Oral surgery - Trauma Flashcards
List the 7 bones of the orbit
Maxillary, Facial, Zygomatic, Ethmoid, Lacrimal, Sphenoid, Palatal
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What makes up the upper facial skeleton?
Frontal bone and orbital cavity
What are 3 potential consequences of fracture of the facial skeleton on the brain?
Direct brain injury
secondary injury due to bleeding at fracture site
tear of dura
What structures travel through the Optic canal?
optic nerve
opthalmic artery
What structures travel through the superior orbital fissure?
CNIV, CNIII, CNVI
superior opthalmic vein
What structures travel through the inferior orbital fissure?
Zygomatic br of CNV2
Inferior Opthalmic artery
Why does fracture of mid-facial skeleton affect cranial base? What is the sequelae of this in the case of a mid-face fracture?
Mid facial skeleton articulates with the cranial base
Fracture may cause displacement of cranial base
Signs: Anterior open bite cuasing premature occlusion of posterior teeth
Soft palate pushed down to occlude airway
What is a life threatening sequelae of a mandibular fracture?
Bleeding at FoM causing elevation of tongue and airway occlusion
May cause injury to the cervical spine
List the areas of high impact in the facial skeleton
supraorbital rim
symphysis of mandible
Glabella - frontal
angle of mandible
List the areas of low impact in the facial skeleton
Zygoma
nasal bone
What 4 conditions necessitate emergency medical care after a facial fracture?
- Airway involvement
- Massive haemorrhage
- cervical spine innjury
- orbital fracture with inferior rectis muscle entrapment
By which mechanism can mass haemorrhage occur with facial fracture
A maxillary fracture that involves the pterygoid plexus or internal maxillary artery
After checking airways/haemorrhage, what is the next area to check?
Peri-orbital
What does the peri-orbital exam involve?
Visual acuity
Pupils - size, reaction
Lacterations
Occular muscle movement (CN III,IV,VI)
Orbital palpation - step off, sensation
If the patient has a penetration of the globe what should you do?
Refer to opthalmologist
What is CSF Rhiborrhea?
Cervical Spinal Fluid leakage from nose
What is CSF Rhinorrhea a sign of?
skull base fracture
What are the 3 signs of scull base fracture?
Battle’s sign
Racoon Eyes
CSF Rhinorrhea
What is Battle’s sign?
ecchymosis behind ears
What are racoon eyes?
Bilateral periorbital ecchymosis
Deviation of the mandible on opening is a sign of what?
Condylar fracture
What are the 3 most common facial bones to fracture?
Mandible
Zygomatic
Orbital floor
Which parts of the orbital wall most commonly fracture and why?
Floor or medial wall
Thin bone
What is the hydrolytic theory?
A sudden blow to the orbit will result in sudden expansion within the orbit causing increased pressure, which may cause fracture of orbit.
AKA blow-out fracture
What are the symptoms of an orbital wall fracture?
Enopthalmus
Anaestehsia of infra-orbital area
Diplopia
Infra-orbital step off
subcutaneous emphysema
decreased visual acuity
What is enopthalmus?
orbital content herniates into maxillary sinus causing one eye to appear sunken
What is diplopia?
Double vision when patient looks up
caused by herniation of inferior rectis muscle into fracture
What is the management for orbital floor fracture?
Immediate surgery if inferior rectus muscle entrapment or retrobulbal haemorrhage
OMFD + Opthalmologist referral
nasal decongestants (avoid blowing nose)
CT scan
Retro-bulbal haemorrhage is a risk of what surgery?
orbital floor surgery
Symptoms of retro-bulbal haemorrhage
Proptosis (bulging)
loss of vision
severe pain
non-reactive pupil
muscle palsy
blindness
Describe LeFort I fracture
horizontal fracture invovling low level maxilla, and pterygoid plate
Causes separation of maxilla from mid-face at the base of the nasal cavity
Describe LeFort II fracture
pyrimidal fracture from pterygoid plate, high level maxilla, low level zygomatic bone, infra-orbital foramen
Describe LeFort III fracture
fracture causing craniofacial dislocation from cranial base
zygomatic frontal suture involved
orbital floor
ethmoid sinus and bone
How to you differentiate between LeFort fractures on a CT scan?
I - anterolateral margin of nasal fossa fractured
II - inferior orbital rim fractured
III- zygomatic arch fractured
Repair of a LeFort I fracture involves incision where?
Buccal vestibule
What is used to reduce a LeFort fracture?
miniplates and screws
What are the two types of zygomatic fractures?
Tripod fracture - fractures from 3 suture points
Arch fracture - limited to zygomatic arch
what does ORIF stand for?
Open reduction and internal fixation
Which 4 bones does the zygomatic bone articulate with?
superior : frontal
Medial: maxillary
Posterior: temporal
Lateral: sphenoid
Which bony structure will a zygomatic fracture commonly involve?
orbital floor
zygomatic bone forms part of orbital floor
What important structure do you need to check in a zygomatic fracture?
orbit
check for orbital floor fracture
7
What are the signs of a zygomatic fracture?
asymmetry
depression of zygomatic prominence
step-off
paraesthesia
ecchymosis
subconjunctival haemorrhage
decreased range of mtoion of mandbile (if impinging on coronoid process)
What is a common surgical technique for management of a simple zygomatic fracture?
Gilies incision at hairline
pass instrument along temporal facial to zygomatic bone
elevate fracture portion of zygomatic bone
What are the signs of a mandibular fracture?
Malocclusion
Intra-oral lacerations
sublingual ecchymosis
nerve injury
Why do mandibular fractures often present as multiple fractures, not just one?
U shape of mandible = force transmitted to contralateral side of initial site of impact
What are the 8 classification of mandibular fractures?
Dentoalveolar
condylar
coronoid
ramus
angle
body
parasymphysis
symphysis
Which 3 areas of the mandible are most commonly fractured?
body
angle
condyle
If a mandibular fracture is open, what do you need to do?
prescribe antibiotics
What is IMF
inter-maxillary fixation
In which cases is IMF still used?
comminuted fractures
condylar fractures (surgery impossible here)
