1. Imaging of Facial Trauma
Part 3: Pathology
(Nasal, NOE, Frontal, Orbital Fractures)
Rathachai Kaewlai, MD
www.RadiologyInThai.com
Created: January 2007
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2. Outline
 Facial and mandibular fractures
 Nasal fractures
 Naso-orbital-ethmoidal fractures
 Frontal sinus fractures
 Orbital fractures
 Zygomatic fractures
 Maxillary fractures Next presentation
 Mandibular fractures
 Imaging approach
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3. Nasal Fractures
 Most common fracture of the facial bone
 Etiology: motor vehicle collisions (MVC) most common, followed by assaults
 Relevant anatomy: Nasal pyramid consists of
 Nasal bones
 Inferior part of nasal bones is thinner than superior, more prone to fracture (fx)
 Frontal processes of maxilla
 Nasal septum (superior = perpendicular plate of ethmoid, inferior = vomer,
anterior = quadrangular cartilage)
 Lateral cartilages (upper and lower lateral cartilages)
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4. Nasal Fractures
 Pattern of nasal fractures depend on direction of force
 Frontal direction (frontal blow)
 May cause a simple nasal fx
 Can be severe with flattening of nose, septum
 Can be a part of more complicated fx such as naso-orbital-ethmoidal (NOE) fx
 Lateral direction (lateral blow)
 May cause depression of ipsilateral nasal bone
 May also fracture contralateral nasal bone
 Interlocking of nasal bone and cartilage may occur; requiring open reduction for
adequate cosmetic result
 Inferior direction (blow from below)
 Usually with septum (quadrilateral cartilage, bony septum) fx and dislocation
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5. Nasal Fractures
 Diagnosis:
 Made based on physical examination findings
 Visible bony deformity in displaced fx
 Laceration, ecchymosis, hematoma, mucosal tear and epistaxis in the inner
surface of the nasal cavity strongly suggest fx
 Presence of epistaxis and septal hematoma requires prompt diagnosis
and treatment
 Epistaxis can be life threatening
 Septal hematoma may lead to cartilage necrosis and resultant saddle nose
deformity
 Telecanthus is an indication of more severe injury, further workup
including CT scan is required
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6. Nasal Fractures
 Plain radiography
 Plain film may miss up to nearly half of the patients with nasal fractures
 Nasal bone x-ray:
 Lateral nasal views (soft tissue technique)
 Water’s view
 CT
 CT better depicts fx, especially frontal process of maxilla. Depressed fx of
frontal process of maxilla can lead to facial deformity if left untreated
 CT should be performed if there is more than a simple nasal fracture on x-ray
 Presence of telecanthus should prompt CT workup
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7. Nasal Fractures,
frontal blow
39-yo-man was punched
from the front
Comminuted bilateral nasal
bone fractures (red arrows)
with displaced fragments.
N = nasal bone
M = Frontal process of maxilla
Black arrow = Intact
nasomaxillary suture
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8. Nasal Septum
Fractures
33-yo-man was
punched by a right-
handed person
S = Bony nasal septum
E = Ethmoid sinus
Sp = Sphenoid sinus
 = Orbital emphysema
(in this case from
associated maxillary
sinus fractures)
Fractures of the left frontal process of maxilla (red arrow) and the right nasal bone (green
arrow) are noted. A long arrow indicates a fracture of the bony nasal septum. The fractures
are displaced to the right, indicating the force of impact from the left. The right-handed person
hit the left side of the nose of the victim.
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9. Nasal Septum
Fractures
67-yo-man involved in
a motor vehicle
collision
 S = Bony nasal septum
E = Ethmoid sinus
Blue arrows = Frontal
process of maxilla
 = Orbital emphysema
Deformity of the nose pointing toward the left. There is angulation of the cartilagenous
portion of the nasal septum (red arrows) and blood in the nasal cavity. The patient also had
orbital floor fractures (not shown) with orbital emphysema (star).
