mandibular fracture

Question 1

Name 4 clinical signs and symptoms of mandibular fracture?

Answer 1

Any from:
- pain, swelling, limitation of function
- occlusal derangement
- numbness of the lower lip
- loose or mobile teeth
- bleeding
- anterior open bite
- facial asymmetry
- deviation of the mandible to the opposite side

Question 2

How may muscles cause mandibular displacement?

Answer 2

Muscles work in opposite actions eg - masseter, temporalis and medial pterygoid elevate the mandible and geniohyoid and anterior belly of digastric depress the mandible

Question 3

How may damage to the muscles that elevate and depress the mandible present and why is this?

Answer 3

Lowe lip numbness - inferior alveolar nerve damage

Question 4

How are mandibular fractures classified based on involvement of the surrounding tissue?

Answer 4

Simple - in the bone but surrounding soft tissue is intact
Compound - affecting the surrounding soft tissue
Comminuted - bone is broken into multiple small pieces

Question 5

How are mandibular fractures classified based on the number of the fractures?

Answer 5

Single
Double
Multiple

Question 6

How are mandibular fractures classified based on the side of the fracture?

Answer 6

Unilateral
Bilateral

Question 7

How are mandibular fractures classified based on the site of the fracture? (8)

Answer 7

Angle
Subcondylar
Parasymphyseal
Body
Ramus
Coronoid
Condylar fracture (intra or extra capsular)
Alveolar Process

Question 8

How are mandibular fractures classified based on the direction of the fracture line (relates to the displacement)?

Answer 8

Favourable - minimises displacement
Unfavourable - encourages displacement

Question 9

How are mandibular fractures classified based on specific features?`

Answer 9

Green stick fractures - occurs in children, because of organic content of bone, it is softer and there may not be complete separation
Pathological fractures - caused by expanding lesions in the bone

Question 10

How are mandibular fractures classified based on displacement of the fracture?

Answer 10

Displaced
Undisplaced

Question 11

What 6 factors cause the displacement of mandibular fractures?

Answer 11

Direction of the fracture line
Opposing occlusion
Magnitude of force
Mechanism of injury
Intact soft tissues
Other associated fractures

Question 12

What radiographs are used to assess mandibular fractures?

Answer 12

2 radiographs at right angle to each other (OPT and PA mandible)
Most often get CBCT

Question 13

How are mandibular fractures treated?

Answer 13

Control pain and infection
Reduction - putting the 2 fractured segments into the right anatomical position
Fixation

Question 14

What are the options for carrying out fixation?

Answer 14

Closed reduction and fixation (IMF - intermaxillary fixation)
ORIF - open reduction and internal fixation

Question 15

When must fixation be carried out?

Answer 15

if fractures are displaced or mobile

Question 16

What is open reduction?

Answer 16

Exposing the bony areas surgically and reduce them directly with vision - most - commonly done now

Question 17

What is closed reduction?

Answer 17

You don’t open the fracture - you depend on the patients occlusion to guide the fracture into the correct alignment

Question 18

What is the main difference in tx between displaced and undisplaced mandibular fractures?

Answer 18

Displaced fractures need tx
Undisplaced fractures may not need active tx

Question 19

What is the contraindication to intermaxillary fixation (IMF)

Answer 19

Epileptic patients

Question 20

What is a Gunning splint?

Answer 20

Using a patients denture to help correct a fracture - historic

Question 21

When can you be sure that a mandibular fracture is compound when only seeing a radiograph?

Answer 21

Any fracture involving the teeth is a compound fracture

Question 22

What are the 5 surgical approaches for mandibular fractures?

Answer 22

Retro-mandibular approach
Raised on approach from the inferior border
Preauricular approach
Bi-coronal flap - from one ear to the other
Endoscopic reduction and fixation

Question 23

What is a step deformity?

Answer 23

An irregularity in the alignment of adjacent bone segments causing a visible or palpable step-like change in the bone contour - a sign of a mandibular fracture