Fractures Of The Zygomatic-Maxillary Complex

Question 1

SIGNS AND SYMPTOMS OF FRACTURES OF THE ZYGOMATICO –
MAXILLARY COMPLEX (ZMC)

Answer 1

1. Swelling
2. Circumorbital ecchymosis
3. Subconjunctival haemorrhage with no limit
4. Depression
5. Epistaxis
6. Diplopia (double vision)
7. Opthalmoplegia
8. Ptosis (drooping of the upper eyelid)
9. Enophthalmos
10. Trismus and limitation of mandibular opening
11. Pain
12. Anaesthesia
13. Step defects

Question 2

Swelling

Answer 2

This sign is dependent on when the patient presents following injury.
After a day or two, swelling may become so extensive that fracture lines may not
be palpable nor orbital contents be examined. A rare, but threatening finding is
the development of surgical emphysema. This may be the result of blowing of
the nose (the walls of the antrum being fractured) or spontaneously. It may
propagate spontaneously and on palpation crepitus may be elicited (the
expansion contains locules of air). The airway may be threatened.

Question 3

Circumorbital ecchymosis

Answer 3

Usually the result of perfusion of blood around and
into the orbicularis oculi muscle.

Question 4

Subconjunctival haemorrhage with no limit

Answer 4

There is no lateral limit of this haemorrhage when the patient looks to the opposite side. In about 70% of cases
this is indicative of a fracture of ZMC.

Question 5

Depression

Answer 5

This may involve the malar (zygomatic body) eminence or the
zygomatic arch. Its presence is usually only assessed shortly after the traumatic
event or after some days when the swelling subsides. It is sometimes only
treated if the patient complains of a cosmetic deformity (in the case where there
is no significant damage to vital structures)

Question 6

Epistaxis

Answer 6

This may occur on the side of injury when the ZMC fracture involves
disruption of sinus linings (especially the maxillary sinus / antrum).

Question 7

Diplopia

Answer 7

This may resolve spontaneously, but sometimes it is an
ominous sign of significant intra – orbital damage e.g.
a. Damage to the globe- lens detachment, retinal haemorrhage.
b. Transient intra – orbital pressure.
c. Displacement of Whitnall’s tubercle (as mentioned earlier).
d. Gross prolapse of orbital contents into the maxillary antrum, increasing orbital
volume and may change pupillary level.
e. Entrapment of the inferior oblique and / or the inferior rectus into a fracture of
the orbital floor.

Question 8

Opthalmoplegia

Answer 8

This may occur as a result of damage to the contents of the
superior orbital fissure or may be as a result of central nervous system damage.

Question 9

Ptosis (drooping of the upper eyelid):

Answer 9

Frequently there is a pseudo ptosis present, the result of oedema and haematoma formation. True ptosis is rare, e.g. damage to Muller’s muscle.

Question 10

Enophthalmos

Answer 10

This is usually assessed once the swelling in the area is
reduced. The globe appears retro displaced, when compared to the other globe
position. It is usually the result of increased orbital volume and produces an
aesthetic problem and / or diplopia.

Question 11

Trismus and limitation of mandibular opening

Answer 11

This is usually the result of a fractured zygomatic arch, impinging on the temporalis muscle and
will often release (N.B. in fresh fractures) on induction and deepening of general
anaesthesia. Occasionally the coronoid process is impinged on by the zygomatic
arch and this is a more serious condition. It may complicate the administration of
general anaesthesia. If left untreated it may result in temporo – coronoid fibrosis,
and little oral opening results

Question 12

Pain

Answer 12

This is usually not severe, but there is always a rare long term possibility
of its development e.g. from damage to the infra – orbital nerve.

Question 13

Anaesthesia

Answer 13

The area supplied by the sensory supra – orbital nerve is
common. It may be transitory or improve after surgical decompression occurs
when reducing the ZMC fracture. Other sensory nerve damage is rare.

Question 14

Step defects

Answer 14

A classic ZMC fracture may produce a palpable step at the infra
– orbital rim. Also palpated may be a step defect intra – orally at the zygomatic
buttress. This may be associated with a haematoma at the site.

Question 15

Submentovertex view (“jug handle view”)

Answer 15

This provides excellent view of the zygomatic arches. Very severe fractures may also
be illustrated by this view.