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10. Naso-orbital-ethmoidal (NOE)
Fractures
 Etiology:
 Forceful frontal blow to the central aspect of midface.
 Most common from motor vehicle collisions (MVC), followed by
assaults
 NOE fractures involve the central upper face, disrupting the
medial orbit, nose and ethmoid sinuses
 NOE fractures are distinguished from simple nasal fractures by
 Posterior disruption of medial canthal region, ethmoids and
medial orbital walls
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11. Naso-orbital-ethmoidal (NOE)
Fractures
 Relevant anatomy:
 NOE complex consists of nasal, frontal, maxillary, ethmoid,
lacrimal and sphenoid bones
 Superior to NOE complex is anterior cranial fossa
 Lateral to NOE complex is globe
 Deep to NOE complex is optic canal and sphenoid bone
 Center of NOE complex is interorbital space, consisting of
ethmoid sinuses, lacrimal drainage system, nasofrontal ducts
 Therefore, NOE fractures can be related to many significant
surrounding structures
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12. Naso-orbital-ethmoidal (NOE)
Fractures
 Relevant anatomy of Medial canthal tendon
 A crucial soft tissue component of NOE complex
 Medial portion of orbicularis oculi, inserting to the medial orbital wall
 Acts as a suspensory sling for the globe and ensure close apposition of the eyelid
 In NOE fractures, medial canthal tendon pulls the fragment laterally, or (rarely) torn,
causing telecanthus
 Helpful clinical signs to detect traumatic telecanthus
 Intercanthal distance > interpalpebral distance of the eyes
 Intercanthal distance more than one-half of interpupillary distance
 Clinically, the most obvious deformity is loss of nasal projection in profile
and apparent telecanthus
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13. Naso-orbital-ethmoidal (NOE)
Fractures
 Pertinent radiologic information
 Degree of comminution of medial orbital wall, especially in the lacrimal fossa
where medial canthus attaches
 Involvement of nasofrontal ducts require surgical obliteration of frontal sinus
to prevent frontal mucocele
 Extension
 Posterior extension to the optic canal
 Superior extension to the frontal sinus, intracranial structures
 Complications
 Persistent telecanthus
 Injury to lacrimal system
 Nasofrontal duct impingement
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14. NOE Fractures

21-yo-man was assaulted
E = Ethmoid
M = Maxillary sinus
Sp = Sphenoid sinus
 Orbital emphysema
=
Frontal blow to the nasion results
A
in a comminuted fracture involving
the medial walls of both orbits
(green circle), nasal bones (green arrow)
and frontal processes of maxillae
(red arrows) as shown in image A.
Blue arrows indicate the attachment
sites for medial canthal tendons.
Posterior displacement
(depression) of the nasion is noted
in image B.
B
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15. C D
3D images better depict degree of displacement and depression of the NOE fractures. The
fractures also extend to frontal sinuses (F). Comminuted fractures of bilateral nasal bones (N)
and frontal processes of maxillae (M) are shown. Small images on right lower corners represent
normal anatomy in the same projections. Radiologic description should comment on degree of
comminution of medial orbital wall especially in the region of lacrimal fossa, where the
medial canthus attaches and nasofrontal ducts are located.
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16. Frontal Sinus Fractures
 Etiology: motor vehicle accidents (most common), followed by high-impact sport
related injuries
 Clinical
 Gross depression or laceration over supraorbital ridge, glabella or lower forehead (most
common finding on clinical exam)
 Ophthalmologic evaluation may be necessary because up to half of patients have orbital
trauma
 Classification of fractures
 Location: anterior table, posterior table, or both
 Appearance: linear, comminuted, depressed or nondisplaced
 Isolated anterior table fracture is most common
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17. Frontal Sinus Fractures
 Relevant anatomy
 Frontal sinus first appear 6-8yrs, fully pneumatized in adolescence.
