facial bone pathology

Question 1

evidence of a pathology

Answer 1

fluid levels
linear lucency
cortical break
widened suture
bone fragments overlapping
soft tissue swelling
asymmetry

Question 2

what is dolan’s line

Answer 2

• follow margins of the zygoma, orbital margins and maxilla
• looks like an elephant
• useful because zygoma is frequent site of fracture

Question 3

how to spot a zygomatic fracture

Answer 3

• elephants trunk appearance

- compare sides to see an abnormal contour

Question 4

what is McGrigors’ lines

Answer 4

• system for checking OM view
• three lines
• fluid levels and fractures

Question 5

line 1 of McGrigors lines

Answer 5

through suture between frontal bone and zygomatic bone, across forehead, assessing the superior orbital margin and frontal sinus and follow same landmarks the other side
looking for widening of the zygomatic-frontal suture and fluid level in frontal sinus

Question 6

line 2 of McGrigors lines

Answer 6

up along the zygomatic arch crossing the body of the zygoma, continue on inferior margin of the orbit and over the bride of the nose
look for fractures of zygomatic arch or a fracture through the inferior rim of the orbit

Question 7

line 3 of McGrigors lines

Answer 7

trace a line along the inferior margin of the zygomatic arch, down the lateral wall of the maxillary antrum and along the inferior margin of the antrum, across the maxilla including the roots of the upper teeth
look for fractures of the zygoma and lateral aspect of maxillary antrum fluid levels

Question 8

4 components of tripod ZMC fracture

Answer 8

1. widening of zygomatic frontal suture
2. orbital floor fracture
3. fracture of lateral wall of maxillary antrum
4. zygomatic arch fracture
   increased density of maxillary antrum is due to it filling with blood

Question 9

causes of tripod ZMC fracture

Answer 9

• personal altercations
• falls
• RTCs
• sports injuries

Question 10

symptoms of tripod ZMC fractures

Answer 10

• trismus = reduced jaw mobility resulting from compression of zygomatic arch on the temporalis muscle and coronoid process
• subcutaneous emphysema due to orbital floor disruption
• infraorbital nerve injury causing anaesthesia of cheek, nose, upper and lower eyelid

Question 11

treatment of tripod ZMC fractures

Answer 11

• non-displaced= managed without surgery needs ophthalmologic examination
• complex = assessed several days after injury when much of tissue oedema has resolved
  aim to gain stable reduction while minimising external scars and functional deformity

Question 12

management of tripod ZMC fractures

Answer 12

• observation, antibiotics, possible steroid administration to reduce oedema and examinations to check diplopia

Question 13

what is diplopia

Answer 13

an upward and far lateral gaze caused by nerve damage or muscle contusion

Question 14

causes of blowout fracture

Answer 14

RTCs
industrial accidents
sport
assault

Question 15

mechanism of a blowout fracture

Answer 15

• pressure anteriorly results in fracture of orbital wall

- can cause ocular motility disturbance and globe malpositioning

Question 16

what is a trap door blow out fracture

Answer 16

also called greenstick
intra-orbital tissue becomes entrapped in fracture as the elastic bones snap back into place.
results in potentially severe restrictive optical issues

Question 17

symptoms of blowout fracture

Answer 17

diplopia
severe epistaxis (nose bleed)
CSF leakage
lacrimal drainage problems

Question 18

treatment of blow out fracture

Answer 18

antibiotic
analgesia
oral steroids to reduce oedema 
surgical repair 
possible lens implants

Question 19

management of blowout fracture

Answer 19

diplopia, muscle and nerve damage should be monitored for 6 months