Fractures of the mandible

Question 1

What are the clinical signs and symptoms of a fracture of the mandible?

Answer 1

Pain, swelling, limitation of function
Occlusal derangement
–one segment may be dislocated
–unable to close teeth together or not meeting as they used to
Numbness of lower lip
Loose of mobile teeth
Bleeding
Anterior open bite
Facial asymmetry
Deviation of the mandible to the opposite side

Question 2

What causes deviation of the mandible to the opposite side?

Answer 2

Lateral and medial pterygoid from fracture side will not work properly

Question 3

How can a fracture of the mandible cause an anterior open bite?

Answer 3

A bilateral fracture around the condyle
The ramus shortens and creates an anterior open bite

Question 4

What are the classifications of mandibular fractures involving the surrounding bone?

Answer 4

Simple
Compound
Comminuted

Question 5

What is a simple fracture of the mandible?

Answer 5

Fracture in bone and the surrounding soft tissue is intact

Question 6

What is a compound fracture of the mandible?

Answer 6

Soft tissue surrounding is damaged, lacerated or exposing the fracture

Question 7

When is a comminuted fracture of the mandible?

Answer 7

When bone has been broken into multiple small pieces (gunshot wound)

Question 8

How do you classify the number of fractures of the mandible?

Answer 8

Single
–1 fracture line
Double
–2 fracture lines
Multiple
–3 or more fracture lines

Question 9

What different sites of a fracture can you have of the mandible?

Answer 9

Angle
Subcondylar
Parasymphyseal (chin area)
Body
Ramus
Coronoid process
Condylar fracture (intra or extra capsular)
Alveolar process

Question 10

What is a favourable direction of a fracture line?

Answer 10

If the fracture line minimises displacement

Question 11

What is an unfavourable direction of a fracture line?

Answer 11

If the fracture line encourages displacement

Question 12

What are green stick fractures?

Answer 12

Happens in children due to organic component of the bones
Bones are softer- fracture happens and does not have complete separation

Question 13

What are the factors that cause displacement of mandibular fractures?

Answer 13

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

Question 14

What is the management of mandibular fractures?

Answer 14

Clinical examination
Radiographic assessment
Treatment

Question 15

What is the treatment of mandibular fractures?

Answer 15

Control of pain and infection
2 basic principles
–Reduction (correct position of fracture)
–Fixation (fix back into correct position)

Question 16

What is the treatment of an undisplaced fracture?

Answer 16

Surgical treatment
Antibiotics for compound fractures
Soft diet and spontaneous fix

Question 17

What is involved in a closed reduction & fixation (IMF)?

Answer 17

Depend on patients occlusion to guide reduction
Wire teeth together for 4-6 weeks (intermaxillary fixation) and fracture will repair- fix away from fracture using teeth (liquid diet, hard to keep clean)

Question 18

What patients are contraindicated for having their teeth wired together (closed reduction & fixation)?

Answer 18

Epileptic patients
Can have a fit and die if they vomit

Question 19

What is involved in an open reduction & internal fixation (ORIF)?

Answer 19

Expose bony edges surgically- reduce directly with vision and fix into place with screws
Plates made from titanium

Question 20

When would you not open a fracture?

Answer 20

Infected fracture (adds to infection and healing will be compromised can end up with osteomyelitis)

Question 21

What are absolute indications for ORIF?

Answer 21

Bilateral subcondylar fracture with anterior open bite tendency
Displaced condylar fracture that interferes with mouth opening
Displaced fracture in the middle cranial fossa
Displaced fracture that causes occlusal derangement
Displaced fracture that causes ramus shortening

Question 22

What are the pathological causes of a mandibular fracture?

Answer 22

Generalised bone disease- Pagets
Osteogenesis imperfecta
Osteoporosis
Fibrous dysplasia
Hyperparathyroidism
Localised bone disease
–Osteomyelitis
–ORN
–Cysts/odontomes
–Tumours- neoplasma
–Benign/malignant

Question 23

What does the displacement of fragments depend on?

Answer 23

Pull of attached muscle
Angulation and direction of fracture line
Integrity of periosteum
Extent of comminution

Question 24

What are some complications of a condylar fractures?

Answer 24

Trismus- clicking and locking
Osteoarthritis
Subluxation
Late trismus
Deviation to affected side
Ankylosis and asymmetry
Open bite
Neurological
Vascular