 It can be asymmetric and partially pneumatized in up to 20% of
population
 Frontal sinuses drain via either nasofrontal duct located
posteriomedially in the sinus or in conjunction with anterior
ethmoid air cells. The nasofrontal duct, if present and fractured,
can be obstructed - leading to chronic drainage complication
 Frontal sinus is closed to dura, frontal lobe, crista galli and
cribiform plate
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18. Frontal Sinus Fractures
 Indication for surgery
 Fracture potentially injures nasofrontal duct (fx involves base of
frontal sinus, medial to supraorbital notch)
 Depressed anterior table - cosmetic deformity
 Posterior table fx with gross CSF leak, more than one table width
displacement
 Complication
 Early complication: frontal sinusitis (retained FB in sinus) leading
to meningitis, osteomyelitis, orbital abscess or brain abscess
 Late complication: mucocele, mucopyocele, delayed CSF leak
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19. Frontal Sinus Fractures
Two examples. Young
patients who were
assaulted.
Above: Isolated anterior
table fractures (red arrows)
with hemosinus. Intact
posterior table (blue arrow).
This type of depressed
fracture causes cosmetic
deformity
Below: Both anterior and
posterior table fractures (red
and green arrows), which are
nondepressed.
Pneumocephalus (white
arrow)
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20. Frontal Sinus Fractures
Scout CT: Asymmetrical haziness of the left frontal sinus (normal frontal sinus on AP skull
radiograph should have same density to the orbit) indicates hemosinus (red arrow).
Axial CT: Fracture of the posterior wall of the left frontal sinus (green arrows) is confirmed. There is
displacement of the fracture fragments into the sinus. Small pneumocephalus is noted deep to the
fracture. The patient also has anterior wall fracture (not shown). Isolated posterior wall fracture is
rare.
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21. Orbital Fractures
 Plain radiography has a false negative rate of 7-30%
 CT in axial, and coronal planes are essential to determine presence of
fractures and status of intraocular muscles
 Axial: medial, lateral wall fracture, entrapment of medial rectus muscle
 Coronal: floor, roof fracture, entrapment of inferior rectus muscle, fracture
involving nasolacrimal duct
 Both are helpful for fx of optic canal, retro-orbital hematoma
 Two main types
 Blow-out fractures
 Blow-in fractures
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22. Orbital Fractures
 Blowout fractures
 Bone is displaced away from the orbit
 May involve the roof, floor, and medial or lateral walls of the orbit
 Most common = floor
 If orbital rim is intact = ‘pure’ blow-out fracture (classic fx)
 Up to 30% have ocular injury
 Two proposed mechanisms of injury
 Hydraulic mechanism: pressure on eyeball increases intraorbital pressure, then the
orbit ruptures at its weakest point (thin floor)
 Buckling mechanism: blow to orbital rim results in fx of orbital wall
 Clinical: Enophthalmos, diplopia and hypoesthesia (infraorbital nerve distribution) can
be obscured due to swelling
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23. Orbital Fractures
 Blowout fractures
 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
 Abnormal inferior rectus can be
 Entrapped: muscle lies completely beneath or within the defect and appears
round on coronal images
 Hooked: portion of muscle lies within the defect
 Entrapment of inferior rectus in children can be easily missed, since flexible
bone springs back into place like a trap door, looking normal at CT except for
entrapped muscle beneath it
 This requires urgent Rx within 24-72 hours to minimize motility problem
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24. Orbital Blowout Fractures
Middle age patient involved in motor
vehicle accident
Coronal images (in bone and soft
tissue windows) shows the defect (red
arrow) in the floor of the right orbit
with a small hematoma in the right
maxillary sinus (green arrow). Light blue
arrows point to the inferior rectus
muscle, where its inferior portion
(blue arrow) is hooked to the defect.
O = Optic nerve
= Facial soft tissue edema
Clinical ophthalmologic exam
is required to confirm or rule
out evidence of intraocular
muscle entrapment.
