OS- Fractures (Mand & Zygoma)

Question 1

What muscles close the mandible?

Answer 1

Medial pterygoid
Temporalis
Masseter

Question 2

What muscles open the mandible?

Answer 2

Suprahyoid
Mylohyoid
Anterior belly of digastric.

Question 3

What is the nerve supply for the mandible?

Answer 3

Inferior alveolar dental nerve

Question 4

List signs and symptoms of mandibular fractures?

Answer 4

Pain/Swelling / limitation of function.
Occlusal derangement (not biting properly)
Bony step deformity
Loose or Mobile teeth
Numb lip
Bleeding (limited to where the fracture is)
Anterior open bite (if the fracture causes a shortened ramus)
Facial assymetry
Deviation of the mandible to the opposite side

Question 5

What do we use to classify a fracture?

Answer 5

Involvement of the surrounding tissue.
Number of fractures
side of fractures
Site of fractures
Direction of fracture line (Favourable or unfavourable)
If there is a specific type of fracture.
Any displacement of the fracture.

Question 6

Compare a simple a compound and a comminuted fracture?

Answer 6

Simple fracture- fracture still within the bone.
Compound fracture- fracture is exposed to the outside environment
Communiuted fracture- multiple pieces?

Question 7

How do we classify any fractures around the teeth bearing area and why?

Answer 7

Compound because the PDL is involved .

Question 8

What are the two directions of the fracture line?

Answer 8

Favourable- The position of the fracture line allows muscles to prevent further displacement
Unfavourable- direction of the fracture encourages further displacement.

Question 9

What is a greenstick fracture?

Answer 9

A fracture in children as the bone is still soft so it bends rather than breaks.

Question 10

Give causes of pathological fractures?

Answer 10

Expanding Cystic lesions.
Osteoporosis
Osteomyelitis

Question 11

How does the displacement of a fracture impact treatment?

Answer 11

If a fracture is displaced we need to reposition the fracture.
If the fracture is undisplaced we may not require surgical intervention.

Question 12

List some factors that can cause displacement of mandibular fractures?

Answer 12

The direction of the fracture line.
Opposing occlusion (can prevent the fracture being displaced)
The force of the fracture.
Mechanism of injury
Intact soft tissue (tells us if the fracture has been displaced)
Other associated fractures (Much higher chance of displacement if there are multiple fractures)

Question 13

How do we manage a mandibular fracture?

Answer 13

1. clinical examination
2. radiographs (take 2 radiographs such s an OPT and PA mandibular)
3. Control pain and infection (need to give antibiotics for compound fractures)
4. If it isn’t displaced( leave it) if it is displaced we will need to reduction and fixation.

Question 14

what are we looking for to identify a fracture on a radiograph?

Answer 14

radiolucent line .
Loss/ deformity of the medial border of the mandible
step in occlusion

Question 15

Compare open and closed reduction and fixation?

Answer 15

Open reduction & fixation- we reflect tissue to expose the fracture & reduce
Closed reduction- reducing the fracture without exposing the fracture line. This uses the intramaxillary fixation to assume if teetha re placed in the right place the mandible must be in the right position.

Question 16

What is neccessary if the patient has closed reduction & fixation ?

Answer 16

They need to have their teeth closed shut for 6 weeks.

Question 17

Give some indications for open reduction & Internal fixation of a condylar fracture?

Answer 17

Bilateral Subcondylar fracture with anterior open bite tendency.
A displaced fracture in the middle cranial fossa
a displaced fracture causing occlusal derangement
A displaced condylar fracture that interfereres with mouth opening.
A displaced fracture causing ramus shortening.

Question 18

What do orbital ethmoidal injuries include?

Answer 18

Medial wall.
anterior wall
Lateral wall
Roof
floor
Apex

Question 19

What structures are associated with the anterior wall of the orbit?

Answer 19

scerla
eyelid
cornea

Question 20

What structures are associated with the medial wall of the orbit?

Answer 20

Medial rectus muscle
Nose
lacrimal duct & sac
Medial canthal ligament
Ethmoid sinus cribiform plate.

Question 21

What structures are associated with the superior orbital fissure?

Answer 21

Oculomotor nerve III(eye muscles)
Trcohlear nerve IV (supplies superior oblique)
Abducent VI (Supplies lateral rectus)
Branches of the opthalamic nerve
Opthalamic veins.

Question 22

What structures are associated with the inferior orbital fissure?

Answer 22

Infraorbital nerve (supply to the undereye area)
Infra-orbital vein
Infra-orbital artery

Question 23

What are the symptoms of zygomatico-orbital trauma?

Answer 23

Pain/bruising/swelling

Numbness
Facial assymetry
Difficulty moving eye. (If damage to occulomotor nerve)
Restricted eye movement (due to entrapment of the muscles)
Diplopia (double vision)

Question 24

Identify these different types of bruising.

Answer 24

A-Subconjunctival ecchymosis
B- circumorbital ecchymosis

Question 25

list clinical signs of Cheek fracture?

Answer 25

Peri-orbital bruisinig and swelling
subconjunctival ecchymosis.
Sensory defect (infraorbital nerve)
Diplopia
Subcutaneous emphysema
Epitaxis (bleeding through the nose due to the connection with the nose through the middle meatus)
Step deformity

Question 26

Where should we palpate to check for cheek fracture?

Answer 26

Supraorbital ridge
Infraorbital ridge and zygoma
Depression of the zygomatic arch.
Manouvre to ascertain motion in the maxilla.

Question 27

How do we manage a zygomatico-orbital fracture?

Answer 27

1. check there is no occlular damage.
2. prophylactic antibiotic
3. advise patient to avoid blowing nose.

Review when swelling subsides
Further radiographs
Informed consent
Treatment (ORIF or CRIF)

Question 28

What is reduction and fixation?

Answer 28

Reduction is bringing the jaw into correct anatomy
Fixation is fixing it in place using plates and screws.