Maxillofacial

Question 1

Lone protrudor mandible

Answer 1

Lateral pterygoid

Question 2

Inward displacement mandible

Answer 2

Lateral and medial pterygoid

Question 3

Vertical buttress

Answer 3

Nasomax
Pterygomax
Zygomatfront
Zygomatmax

Question 4

Maximum bite forces(3)

Answer 4

200-300n incisors
300-600n premolar
500-700n molars

Question 5

Forces acting on the mandible

Answer 5

Tension
Compression
Torsion (symphysis)

Question 6

Observation and ff up for a greenstick considered a

Answer 6

Treatment

Question 7

4 surgical steps in fx management

Answer 7

Adequate exposure

Fragment reduction : goal establish preinjury bone anatomy prior to reduction

Adequate internal fixation

Meticulous wound closure - muscle and periosteal resuspension

Question 8

Bone healing

Answer 8

Primary - no motion across fx. Only titanium

Secondary- callous formation
No BH

Question 9

Secondary bh cascade?

Answer 9

Hematoma - fibroblasts occur

Granulation/connective tissue formation - increased stiffness

Compact bone - mineralization from fragment ends toward center of fracture gap.

Do reduction <2 weeks to prevent cascade

Question 10

Delayed union?

Answer 10

Clinically prolonged healing period but cascade is similar

<3 mos healing

Question 11

Non union bh?

Answer 11

> 3mos healing

Fragment ends too wide

Question 12

Le fort 1 (guerin)

Answer 12

Horizontal sep maxilla. From base of maxillary sinus to lower border nasal septum and pterygoid

Question 13

5 articulations of zm:

Answer 13

Frontal process/zf butres
Zm buttress/zm but
Inf orbital rim
Zyg arch
Zygosphenoid /zs but

Question 14

If 2 point fixation zmc?

Answer 14

Zf and zm (if 2 point)

Zm- strongest mastication butress
Zf- strongest butress

Ideally 5 point fixation

If 1 point either zf or zm

Question 15

Accuracy of reduction in desc

Answer 15

Zs
Zygomatic arch
Zm but
Infraorbital room
Zf shture line

Question 16

Stable fix

Answer 16

Zm
Zf
zs
Zygo arch
Infraorbital rim

Question 17

Blow out fx types?

Answer 17

Pure only orbital floor

Impure may orbital rim

Question 18

Where teardrop sign seen

Answer 18

Waters view xray

Question 19

Kazanjian and Converse
Forces per square inch to fracture?
Frontal?
Nasal?
Premaxilla?
Mentum to the mandible?
Condyle?
Zygoma?

Answer 19

120-180G
39-80G
150G
70-110G
35-80G 
50-80G

Question 20

Timing of reduction after nasal bone injury?

Answer 20

Asap 1-2 h after injury
After 2-3 days for swelling to subside
<10 days before fibrous development (10-14d)

Question 21

Nasal bone reduction possible until how many days?

Answer 21

21 days

Question 22

Intranasal packs are in place for how long?

Answer 22

3-5days

Question 23

Nasal splints are in place for how long?

Answer 23

7-10days

Question 24

Mandibular body is until what area?

Answer 24

Between 2nd and 3rd molar

Question 25

Classification of dentures?

Answer 25

Class I - dentulous, dentition on both sides of the fx Class II - some dentition present Class III - completely edentulous

Question 26

Comprises mandibular xray series?

Answer 26

APO

Question 27

For condylar fx, what x ray view can be used?

Answer 27

High townes view

Question 28

Imaging of choice for mandibular fx?

Answer 28

Panorex

Question 29

How many screws for screw IMF?

Answer 29

4-6

Question 30

Absolute indications for open reduction of condylar fx? (4)

Answer 30

1. Condylar displacement into middle fossa 2. Inability to obtain reduction 3. Lateral extracapsular displacement of the condyle 4. Invasion by a foreign body

Question 31

What are the indirect signs of fracture on ct?

Answer 31

Air fluid level Complete opacification of the sinus with blood Gas outside the sinus

Question 32

Divisions of occipital bone?

Answer 32

Basioccipital Condylar Squamosal

Question 33

Strane and robertson classification of nasal fractures by depth of injury?

Answer 33

Plane 1: anterior nasal spine, anterior septum, lower ends of the nasal bones Plane 2: greater nasal bone fracture but does not involve the orbital rims Plane 3: NOE complex disruption