By MRCSA in MRCS Part A — 04 Jul 2026

21 FACIAL TRAUMA

# Detailed notes

Facial trauma is high-yield because it tests anatomy of the midface and mandible, V2/V3 distributions, and the ATLS-based airway priorities all at once.

Airway first — always

Facial trauma is an airway problem until proven otherwise. Bleeding, loose teeth, vomit, and a posteriorly displaced midface in Le Fort II/III can occlude the nasopharynx rapidly.

👩‍⚕️ Avoid nasal airways and NG tubes in suspected midface or basilar skull fractures — the tube can pass intracranially through a cribriform plate fracture.

Le Fort fractures — the unifying rule

The midface fractures along three predictable planes of weakness. The exam rule:

➡ All Le Fort fractures involve the pterygoid plates. If they are intact on CT, it is not a Le Fort fracture. Classification is by the highest fracture line; a patient may have different levels on each side.

Level	Fracture line	Mobile segment	Clinical hallmark
Le Fort I (Guérin)	Horizontal, above the teeth, through the lower maxilla and nasal septum	Hard palate and alveolus only	"Floating palate" — grasp upper teeth, only the palate rocks
Le Fort II	Pyramidal — through nasal bones, medial orbit, infraorbital rim, then down through the maxilla	Central midface (nose + maxilla + palate)	Pyramidal mobility, V2 numbness, subconjunctival haemorrhage, CSF rhinorrhoea possible
Le Fort III	Craniofacial dysjunction — through nasofrontal suture, medial orbit, lateral orbital wall and zygomatic arch	Entire midface separates from skull base	"Dish-face" deformity, whole midface mobile, high risk of CSF leak and dural tear

👩‍⚕️ Mnemonic — Palate, Pyramid, Plate-off-the-skull. Test by stabilising the forehead and rocking the upper incisors — what moves tells you the level.

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Zygomatic complex ("tripod") fracture

The zygoma articulates with frontal, maxilla, temporal and sphenoid. A direct blow to the cheek typically disrupts three of these joints.

➡ Flattened cheek (often masked by swelling)

➡ Step at the infraorbital rim

➡ V2 numbness — cheek, upper lip, lateral nose

➡ Trismus if the depressed arch impinges on the coronoid process

➡ Subconjunctival haemorrhage with no posterior limit

Orbital floor (blow-out) fracture

A blunt object larger than the orbital aperture (fist, squash ball) raises intra-orbital pressure; the thin floor decompresses downward into the maxillary sinus.

Classic triad:

➡ Enophthalmos — orbital volume increases as fat herniates into the antrum

➡ Diplopia on upgaze — inferior rectus tethered in the fracture

➡ V2 numbness — infraorbital nerve runs in the floor

CT shows the tear-drop sign — herniated orbital fat hanging into the maxillary sinus roof.

👩‍⚕️ Paediatric "white-eyed blow-out": the floor springs back and traps inferior rectus tightly. The eye looks normal but upgaze is locked and the child vomits (oculocardiac reflex). Surgical emergency.

Operate for: diplopia > 2 weeks, enophthalmos > 2 mm, or > 50% floor defect. Forced duction testing separates mechanical entrapment from oedema.

Nasal fracture

The commonest facial fracture. Check for septal haematoma — a boggy bluish swelling. Untreated it causes cartilage necrosis and saddle-nose deformity. Drain immediately; reduce the bones at 5–10 days once swelling settles.

Mandibular fractures

The mandible is a ring — like the pelvis, a single visible fracture should prompt a hunt for a second. Up to half are bilateral.

Sites by frequency:

➡ Angle — weakened by the third molar socket (commonest)

➡ Body — often paired with a contralateral angle fracture

➡ Condyle — common in children and from indirect chin trauma

➡ Symphysis / parasymphysis — direct anterior blow

➡ Ramus — uncommon; protected by masseter

Features: malocclusion (the patient knows their bite is "off"), trismus, step in the dental arch, sublingual haematoma (pathognomonic of body/symphysis fracture), and numb lower lip from inferior alveolar nerve injury.

The inferior alveolar nerve (V3) runs in the mandibular canal from lingula to mental foramen. Its terminal mental nerve supplies lower lip and chin. Protect at ORIF and consent for numbness.

Imaging

➡ CT face with fine (1 mm) cuts and coronal/3D reconstruction — gold standard for midface and orbit.

➡ OPG + PA mandible — workhorse for mandibular fractures and dental assessment.

➡ Occipitomental (Waters) view — screening only; misses complex and undisplaced fractures.

➡ MRI and ultrasound have no role in acute bony facial trauma.

[Image: MCQs banner]

Test yourself

A 30-year-old man is hit in the face and presents with a depressed zygoma, epistaxis, subconjunctival haemorrhage, infraorbital nerve numbness, and restricted eye movements with diplopia. What type of fracture?

((Nasal bone fracture::Causes epistaxis but not V2 numbness or restricted gaze.))
((Frontal bone fracture::Involves frontal sinus and anterior cranial fossa, not the infraorbital region.))
((Mandibular fracture::Lower jaw injury — no orbital or infraorbital signs.))
((Le Fort II::☑️ Pyramidal fracture through maxilla, infraorbital rim and nasal bones — explains V2 numbness plus orbital involvement.))
((Le Fort III::Would give complete craniofacial dysjunction with the whole midface mobile.))

