ORAL SURG zygomatic fractures Flashcards

1
Q

what are the 2 categories of tx goals for zygomatic fractures?

A
  1. restore facial projection/ symmetry
  2. restore orbital volume/ globe position/ shape palpebral fissure
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2
Q

what factors affect treatment of zygomatic fractures?

A
  1. timing
  2. type
  3. mechanism
  4. presentation
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3
Q

what are the 3 categories of treatment timing for zygomatic fractures?

A
  1. immediate
  2. early
  3. delayed
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4
Q

when do you ideally want to treat a zygoma fracture?

A

early (few days-1 week) - this allows for reduction of swelling to understand anatomy better and surgical access

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5
Q

what are the 2 mechanisms (fracture types) of zygomatic fractures?

A

low energy - minimal/ no comminution
high energy - comminution at segment and fracture lines

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6
Q

what are the 3 overall zygomatic fracture types?

A
  1. non-displaced
  2. displaced, minimally comminuted
  3. complex and comminuted
  4. isolated zygomatic arch fractures
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7
Q

what landmark is the most reliable indicator of proper reduction and orientation of zygomatic fractures?

A

zygomaticosphenoidal suture

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8
Q

what type of treatment is usually given for zygomatic fractures?

A

open reduction and internal fixation (ORIF)

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9
Q

in treating zygomatic fractures, what is ORIF dependent on?

A
  1. degree of comminution
  2. stability of fracture
  3. presence of other features:
    - orbital content/ volume derangement
    - facial symmetry
    - inf orb nerve issues
    - functional issues
    - associated fractures
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10
Q

what are the 4 poor outcomes of zygomatic fracture tx?

A
  • inadequate tx
  • inadequate exposure
  • inadequate reduction
  • failure to restore orbital volume
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11
Q

what tx is required for a displaced, minimally comminuted zygomatic fracture?

A

ORIF

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12
Q

how is a non-displaced ZMC confirmed?

A

CT scan

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13
Q

tx for non-displaced ZMC?

A

non-surgical mx
monitor for facial asymmetry and functional deficit
soft diet

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14
Q

tx required for displaced, minimally comminuted ZMC?

A
  1. reduction alone
  2. fixation (1point,2 point,3 point+orbital floor)

best managed with ORIF at 2/3 points

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15
Q

what is the risk of just reducing a ZMC fracture?

A

displacement

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16
Q

where is one-point fixation carried out?

A

zygomaticomaxillary buttress

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17
Q

where are the 3 points for reduction?

A

frontozygomatic suture
zygomaticomaxillary buttress
inferior orbital areas

18
Q

what are the advantages of ORIF?

A

improved alignment
fixation of zygomaticomaxillary buttress provides vertical support
orbital rim exposure allows inspection of orbital floor
inspection of fractures sites prior to closure

19
Q

when exploring the orbital floor, what do we look for?

A

defects larger than 5mm on CT scan
severe displacement
comminution
soft tissue entrapment with limited upwards gaze
orbital contents herniation into max sinus

20
Q

when do you consider reconstruction of the orbital floor?

A

enophthalmos
larger defects (5-10mm)
defects posterior to the axis of the globe

21
Q

when do you consider 2 point fixation of ZMC fractures?

A
  1. minimally displaced fractures
  2. zygomaticomaxillary complex fracture remains stable after initial reduction with no palpable step deformity in infraorbital rim
  3. minimal changes on orbital vol and globe displacement is not evident on CT scan
22
Q

when do you consider 3 point fixation of ZMC fracture?

A

instability
exploration of orbital floor required

23
Q

list the fixation methods?

A

Kirschner Wires
Lag screw fixation
wire osteosynthesis
titanium plates and screws

24
Q

what are the 4 sites of fixation?

A
  1. frontozygomatic
  2. infraorbital margin
  3. zygomaticomaxillary buttress
  4. zygomatic arch
25
Q

what is the aim of reduction?

A

to provide force in the direction opposite to that which caused the fracture and to re-approximate the bone to the original position

26
Q

what are the reduction options?

A
  1. stab incision and intro of an instrument
  2. intra-oral approach
  3. screw insertion
    4.carroll-girard T-bar screw
27
Q

what does stab incision and instrument reduction involve?

A

introduction of an instrument (percutaneous bone hook) to hook under the bone to provide traction

28
Q

what does the intra-oral reduction approach involve?

A

vestibular incision and introduction of bone hook to hook under bone and provide traction

29
Q

what does screw reduction involve?

A

insert screw percutaneously and wire threaded through to manipulate

30
Q

for isolated arch fractures, where can you approach from?

A

oral or temporal

31
Q

describe gillies temporal reduction?

A

incision in hair line - superior and anteriorly to the helix of the ear (avoid the superficial temporal artery)
dissect temporalis fascia
incise temporalis fascia
introduce instrument and navigate beneath zygomatic arch
introduce elevator to reduce

no requirement for fixation

32
Q

what are the 2 gillies temporal instruments and what do they do?

A

bristow - lifts laterally and superiorly
rowe - provides traction through additional handle

33
Q

explain fixation of the frontozygomatic suture?

A

surgical exposure of suture
apply mini plates and screws

34
Q

explain fixation of the zygomaticomaxillary buttress?

A

intraoral vestibular approach
plates along fracture line and screws in place

35
Q

what does 3 point fixation include?

A

frontozygomatic suture
zygomaticomaxillary buttress
infra orbital margin

36
Q

where does 2 point fixation include?

A

frontozygomatic and zygomaticomaxillary butress regions

37
Q

describe orbital floor repair/ grafting?

A

Molded orbital floor plate - orbital contents are lifted and plate placed underneath to replace unstable fractures, supporting contents of the orbit

38
Q

what does 4 point fixation include?

A

reconstruction of the zygomatic arch through a bicoronal flap

39
Q

list the complications to ZMC surgery?

A

pain
facial asymmetry
scarring
bleeding
hardware failure
infraorbital nerve paraesthesia
temperature sensitivity
facial paresis or paralysis
poor cosmetic result
trisimus

40
Q

what does an eye exam include?

A

visual activity
visual fields
extraocular movements

41
Q

what are the complications of orbital reconstruction?

A

decreased visual activity
ectropion/ entropion/ lip malposition
corneal exposure/ abrasion
ptosis
epiphora
diplopia
blindness
SOFS
RBH+OCS