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25. Orbital Blowout Fractures
81-year-old woman fell from stairs
Intraorbital fat herniation (green arrow) through the defect in the floor of the left orbit. The
inferior rectus (blue arrow) is far from the site of fracture. 3D image shows intact orbital rim
(red arrows) indicative of ‘pure’ blow-out fracture.
O = Optic nerve, H = Hemosinus
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26. Orbital Fractures
 Blow-in fractures
 Bone is displaced into the orbit, intraorbital volume is decreased
 May involve the roof, floor, and medial or lateral walls of the orbit
 If orbital rim is intact = ‘pure’ blow-in fractures
 Clinical
 Exophthalmos (due to decreased orbital volume)
 Decreased visual acuity (eyeball trauma, optic neuropathy, fracture of
optic canal)
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27. Orbital Blow-in Fractures
80-year-old man fell onto his face.
Fractures of the floor of the left orbit (red arrow) displace superiorly into the orbit.
The medial rectus muscle (blue arrows) is pushed upward by the fracture fragment.
Intraorbital volume is further decreased by retroorbital hematoma (blue star).
H = Hemosinus
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28. Orbital Fractures
 Orbital floor fractures
 Most common portion of orbit to sustain a fracture
 Usually associated with other complex midface fractures (ZMC, LeFort II
and LeFort III fractures)
 Can be linear, comminuted, or segmental
 Herniation of intraorbital contents
 Best seen in coronal projection
 What determines chance of herniation, entrapment?
 Size of fragment, degree of depression
 Inferior rectus muscle can be free, hooked, or entrapped
 Indications for surgery
 Involvement > 50% of the floor, combined floor and medial wall fx with soft
tissue herniation, significant enophthalmos (> 2mm), significant diplopia
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29. Orbital Fractures
 Medial wall fractures
 Usually associated with other complex midface fractures
 Risk of medial rectus herniation (either hooked or entrapped) - relatively rare
 Orbital roof fractures
 Risk of brain herniation into the orbit (better seen with coronal reformatted CT
or MRI)
 Orbital apex fractures
 Emergent surgical cases if there is radiologic and clinical evidence of optic
nerve impingement
 May be associated with blindness
 May be associated with carotid artery injury (cavernous portion)
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30. Orbital Fractures
 Soft tissue injuries of the orbit
 Eyeball rupture
 Usually there is extrusion of vitreous (normal intraocular pressure is higher
than intraorbital pressure) - leading to CT signs ‘flat tire’ sign and ‘deepening’ of
anterior chamber
 Lens injury: subluxation, dislocation, traumatic cataract
 Zonular fibers hold lens in place to ciliary muscle. If torn (partial or complete),
subluxation or dislocation occurs
 Traumatic cataract (acute lens edema): affected lens has density 30HU less than
normal side
 Intraorbital hemorrhage
 Intraorbital foreign body
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31. Globe Rupture and Vitreous Hemorrhage
21-year-old man was assaulted.
Right globe rupture is evident by flattening of the posterior wall of the globe “flat tire
sign” (red arrow) and narrowing of the space between cornea and lens “deepening of
anterior chamber” (red line). = Vitreous hemorrhage
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32. Hemorrhage: Preseptal, Vitreous and Choroidal
Preseptal hemorrhage = bleeding in the space anterior to the globe (green arrows, line)
Vitreous hemorrhage = bleeding in the posterior chamber of the globe (red star), usually making ‘obtuse’
angle with the surrounding vitreous
Choroidal hemorrhage = bleeding in the choroid (white stars) along the wall of the globe
Blue arrows represent subcutaneous edema/hemorrhage.
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33. Traumatic Lens Dislocation
60-year-old man was found down.
Traumatic left lens dislocation (red arrow) is noted. Dislocation occurs due to tear of zonular
fibers normally surrounding the lens. Blue arrows point to normal lens with presumed
locations of zonular fiber attachment. The patient also has diffuse subarachnoid hemorrhage
(red stars) and multiple facial fractures.
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34.  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.
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