Mid-Third Facial Bone Fractures – Prof. F.N. Chukwuneke (16/01/2014)

These question-and-answer flashcards summarise key anatomy, classifications, clinical signs, imaging, and management principles of mid-third facial bone fractures, including Le Fort, zygomatic, orbital, and nasal injuries.

What anatomical boundaries define the mid-third facial skeleton?

Superiorly: line from one zygomaticofrontal suture across the frontonasal & frontomaxillary sutures to the opposite zygomaticofrontal suture; Inferiorly: occlusal plane / alveolar ridge; Posteriorly: frontal bone above and body of sphenoid below.

Which two main functions does the detachable mid-facial framework serve?

1) Protects the brain from head trauma; 2) Forms the bony buttress safeguarding the globes and optic nerves.

List at least four bones that make up the mid-facial skeleton.

Examples: the two maxillae, two zygomatic bones, two palatine bones, vomer, ethmoid with conchae, nasal bones, lacrimal bones, inferior conchae, zygomatic processes of temporal bone, pterygoid plates of sphenoid.

Name four common aetiological factors for mid-third facial fractures.

Assaults, road-traffic accidents, sports injuries, falls (also industrial, domestic, war injuries).

Who first described the classic three weak lines of mid-facial fractures and in what year?

René Le Fort in 1901.

What characteristic pattern defines a Le Fort I fracture?

Horizontal, low-level fracture detaching the maxillary tooth-bearing segment from the midface; passes above the teeth, below the zygomatic process, through maxillary sinuses to inferior pterygoid plates.

Which Le Fort level is termed a ‘pyramidal fracture’?

Le Fort II.

Through which key anatomical areas does a Le Fort II fracture run?

Nasal bones, frontal processes of maxillae, lacrimal bones, orbital floors, zygomaticomaxillary sutures, lateral maxillary wall, pterygomaxillary fossa, pterygoid plates.

What is another name for a Le Fort III fracture?

Craniofacial dysjunction.

How does a Le Fort III fracture separate the face from the cranium?

Fracture line passes nasofrontal/frontomaxillary sutures, orbital floors, ethmoid & sphenoid sinuses, zygomaticofrontal suture, and across both pterygoid plates.

Give three cardinal clinical signs of Le Fort fractures.

Pain; Facial swelling/edema; Step deformity (others include mobility, anaesthesia/paraesthesia, diplopia, epistaxis, subconjunctival haemorrhage, CSF rhinorrhoea, etc.).

Which sign in Le Fort fractures produces a metallic ‘cracked-pot’ note on maxillary percussion?

Cracked-pot sound.

Henderson’s Class II malar fracture refers to what specific injury?

Isolated zygomatic arch fracture.

What is a ‘tripod’ fracture in Henderson’s malar classification?

Fracture involving zygomatic arch, orbital rim, and maxillary buttress (Class III if undistracted frontozygomatic suture, Class IV if distracted).

In Row & Williams (1985), which Le Fort levels fall under “sub-zygomatic” fractures affecting occlusion?

Le Fort I and Le Fort II.

State the five categories in the lateral (zygomatic) fracture classification.

1) Nondisplaced; 2) Displaced; 3) Comminuted; 4) Orbital wall fracture; 5) Zygomatic arch fracture.

Which walls of the orbit are formed by the zygoma?

Lateral wall and floor of the orbit.

Name two facial expression muscles that attach to the zygomatic bone.

Zygomaticus major and zygomaticus minor (others: levator labii superioris, levator anguli oris, masseter).

Which sensory nerve lies about 10 mm below the inferior orbital rim?

Infra-orbital nerve.

What percentage of zygomatic bone fractures are associated with ocular injuries?

Approximately 40 %.

List four clinical features you would look for when examining a suspected zygomatic fracture.

Malar depression/asymmetry, step deformity, trismus (limited mandibular movement), periorbital haematoma (also pain, swelling, gagging of occlusion, subconjunctival haemorrhage, tenderness).

Which standard plain-film view is most widely used to screen mid-face fractures and at what two angles are additional projections taken?

Occipitomental (O.M.); additional views at 10° and 30° cranial angulation.

What imaging modality provides three-dimensional evaluation essential for present-day midface reconstruction?

3-D computed tomography (CT) scanning.

Describe the radiographic ‘baseline’ used to position a patient for mid-face radiographs.

A line running from the outer canthus of the eye to the external auditory meatus.

Within what time frame does early surgical treatment of most maxillofacial fractures yield the best results?

Within 1–10 days after injury.

Give three common fixation methods for mid-facial fractures.

Wiring, plates & screws, inter-maxillary fixation (IMF) (also internal or craniofacial suspension techniques).

Which classic temporal approach is commonly used for closed reduction of depressed zygomatic fractures?

Gilles temporal approach (1927).

What intra-oral approach described in 1909 can elevate the zygoma?

Keen intra-oral approach.

Name two key structures related to isolated orbital floor fractures.

Inferior rectus muscle and infra-orbital nerve (others: antrum, optic nerve at apex, lacrimal duct, etc.).

List three typical symptoms of a blow-out orbital fracture.

Diplopia, proptosis, paraesthesia of the cheek (others: circumorbital & subconjunctival haemorrhage).

What bedside test helps confirm inferior rectus entrapment in a blow-out fracture?

Forced-duction test (immobile eye indicates entrapment).

On occipitomental radiographs, how is herniated orbital fat into the antrum often described?

‘Hanging-drop’ sign.

State two emergency measures for acute postoperative orbital compartment syndrome.

Immediate orbital decompression and elevation of the head (others: remove dressings, give mannitol or acetazolamide).

Give three clinical features of acute nasal complex fracture.

Bilateral circumorbital ecchymosis (medially), nasal deviation/saddle depression, epistaxis (others: marked edema, subconjunctival haemorrhage medially, CSF rhinorrhoea).

What instruments are classically used for reduction of displaced nasal fractures?

Walsham’s and Asch forceps.

List four long-term complications that may follow mid-third facial injuries.

Post-concussional syndrome (headache, dizziness), facial bone deformity such as flattened cheek, limited jaw excursion, diplopia (others: insomnia, neuropraxia/neurotmesis, dacryocystitis, non-union, ‘dish-face’ deformity).