The document is an introduction to a series on imaging facial trauma. It outlines the topics to be covered, including the epidemiology of facial fractures, normal anatomy visualized on CT imaging, and the role of imaging in evaluating facial trauma. CT is described as the preferred imaging modality as it can accurately evaluate both bony and soft tissue injuries with low radiation dose.

1. Imaging of Facial Trauma
Part 1: Introduction
Rathachai Kaewlai, MD
Specialized in Body Imaging and Emergency Radiology
rathachai@gmail.com
January 2007
The author is willing to receive any input, comments and corrections,
Please do not hesitate to contact at the email address provided above. 1
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

2. Outline
• Facial fracture epidemiology • Types of facial fracture
• Initial management – Nasal bone fracture
• Imaging: CT versus – Naso­orbital­ethmoid
radiography fracture
– Frontal sinus fracture
• Normal anatomy
– Orbital fracture
– 3D
– Zygomatic fracture
– CT (axial, coronal and
sagittal planes) – Maxillary fracture
– Radiography – Mandibular fracture
• Biomechanics • Imaging approach
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

3. Epidemiology
• Etiology (USA)
– Motor vehicle collision (MVC) most common cause
– Followed by fights, assaults
– Less common: fall, sports activities, industrial accidents, gun shot
wounds
• Soft tissue injury is more common than fracture
• Co­existence of other injury
– 3­14% of patients with facial fracture have skull fractures
– 1­4% of patients with facial fracture have cervical spine fractures
– 20% of patients with cervical spine fractures have facial injury (half
soft tissue injuries, half fractures)
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

4. Epidemiology
• Distribution of fracture
– Vary with mechanism of injury
– In general, most common facial fracture is nasal bone fracture
– Most common fracture in admitted patients is zygomatic complex
(ZMC) fracture at 40%, followed by complex fractures such as
LeFort fracture
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

5. Epidemiology
• Facial fracture in children
– Less common (< 10% of all facial fractures occur in children)
– Less severe than adults
– Most common etiology is fall
– Reason: midface is less prominent, sinuses are less pneumatized,
more elasticity of bones
– Fractures that are more frequent in children than in adults
• Mandibular condyle
• Orbital roof
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

6. ABC of Trauma
• Initial patient management is to secure airway (A), breathing
(B) and circulation (C)
• Evaluation of more serious injuries of the head, chest and
abdomen
• Avoid blind insertion of endotracheal tube and nasogastric tube
• Significance of facial trauma for the initial management
– Facial fractures may impinge on oral or nasal airway
– Nasal bleeding may be life threatening
– Mandible fractures may cause loss of support for tongue, then
airway compromise
– Facial fractures may compromise vision
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

7. When to Do Imaging of the Face?
• When the patient is stabilized
– Clinically (Airway, Breathing, Circulation ­ stable),
• Initial goal is to preserve life ­ then later restore the form and function of
the face
• Cervical spine clearance
– Radiographically
• For cervical spine clearance
• Head CT should be thoroughly evaluated in a multitrauma
patients
– Search for critical, emergent finding: some facial injuries may
compromise vision if not immediately recognized
– In stable patient, face CT can be performed with little additional
time when the patient is already in the scanner
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

8. What Imaging to Do?
• Role of imaging
– Identify fractures, fragment displacement and rotation, stable bone
for use in surgical repair
– Identify soft tissue injuries
• CT is the imaging modality of choice because
– High accuracy for evaluation of both bony and soft tissue injuries
– Can be cost­saving screening exam when compared to multiple
views of plain film radiography*
– Radiation dose is far below the threshold for cataract formation
*Turner BG et al. AJR Am J Roentgenol 2004;183:751­754
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

9. Normal Anatomy
• Face
– Face (midface) is the region
from supraorbital rims to and
including maxillary alveolar
process FACE
– Mandible, including the
temporomandibular joints
(TMJ), considered separate
from the face
– This lecture series will
include both parts (face and
mandible)
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