Question 16

Occipitomental views (15 and 30 degree view)

Answer 16

These views provide excellent illustration of maxillary sinus, zygomatico – frontal sinus, walls
of the orbit, relative positions of the zygomatic arch to the coronoid process. If
one side only is affected, the size and shape of the orbits should be compared.
The affected side may be larger or smaller, indicating that the bony walls of the
orbit have been compromised. Partial of full radio – opacity of the maxillary sinus
is often visualised. This usually means that the sinus (antrum) has partially or
completely filled with blood (see occipitomental radiograph below).

Question 17

Computerised scanning (CT):

Answer 17

If this facility is available it is of enormous benefit. Axial, coronal, sagittal “cuts” at various levels are visualised. These demonstrate the fractured areas with great sensitivity. It is important that the
inexperienced surgeon should not “over diagnose” from information supplied by
these views. Remember that the correct clinical examination is paramount. It is
also possible to obtain three dimensional scans, reformatted from other views. At
the time of writing, these (while easy to interpret) may not provide very accurate
information.

Question 18

Le Fort I

Answer 18

This is a low level subzygomatic fracture. The fracture line runs from the Lateral
margin of the anterior nasal aperture in a lateral and posterior direction, above the
apex of the maxillary teeth. Thus the bone associated with the canine fossa and
lateral maxillary antral wall are fractured usually fairly horizontally. The fracture
crosses to the lower third of the cribriform plates. In order to complete the fracture,
the medial wall of antrum is involved and separation of the nasal septum occurs.

Question 19

Le Fort II

Answer 19

This is a pyramidal subzygomatic fracture. The fracture begins in the region of the
glabella, then runs laterally across the nasal bones to cross the frontal process of the
maxilla. The fracture line then turns downwards and passes across the lacrimal
bones and anteriorly across the thicker bone of the nasolacrimal canal. The line
continues downwards, involving in the region of the zygomatico – maxillary suture. It
continues close to the infraorbital foramen, across the lateral part of the maxillary
antrum and ends in about the middle of the pterygoid plates. Corresponding internal
fractures allow mobility of the fractured complex.

Question 20

Le Fort III

Answer 20

This represents a craniofacial disjunction. It is a high level suprazygomatic fracture.
The fracture line begins near the frontonasal suture and continues laterally and
slightly downwards along the superior aspect of the frontonasal area and up to
involve the frontozygomatic suture. In the process the orbital plate of the delicate
ethmoid bone is involved and the fracture passes across the inferior orbital fissure
and then on through the rim of the orbit near the infra – orbital canal, crossing above
the zygomatic body to the upper aspect of the pterygoid plates. The zygomatic arch
is also fractured. Similar interior fractures complete the complex and these fracture
lines bilaterally.

Question 21

Examples and some tips on emergency management: Epistaxis and general facial bleeding from lacerations.

Answer 21

The patients face may be covered in blood, but rapid surface cleaning with wet swabs and the use of good
suction usually displays the bleeding areas e.g. epistaxis may be controlled by
pressure (possible insertion of packs). Lacerations may be rapidly sutured – fine
suturing can be performed later. Of course, a good deal of blood may be
aspirated and generally the patient may be placed on the side. Cervical fracture
may be present and movement of the unsupported neck may be disastrous. It is
best to consult a trauma (or other experienced) surgeon before this
repositioning.

Question 22

Serious airway threat management:

Answer 22

This may occur, usually associated with Le Fort III
fractures in that the midface is driven backwards and down the incline of the
cranial bones onto the posterior aspect of the pharynx, obstructing the airway.
Two fingers placed around the posterior aspects of the soft palate may allow
some reduction of the fracture, assisting with airway management. Endotracheal
tubes may be placed in order to protect the airway. The mid – face fracture may
be impacted and impossible to move without general anaesthesia. This may
result in great difficulties and sometimes an oro – pharyngeal / naso –
pharyngeal tube placed behind the tongue may help greatly. Remember anoxia
kills. Cricothyroidotomy may be life saving. An urgent tracheostomy, performed
rapidly by a skilled surgeon and provides a definitive airway.

Question 23

Management of midface fractures

Answer 23

The management principles are as follows:
1. Mobilisation and reduction of the fragments in a systematic order.
2. Alignment – numerous fracture sites may have to be mobilised in order to
achieve this.
3. Open reduction and fixation with microplates
4. Prevention of infection.
5. Restore function and aesthetics