Imaging in facial trauma

1. IMAGING IN FACIAL
TRAUMA

2. CASE PRESENTATION

3. OUTLINE
Epidemiology
Initial management
Imaging: CT vs radiography
Normal Anatomy
Types of fractures
Imaging approach

4. EPIDEMOLOGY
Etiology:
 Motor vehicle collision is most common cause
 Followed by fights, assault
 Less common: fall, sports activities, industrial
accidents, gunshot wounds.
Soft tissue injury commoner than fracture.

5. Most common fracture is nasal bone fracture.
Most common fracture in admitted patients is
zygomatic maxillary complex fracture – 40%;
followed by Le fort.

6. In children facial fractures are less common –
10%
Most common cause – fall
Fractures more frequent in children than
adults:
 Mandibular condyle
 Orbital roof

7. INITIAL MANAGEMENT
Secure airway, breathing and circulation.
Evaluation of more serious injuries of head,
chest and abdomen.

8. Significance of facial trauma in initial
management:
 Facial fractures may impinge on oral or nasal
airways.
 Nasal bleeding may be life threatening
 Mandible fracture – loss of support of tongue
leading to airway compromise.
 May compromise vision.

9. IMAGING
When to do imaging of the face?
 After the patient is stabilized.
 Head CT should be critically evaluated for
emergent findings: some facial injuries can
compromise vision if not immediately recognized.
CT is the modality of choice*.

10. Role of imaging
Identify fractures, displaced/rotated
fragments, stable bone for use in surgical
repair.
Identify soft tissue injuries.

11. NORMAL ANATOMY
Face is the region from
supraorbital rib to
maxillary alveolar
processes.
Mandible including
TMJ is included
separate from the face.

14. COMPUTED TOMOGRAPHY
Preferred modality of choice as it is more
sensitive for fracture detection, identifying soft
tissue injury especially globe.
Easier to perform than plain film radiographs.
Can miss subtle tooth fracture --- CT
orthopanthogram.

20. 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
simple nasal bone fracture, CT is indicated.
Proper positioning is critical

21. POINTS TO REMEMBER
Plain film is a 2D image of a 3D object,
overlapping structure significantly obscure
anatomical details.
Symmetry is usual and asymmetry is a suspect.
Multiplicity; fractures of facial bones are
usually multiple; don’t stop looking for others
if see one.

22. FACIAL SERIES
 Water’s view
 Caldwell view
 Towne’s view
 Lateral view
 Base of skull
MANDIBLE VIEWS
 Oblique view;
towne’s view
 Orthopanthogram
Additional lateral view for nasal bone (nasal
technique)

29. Oblique view of
mandible

30. TYPES OF FRACTURE
Nasal fractures
Naso-orbital ethmoid
Frontal sinus fracture
Orbital fracture
Zygomatic fracture
Maxillary fracture
Le fort fracture

31. NASAL FRACTURE
Most common fracture of facial bone.
Motor vehicle collision is the most common
cause followed by assault.
Pattern of nasal fracture depends upon
direction of force.

32. Plain radiography can miss up to nearly half of
nasal fractures.
CT better depicts nasal fracture especially
frontal process of maxilla.
Ct should be performed if there is more than a
simple nasal fracture on plain x ray.
Presence of tele canthus indicates severe injury
and should prompt CT work up.

33. NASAL PYRAMID consists of:
 Nasal bones
 Frontal processes of maxilla
 Nasal septum
 Lateral cartilages (upper and lower)

36. NASO-ORBITAL ETHMOIDAL
FRACTURE
Caused by forceful frontal blow to the mid face.
Involves the central upper face, disrupting the
medial orbit, nose and ethmoid sinuses.
Distinguished from simple nasal fracture by
posterior disruption of medial canthal region,
ethmoids and medial orbital wall.

37. The naso-orbito-ethmoid complex is composed of a confluence of several bones: (1)
frontal bone, (2) nasal bone, (3) maxillary bone, (4) lacrimal bone, (5) ethmoid bone,
and (6) sphenoid bone.