10. 3D CT
Anterior View
Major structures
are labeled in the
picture.
Nasofrontal suture
Zygomatico­frontal
suture
Zygomatico­
temporal suture
SOF = Superior orbital
fissure
IOF = Inferior orbital
fissure
Orbital ‘rim’ is different
from the ‘wall’
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

11. 3D CT
Left Lateral View
Nasofrontal suture
Zygomatico­frontal suture
Zygomatico­temporal suture
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

12. 3D CT
Base View
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

13. Computed Tomography (CT)
• Preferred modality for imaging of the face
– More sensitive for fracture detection
– Show significant soft tissue injury, especially the globe
– Easier to perform, quicker than complete views of plain film
radiographs
– Presurgical planning for complex injuries
– Low radiation dose
– ? Lower cost ?
• Disadvantage of CT
– CT can miss subtle tooth fracture along the axial plane,
additional orthopanthogram (Panorex ®) may be helpful to detect
tooth fracture
13
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

14. Computed Tomography (CT)
• CT protocol
– Axial scanning from above the frontal sinus down to below hard
palate (face), and can be scanned further to include the mandible, if
there is a clinical suspicion for fracture of mandible
– For helical (spiral) scanner, axial images can be reconstructed to
coronal and sagittal planes without the need for direct coronal
scanning
– Viewing in both bone and soft tissue windows, in 3 planes
(axial, coronal and sagittal)
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

15. • Posterior wall of
frontal sinus fracture
may co­exist with
brain injury
• Presence of
pneumocephalus will
signify dural tear
related with the fracture
• Inferior part of frontal
sinus constitute the
medial orbital wall
Key structures
A = Frontal sinus, anterior wall
B = Frontal sinus, posterior wall
*Note: The right frontal sinus is not pneumatized in this case.
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

16. 
Key structures
D = Orbit, medial wall
E = Orbit, lateral wall
F = Suture between
sphenoid and
zygomatic bones
 = Nasomaxillary
suture
1 = Globe
2 = Ethmoid sinus
3 = Sphenoid sinus
4 = Nasal bone
5 = Maxilla, frontal
process
• Do not confuse the suture between nasal bone and frontal process of 6 = Orbit, lateral rim
maxilla for a fracture 7 = Sphenoid bone
• Look for a piece of fracture in the optic foramen, it is the true 8 = Optic foramen
emergency of facial fracture 16
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

17. Key structures
F = Groove for
infraorbital nerve
G = Maxillary sinus,
posterolateral wall
5 = Maxilla, frontal
process
9 = Maxillary sinus
10 = Zygomatic arch
11 = Pterygoid bone
12 = Nasolacrimal duct
13 = Mandible, condyle
Clear maxillary
sinuses can almost
rules out certain
fractures such as
ZMC, LeFort, blowout
fractures
17
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

18. Key structures
H = Maxillary sinus,
anterior wall
I = Maxillary sinus,
medial wall
J = Medial pterygoid
plate
K = Lateral pterygoid
plate
9 = Maxillary sinus
14 = Mandible, ramus
Fracture of the
pterygoid plates may
represent LeFort
fracture
18
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

19. Key structures
J = Medial pterygoid
plate
K = Lateral pterygoid
plate
L = Maxilla, spine
14 = Mandible, ramus
15 = Maxilla bone/ hard
palate
Lucency in midline of
the maxilla is a
normal finding seen
occasionally
19
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

20. Coronal
Reformatted Images
Key structures
L = Maxilla, spine
 = Nasomaxillary suture
4 = Nasal bone
5 = Maxilla, frontal process
• Do not confuse nasomaxillary suture for a fracture
• Remind yourself that CT can miss subtle tooth
fracture, although with the coronal and sagittal
reformation. Obtain orthopanthogram or dedicated
tooth film when in doubt
20
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

