomy
Rathachai Kaewlai, MD
www.RadiologyInThai.com
Created: January 2007
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2. Outline
 Facial fracture epidemiology  Types of facial fracture
 Nasal bone fracture
 Initial management  Naso-orbital-ethmoid fracture
 Frontal sinus fracture
 Imaging: CT versus radiography  Orbital fracture
 Zygomatic fracture
 Normal anatomy
 Maxillary fracture
 3D  Mandibular fracture
 CT (axial, coronal and sagittal planes)
 Radiography  Imaging approach
 Biomechanics
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3. Plain Film Radiography
 Can be obtained to screen for facial injury if CT is not immediately
available
 If plain film identify a fracture other than a simple nasal bone
fracture, further evaluation by CT is indicated
 Multiple plain film projections are relative to ‘canthomeatal line’; an
imaginary line drawn from outer canthus to external auditory meatus
 Proper positioning (of patient’s head), alignment of x-ray beam is
critical for evaluation because facial skeletal anatomy is complex
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4. Plain Film Radiography
 Remember: plain film is a 2D image of a 3D object
 Overlapping structures significantly obscure anatomic detail
 This problem is solved by standard views (to minimize overlap,
allow visualization of important structures, familiarity for
interpretation)
 Rule of symmetry: two sides of the face are quite symmetrical
 Symmetry is usual, and asymmetry is suspect
 Multiplicity: fractures of facial bones are frequently multiple.
Do not stop looking for others when see one
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5. Plain Film Radiography
 Facial series  Mandible
 Water’s view (PA view with  Oblique view, Towne’s view
cephalad angulation)
 Caldwell view (PA view)  Orthopanthogram
 Towne’s view
 Lateral view
 Base view
 Additional view
 Lateral view of the nasal bone
(nasal technique)
Note: The lecture series are focused on CT scan
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6. Water’s View
The most comprehensive single
projection display
Excellent view of
- Maxilla
- Maxillary sinuses
- Zygoma
- Zygomatic arches
- Rims of orbits, esp. floor
- Nasal bones
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7. Water’s View
Key structures
1 = Frontal sinus
2 = Maxillary sinus
3 = Frontal process of
Zygoma
4 = Body of Zygoma (malar
eminence)
5 = Temporal process of
Zygoma
Dotted line = zygomatico-
frontal suture
Dolan’s lines of reference
Line A, B, C
Rule:
smooth, non-disrupted, same
contour on both sides
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8. Line A
- Begins at inner surface of
zygomatico-frontal suture,
follows orbital surface of
zygoma, maxilla, frontal
process of maxilla and arch
of nasal bone
- If drawn to both sides, the
line is similar to lazy ‘W’ or
half frame of reading glasses
Line B
- egins at lateral and inferior
B
margin of maxilla and
extends along lateral wall of
maxillary sinus and inferior
surface of zygomatic arch
- Ends at glenoid fossa
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9. Line C
- Begins at lateral and inferior
margins of maxilla, extends
along lateral wall of
maxillary sinus and inferior
surface of zygomatic arch
- Ends at glenoid fossa
“Friendly Line”
- Medial half of Line C is the
anterolateral wall of the
maxillary sinus.
- If it is disrupted, the
possibilities of fx include
1) Isolated maxillary
antrum
2) Zygomatico-maxillary
complex (ZMC)
3) LeFort (unilateral or
bilateral)
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10. Caldwell’s View
Excellent view of
- Entire rim of orbit, esp.
superomedial rim
- Ethmoid sinus
- Floor of orbit may be well
seen in petrous bones are
projected below the inferior
orbital rim (not in this
example)
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11. Key structures
1 = Ethmoid sinuses
2 = Orbit
Line A, B, C, D = superior,
2 lateral, inferior and medial
walls of the orbit, respectively
Line E = midline nasal
septum and vomer
Rule:
- Ethmoid sinuses density
should be equal, darker than
orbit
- Smooth non-disrupted
orbital walls
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12. Lateral View
Excellent view of
- Frontal sinus: anterior wall
- Maxillary sinus: anterior
and posterior wall
- Sphenoid sinus
- Pterygoid plate
- Floor of anterior cranial
fossa, hard palate
- Lateral rim of orbit
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13. Key structures
1 = Frontal sinus
2 = Maxillary sinus
3 = Sphenoid sinus
4 = Hard palate
5 = Anterior wall of temporal
fossa
Between green arrows =
Pterygoid plate
Line A = Anterior wall of
frontal sinus
Line B = Anterior cranial
fossa
Line C = Anterior wall of
maxillary sinus
Line D = Posterior wall of
maxillary sinus
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14. Line A
- Connects anterior surface of
frontal sinus and anterior
surface of hard palate
Line B
- Connects anterior wall of
temporal fossa and posterior
edge of hard palate
Line C
- Along planum sphenoidale
Line D
- Along hard palate
Rule:
- Line A & B parallel
- Line C & D parallel
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15. Towne’s View
Excellent view of
- Maxillary sinus:
posterolateral wall
- Zygomatic arch
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16. Key structures
1 = Zygomatic arch
Line A = Posterolateral wall
of maxillary sinus
Rule:
- Smooth, non-disrupted line
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17. Orthopanthogram or Panorex®
Key structures
R = Temporomandibular joint
13 = Mandible, condyle 14 = Mandible, ramus 17 = Mandible, body
18 = Mandible, angle 19 = Mandible, coronoid process 20 = Mandible, symphysis
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18. 8 9
25 24
Counting the teeth on Orthopanthogram or Panorex®
American Dental Association (ADA) system preferred this system because you will speak same ‘language’ with
dentists.
Count from midline and go laterally (some individuals may not have #1, #16, #17, and #32)
Maxillary Arch ADA#1 - 8 (right), #9-16 (left)
Mandibular Arch ADA#32-25 (right), #24-17 (left)
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19. Oblique View of Mandible
Key structures
R = Temporomandibular joint
13 = Mandible, condyle 14 = Mandible, ramus 17 = Mandible, body
18 = Mandible, angle 19 = Mandible, coronoid process 20 = Mandible, symphysis
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20. Biomechanics
 LeFort described areas of
relative strength within the
facial skeleton
 Alveolar process of maxilla
(1)
 Frontal process of maxilla
(2)
 Body of zygoma or malar
eminence (3)
 Line of fracture tends to
avoid these areas
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21. Checklist for Facial
Radiograph/CT
 Facial structures are quite symmetrical
 Do not stop searching when see one abnormality
 If suspect for more than simple nasal fracture, do CT
 Significant (but can be subtle) fractures
 Fracture involves the optic foramen which can cause permanent visual loss if
not treated promptly
 Fracture of the posterior wall of frontal sinus requires neurosurgical
evaluation and may require antibiotics prophylaxis
 Fracture/dislocation of the TMJ usually missed on initial survey. It can cause
significant disability if left untreated
 Look for significant soft tissue injuries
 Globe rupture, hemorrhage
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22.  To be continued in Part 2 and 3
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23.  The information provided in this presentation…
 Is intended to be used as educational purposes only.
 Is designed to assist emergency practitioners in providing
appropriate radiologic care for patients.
 Is flexible and not intended, nor should they be used to
establish a legal standard of care.
 Thanks, MGH Radiology, for cases I’ve seen and things I’ve
learned.
R.K.
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