Chapter 68- Facial Trauma Flashcards
best time to reduce nasal fx
immediately after (1-2 hr) OR 5-10d later once swelling has subsided
how edentulous mandible affects repair
no cross-sectional stability
too weak to load share site w/ small bone plate
needs load-bearing reconstruction
color of vision lost earliest with orbital injury
red
Feature of all LeFort fxs
traverse pterygomaxillary fissure
interrupt pterygoid plates, mobile palate
two most common mandible fx sites
angle
condyle
Aspects of PE important with facial trauma
ABC Cerv spine/brain CN Eye Ear (hearing, hemotymp, fx) Skull/midface/mandible Throat: occlusion, TMJ fxn, bleed, hematoma, airway, speech, swallow
which areas of h/n difficult to evaluate w/o sagittal/coronal recons?
orbital floor
mandibular condyle
frontal sinus outflow tract
Radiographic signs of fx
Non-anatomic linear lucency, cortical defect, suture diastasis, overlapping bone fragment, facial asymm
soft tissue swell, periorbital/IC air, fluid in sinus (indirect)
High vs low impact forces
Low are <50g (<50 times force of gravity)
g’s that different facial bones can withstand
nasal- 30 zygoma- 50 mandible angle- 70 frontal-glabella- 80 midline maxilla/mandible- 100 supraorbital rim- 200
Indications for surgery for A/P table fxs of frontal sinus
Ant: bony displacement causing deformity, FSOT impairment
Post: displace post table >1 table width, dural injury, CSF rhinorrhea, FSOT impairment, severely comminuted
Approaches to frontal sinus
trephination, elevate anterior wall frontoethmoidectomy using lynch incision ORIF through laceration or coronal flap obliteration cranialization
How to avoid vessel/nerve injury when raising coronal flap
avoid CN VII frontal branch injury by incising superficial layer of deep temporal fascia at temporal line of fusion, so elevation can be deep to this layer
osteotome to inferior lip of supraorbital/trochlear nerve foramen to allow nerve to move inferiorly
How to treat nasal fx that occurred 10d ago
may not be amenable to closed reduction
may need complete healing (3-6mo) then septorhinoplasty
3 types of medial canthal tendon injuries
I- single noncomminuted central fragment, MCT attach
2- central fragment comminuted
3- MCT detached
Types 2/3 need transnasal wiring
where orbital contents leak into sinuses in blowout fracture
floor (0.5mm)
less often the lamina (0.25mm)
When to perform surgery with blowout fx of orbital floor
enophthalmos >2mm
double vision primary or inferior gaze
EOM entrap (forced duction)
>50% floor on CT
white eye blowout fracture
greenstick (child)
contents leak out floor, then bone closes, inferior rectus trapped/ischemic
white sclera, usually with nausea
Surgical approaches to orbit
Floor: infraorb, subciliary, transconj (pre/post septal)
Med: transcaruncular, endoscopic, lynch (external ethmoidectomy)
Lat: infrabrow, upper lid skin crease (bleph), extended lower lid transconj with lateral canthotomy
Roof: lynch, transbrow, coronal
risks of lynch incision
between medial canthus and bridge
skin scar, disinsert medial canthal tendon, damage lacrimal sac, diplopia from trauma to trochlea of sup oblique, scar
How does transcaruncular approach compare to lynch for medial orbit access
rapid, less dabmage to skin/muscle layers, better cosmesis, less manipulation of lacrimal sac, MCT
absolute indications for lateral canthotomy
retrobulbar hemorrhageg acute loss of visual acuity, increased IOP, proptosis
If unconscious: IOP >40 (NL is 10-21)
Optic nerve injury manifestations
First: lose red color vision
Later: other colors, decreased central vision, APD, visual field defect
Tx: steroids (high dose) or surgical decomp
traction test
with NOE fx, pull laterally on lower eyelid to see if MCT disrupted
4 fractures of ZMC fracture
ZM suture (infraorb rim)
Arch
ZF (lateral rim)
Sphenozygomatic suture
Vertical midface buttresses
resist forces of mastication
nasomaxillary (medial) from nasomaxillary to frontal bone
zygomaticomaxillary (lat)
pterygomaxillary (post)
Horizontal buttresses
supports between verticals palate central facial buttress (malar to malar, interrupted by piriform aperture) frontal bar zygomatic arch A/P
LeFort I-II-III
I: above maxillary alveolus…float palate
II: nasion - lacrimal bone - inferior orb floor/rim - ant wall max sinus
III: zyg bone, NF, FM sutures, orbit.
Greater wing of sphenoid prevents fx from continuing to optic canal
Thirds of Face
Upper: frontal bone/sinus/lobe
Middle: nasal, NOE, orbit, ZMC, maxillary
Lower: mandible, TMJ
Order of repairs with panfacial
Stable to unstable
1: nasal and zygomatic bones to cranial bone
2: mandible to maxilla
3: maxilla to nasal and zygomatic bones and cranium
what often occurs with a parasymphyseal fx?
condyle fx
bite deformity caused by condylar fx
open
treatment of condylar fxs
only ORIF if subcondylar
if head/neck, then non-surgical
tough to ORIF b/c near CN VII, bone cannot support hardware, unfavorable due to lateral pterygoid
Indications for ORIF of condyle fx
Absolute: displace into MCF/EAC, cannot get adequate occlusion, lateral extracapsular dislocation, contaminated open joint wound
Relative: Bilateral in edentulous patient if splints unavailable, splinting not recommended, bilateral with comminuted facial fxs, bilateral with: retrognathia/prognathia, open bite and periodontal problems, loss of multiple teeth, unstable occlusion, one of the condylar fx with unstable fracture base
Why is functional therapy important with condylar fxs?
avoid ankylosis of TMJ
Start right after MMF removed, or right away if no MMF
why angle is easy to fx
weakened by 3rd molar
thinner cross-sectional area
Which mm pull on angle fx?
masseter, medial pterygoid (unfavorable)
Which plate goes on sup border with angle fxs
tension plate on sup border (reduce separation with chewing)
may not need plate at inf border of angle fx b/c compresses with chewing to keep fx reduced
Occlusion classes
I- MBC maxillary 1st molar contacts BG mandibular
2 retrognathia- posterior mandible
3- prognathia, anterior mandible
Closed vs open mandible fxs
Closed: non-displaced, favorable, pediatric, grossly comminuted, coronoid, adult condyle (some)
Arch Bar/Ivy loop/Risdon wire/splints/dentures
Open: displaced unfavorable, atrophic edentulous, complex facial, condylar if cannot be treated by closed
Edentulous mandible considerations: closed and open
Smaller, more fragile, less osteogenesis/blood supply, depend on periosteum for nourishment
Closed: gunning splints, dentures, external pin fixation
Open: heavy load bearing plates with bicortical scres (bone too weak to load share)
Pediatric mandible fx considerations
Conical teeth, short roots, not amenable to MMF
6 and younger: closed
12 and older – should have permanent teeth, can do ORIF with mini plate…avoid condylar injury b/c major elongation center