21. Key structures
D = Orbit, medial wall
M = Nasal septum
5 = Maxilla, frontal process
15 = Maxilla bone/ hard palate
16 = Frontal sinus
17 = Mandible, body
21
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

22. Key structures
M = Nasal septum
N = Ethmoid bone,
perpendicular plate
O = Orbit, roof
P = Orbit, floor
Q = Maxillary sinus,
posterolateral wall
= Zygomatico­frontal
suture
1 = Globe
2 = Ethmoid sinus
6 = Orbit, lateral rim
9 = Maxillary sinus
22
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

23. Key structures
J = Medial pterygoid
plate
K = Lateral pterygoid
plate
N = Ethmoid,
perpendicular plate
3 = Sphenoid sinus
10 = Zygomatic arch
14 = Mandible, ramus
18 = Mandible, angle
23
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

24. Sagittal Reformatted Images
Key structures
R = Temporomandibular joint (TMJ)
13 = Mandible, condyle
14 = Mandible, ramus
19 = Mandible, coronoid process
20 = Mastoid air cells
If patient opens his/her mouth during
the scan, there is a normal anterior
gliding of the mandibular condyle
relative to the glenoid fossa. That can
look like subluxation of the TMJ
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

25. Key structures
P = Orbit, floor
7 = Pterygoid bone
9 = Maxillary sinus
15 = Maxilla bone /hard
palate
• Orbital blowout fracture
is best seen in sagittal
and coronal images
• Facial CT is not
completed without image
reconstruction
25
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

26. Key structures
3 = Sphenoid sinus
4 = Nasal bone
15 = Maxilla bone/ hard
palate
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

27. CT Orthopanthogram
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

28. Axial Coronal
Sagittal
Right Orbit, soft tissue window
Key structures:
ON = Optic nerve MR = Medial rectus
LR = Lateral rectus IOL = Intra­ocular lens
• Globe contour should be smooth
• Clean (dark) retro­bulbar fat
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

29. 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 x­ray
beam is critical for evaluation because facial skeletal
anatomy is complex
29
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

30. 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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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

31. Plain Film Radiography
• Facial series
– Water’s view (PA view with cephalad angulation)
– Caldwell view (PA view)
– Towne’s view
– Lateral view
– Base view
• Additional view
– Lateral view of the nasal bone (nasal technique)
• Mandible
– Oblique view, Towne’s view
– Orthopanthogram
Note: The lecture series will be focused on CT scan 31
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

32. 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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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

33. 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, non­disrupted,
same contour on both sides
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

34. Line A
­ Begins at inner surface of
zygomatico­frontal 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
­Begins at lateral and
inferior margin of maxilla
and extends along lateral
wall of maxillary sinus and
inferior surface of zygomatic
arch
­ Ends at glenoid fossa
34
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

35. 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) Zygomatico­maxillary
complex (ZMC)
3) LeFort (unilateral or
bilateral)
35
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

36. 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)
36
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

37. 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 non­disrupted
orbital walls
37
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

38. 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
38
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

39. 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
39
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

40. 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
40
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

41. Towne’s View
Excellent view of
­ Maxillary sinus:
posterolateral wall
­ Zygomatic arch
41
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

42. Key structures
1 = Zygomatic arch
Line A = Posterolateral wall
of maxillary sinus
Rule:
­ Smooth, non­disrupted line
42
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

43. 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
43
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

44. 8 9
25 24
Counting the teeth on Orthopanthogram or Panorex®
American Dental Association (ADA) system preferred 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), #9­16 (left)
Mandibular Arch ADA#32­25 (right), #24­17 (left)
44
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

45. 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
45
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

46. 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
46
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

47. 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
47
Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD

48. • The information provided in this presentation…
– Does not represent the official statements or views of the Thai
Association of Emergency Medicine.
– 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.
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Emergency Radiology: Imaging of Facial Trauma Rathachai Kaewlai, MD