39. FRONTAL SINUS FRACTURE
Clinically causes gross depression over superior
orbital ridge, glabella or lower forehead.
Ophthalmological examination may be needed.
Can be classified as:
 Anterior table fracture (isolated – most common)
 Posterior table fracture
 Both

42. ORBITAL FRACTURE
Plain radiograph has a false negative rate of
7-30%.
Ct in axial and coronal planes are essential to
determine the presence of fracture and
status of intraocular muscles.
Two main types; blow in and blow out
fracture.

43. BLOW OUT FRACTURE
Bone is displaced away from the orbit.
Most common = floor
Up to 30% have ocular injury

44. Image interpretation special attention to:
Appearance of inferior rectus muscle on
coronal images.
 Normal = oval shape
 Abnormal = round shape
Location of inferior rectus muscle
 Abnormal = located below the expected
level of orbital floor.

45. Abnormal inferior rectus can be:
 Entrapped: muscle lie completely beneath
or within the defect and appear round on
coronal images.
 Hooked: portion of muscle lies within
defect.

48. BLOW IN FRACTURE
Bone is displaced into the orbit; orbital
volume is decreased.
Clinically exophthalmos and decreased visual
acuity.

50. ZYGOMATIC FRACTURE
Two types:
 Zygomatic complex fracture
 Isolated zygomatic arch fracture

51. ZYGOMATIC COMPLEX
FRACTURE
Involves three component:
 Orbital process of zygoma
 Inferior rim of orbit
 Zygomatic arch
Main fragment is zygoma which is
separated from its three areas of
attachment.

52. Fracture almost invariably traverse the
infraorbital nerve foramen – impaired
sensation of cheek and upper portion of the
upper lip.
Image interpretation should pay additional
attention to:
 Alignment of zygoma
 Lateral orbital wall alignment

54. ZYGOMATIC ARCH FRACTURE
Direct blow by small object
Three fracture line:
 One at each end and third in the center with
depression of fracture fragment.
Limited motion of mandible:
 Fracture impinges on coronoid process
 Masseter arises from zygomatic arch

55. MAXILLARY FRACTURE
Maxillary sagittal fracture
Palate fracture
Alveolar process fracture
Le Fort fracture

56. MAXILLARY SAGITTAL FRACTURE
Fracture of maxilla in sagittal plane,
involving anterolateral wall of maxillary
sinus.
Plain film --- opacified maxillary sinus

58. ALVEOLAR PROCESS FRACTURE
Mal alignment and
displacement of
teeth.

59. LE FORT FRACTURE
Most severe fracture seen in face and
associated with high energy trauma.
In each type there is partial or complete
separation of maxilla from facial skeleton.
All LeFort fractures must extend through
posterior face and transects the pterygoid
process.

60. LEFORT TYPE I
Trans maxillary fracture
Transverse fracture of inferior maxilla,
involving maxillary sinus (except superior
walls), lateral margin of nasal fossa, nasal
septum and pterygoid plates

61. Opacified bilateral maxillary sinuses
Transverse fracture through inferior
maxilla above hard palate

63. LEFORT TYPE II
Pyramidal shape maxillary fracture,
involving maxillary sinuses (anterolateral
wall),inferior orbital rim, orbital floor and
nasofrontal suture.

64. Opacified bilaterally maxillary sinuses and
orbital emphysema.
Fracture of anterior/lateral walls of maxillary
sinus, inferior orbital rims/floor and
disruption of nasofrontal suture.

66. LEFORT III FRACTURE
Also known as craniofacial disjunction.
Separates calvarium from facial bones.
Plain film underestimates degree of injury
due to severe soft tissue swelling.
CT is recommended.

67. Zygoma separated from sphenoid at
zygomatico-sphenoid suture.
Nasal bone and medial orbital wall separated
from frontal bone at nasofrontal suture.

70. CONCLUSION
 CT is more accurate and easy to perform in case of
facial trauma.
 Facial structures are quite symmetrical; look for
asymmetry.
 When suspect more than simple nasal fracture; do
CT.
 Soft tissue injuries should be ruled out; look for
subtle fractures which can result in significant
damage.