Facial Bones Pathology Flashcards
What is a key sign of pathology/# to look out for?
fluid levels and soft tissue masses in the sinuses
What are the direct radiographic signs? - 5 points
linear lucencies corticol break widened suture bone fragments overlapping asymmetry of face
what are the indirect radiographic signs? - 3 points
soft tissue swelling
peri-orbital / intracranial air
fluid in paranasal sinus (usually maxillary)
What are Dolan’s lines?
what do they follow?
why are they useful?
used in assessing facial bones for injury
follow the margins of the zygoma and the orbital margins of the zygoma and maxilla
useful because the zygoma = frequent site of #
what should be looked out for in zygomatic #s?
what can help reveal an abnormal contour of the zygomatic arch?
look for the ‘elephant trunk’ appearance of the zygomatic arch
by comparing symptomatic side with a symptomatic side
what are McGrigor’s lines?
a system for inspecting the occipito-mental view - 3 lines principle used to identify facial bone #s
why should we check above and below the lines indicated?
to see if there is evidence of a fluid level/soft tissue opacity which may indicate a #
Describe line 1 of McGrigor’s lines
What to look for - 3 points
s / widening of fronto-zygomatic suture / fluid level in frontal sinus
trace a line through the suture between the frontal bone and the zygomatic bone at the lateral margin of the orbit, follow across the forehead assessing the superior orbital margin and the frontal sinus, continue on other side of radiograph following the same landmarks
Describe line 2 of McGrigor’s lines
What to look for - 2 points
trace a line upwards along the superior border of zygomatic arch crossing the body of zygoma, continue onto inferior margin of the orbit and over the bridge of the nose, follow same landmarks onto the other side of the face #s of zygomatic arch, # through inferior rim of orbit
Describe line 3 of McGrigor’s lines
What to look for - 2 points
trace a line along the inferior margin of the zygomatic arch, down the lateral wall of maxillary antrum, continue along the inferior margin of the antrum, across the maxilla, including the roots of the upper teeth #s of zygoma and lateral aspect of the maxillary antrum, fluid levels
what are advantages of the OM30 view - 3 points
much more ‘tangenital’ and appears ‘distorted’
zygomatic # evident on right side of pt
orbital floor is seen in more detail from inferior perspective
Describe the Tripod #
has 4 visible components
1 - widening of the zygomatic-frontal suture
2 - orbital floor #
3 - # of lateral wall of maxillary antrum
4 - zygomatic arch #
What are the causes of a tripod #? - 4 points
what are the symptoms? - 3 points
personal altercations, falls, MVAs and sport injuries
Trismus (reduced jaw mobility) may results from compression of zygomatic arch on temporalis muscle and coronoid process, orbital floor disruption can result in subcutaneous emphysema, infraorbital nerve injury may result in anaesthesia or paresthesis of the cheek/nose/upper lip/lower eyelid
what is the treatment for a tripod #?
non-displaced #s may be managed without surgery but need ophthalmologic exam, analgesia follow up
complex #s need to be assessed several days after injury when much of the tissue oedema has resolved - aim to gain stable, accurate reduction while minimising external scars and functional deformity
surgery can involve plating the fronto-zygomatic suture line or in more complex cases using 3 point fixation
what is the management for a tripod #?
observation, antibiotics possibly steroid administration to reduce oedema and ophthalmic examinations to check diplopia (upward and far lateral gaze) - caused by muscle entrapment/nerve damage/muscle contusion - may be ongoing evidence of facial asymmetry and paresthesias
what is a blowout #?
pressure anteriorly results in # of orbital wall = Buckling theory - transmission of a direct orbital rim force causes a #
what are the causes of blowout #? - 5 points
result of MVAs, industrial accidents, sports-related facial trauma and assaults, in adult female population NAI in form of domestic violence
what can blowout #s cause? - 2 points
what can blowout #s involve?
what is the trapdoor variant of the blowout #?
ocular motility disturbance and globe malpositioning
infraorbital nerve damage
infraorbital soft tissue (muscle/fat) may become entrapped within # as the elastic bones snap back into place resulting in potential severe restrictive optical issues
what can be a sign of a blowout #in paediatrics?
Why do we intervene in a blow out #?
a relative lack of external periocular signs of trauma - white-eyed blow out #
to prevent vision loss and to minimise late problems such as persistent diplopia and disfiguring globe malpositioning
what are the symptoms of a blowout #? - 5 points
diplopia - common, muscle restriction associated with peri-muscular tissue entrapment at #, severe epistaxis, CSP leakage and lacrimal drainage problems, orbital roof #s can be associated with intracranial injury
TEARDROP SIGN
what is the treatment for a blowout #? - 6 points
oral antibiotics likely to be administered as #s cause laceration of the sinus mucosa, analgesia and antiemetrics may be required, use of oral steroids to decrease soft tissue oedema
surgical repair involves reduction and rigid fixation with replacement of lost/comminuted bone, possible lens implants and reconstruction of orbital wall with cancellous bone grafts
what is the management for a blowout #?
diplopia, muscle and nerve damage should be monitored for at least 6 months
what is an orbital blowout # usually accompanied by?
fluid level in the maxillary antrum
describe orbital emphysema
where does the air come from?
air has leaked into the orbit and is sometimes referred to as the ‘eyebrow’ sign, air rises into the most superior aspect of the orbit, almost always in the context of a facial # in a linear fashion, giving the appearance of an eyebrow
comes from either the maxillary or ethmoid sinus after a #