A man is hit in the face with a heavy object. He presents with a flattened face and the entire midface is mobile relative to the base of skull. His forehead is stable. What fracture type?

((Le Fort I::Only the hard palate is mobile; midface stays put.))
((Le Fort II::Pyramidal central midface mobility — lateral midface remains attached.))
((Le Fort III::☑️ Craniofacial dysjunction — entire midface separates from skull base.))
((Zygomatic complex fracture::Depressed cheek but no full midface mobility.))
((Naso-orbito-ethmoidal fracture::Central midface and medial orbits only; no total separation.))

A patient sustained facial trauma and has a Le Fort I fracture. What structure is most at risk?

((Pterygoid plates::☑️ All Le Fort fractures cross the pterygoid plates — the unifying feature.))
((Frontozygomatic suture::Involved in Le Fort III, not I.))
((Orbital floor::Involved in Le Fort II and blow-out fractures.))
((Cribriform plate::At risk in Le Fort III and naso-ethmoidal injuries.))
((Inferior alveolar nerve::Lies in the mandible — unaffected by maxillary fractures.))

👩‍⚕️ Pterygoid plate involvement on CT is the entry ticket for any Le Fort diagnosis.

A patient with a maxillary fracture has only the hard palate mobile. Fracture type?

((Le Fort I::☑️ Horizontal fracture above the teeth — only the palate and alveolus float (Guérin fracture).))
((Le Fort II::Would also mobilise nose and infraorbital rim.))
((Le Fort III::Entire midface mobile relative to cranial base.))
((Alveolar ridge fracture::Only a tooth-bearing segment moves, not the whole palate.))
((Mandibular fracture::Palatal mobility means a maxillary injury, not mandibular.))

A 25-year-old boxer presents with vertical diplopia on upgaze after a blow to the left eye. Which muscle is most likely trapped?

((Superior rectus::Trapped only in rare orbital roof fractures; causes restricted downgaze.))
((Inferior rectus::☑️ Herniates through the orbital floor into the maxillary sinus, restricting upgaze.))
((Medial rectus::Trapped in medial wall fractures — much less common.))
((Lateral rectus::Not adjacent to a fracture-prone wall; entrapment is rare.))
((Inferior oblique::May be involved but is not the classic trapped muscle.))

A patient presents after facial trauma with enophthalmos, restricted upward gaze, and infraorbital numbness. Diagnosis?

((Orbital floor (blow-out) fracture::☑️ Classic triad — enophthalmos, inferior rectus entrapment, V2 numbness.))
((Le Fort I::No orbital involvement; isolated palatal mobility.))
((Zygomatic arch fracture::Causes trismus and cheek flattening, not enophthalmos.))
((Mandibular fracture::Lower jaw injury — no orbital signs.))
((Le Fort II::Can involve the floor but also gives midface mobility and nasal fracture.))

Which imaging modality is the gold standard for assessing midface and orbital fractures?

((CT face with fine cuts and coronal reconstruction::☑️ Best bony detail, shows fracture lines and soft tissue herniation.))
((Occipitomental (Waters) X-ray::Useful screening only — misses complex and undisplaced fractures.))
((MRI face::Excellent soft tissue but poor cortical bone — not first line.))
((Orthopantomogram::Workhorse for mandible and teeth, inadequate for midface or orbit.))
((Ultrasound::No role in acute facial fracture assessment.))

A man punched in the jaw presents with malocclusion, pain, and trismus. What is the commonest site of mandibular fracture?

((Body::Common, often paired with a contralateral angle fracture, but second overall.))
((Angle::☑️ Weakened by the third molar socket — the commonest single site.))
((Condyle::Common in children and from indirect chin trauma but not first overall.))
((Symphysis::From direct anterior force — less common.))
((Ramus::Uncommon — protected by masseter bulk.))

👩‍⚕️ The mandible is a ring — always look for a second fracture (often the contralateral condyle).

What nerve provides sensation to the lower lip?

((Inferior alveolar nerve (via mental nerve)::☑️ Branch of V3 — exits at the mental foramen to supply lower lip and chin.))
((Buccal nerve::Supplies cheek and buccal mucosa, not lip.))
((Lingual nerve::Anterior two-thirds of tongue — sensation and taste.))
((Long buccal nerve::Cheek mucosa over the molars — not lip.))
((Marginal mandibular nerve::Motor branch of VII to lip depressors, not sensory.))

During open reduction and internal fixation of a mandibular fracture, which nerve must be identified and preserved?

((Inferior alveolar nerve::☑️ Runs in the mandibular canal — directly in the fracture field.))
((Lingual nerve::Medial to mandible; at risk in third molar surgery, not ORIF of angle/body.))
((Marginal mandibular branch of VII::At risk in the submandibular approach but lies outside the bone.))
((Hypoglossal nerve::Deep in the submandibular triangle — not in the canal.))
((Mylohyoid nerve::Small motor branch — not the key structure at risk.))

👩‍⚕️ Always document and consent for lower lip numbness before mandibular ORIF.

# Revision summary

➡ Airway first. Avoid nasal tubes if midface or basilar skull fracture suspected.

➡ Le Fort rule: all involve pterygoid plates; classified by highest line.

- I — floating palate (horizontal, above teeth)

- II — pyramidal (nose + maxilla + infraorbital rim); V2 numbness, CSF leak possible

- III — craniofacial dysjunction; whole midface mobile, dish face

➡ Zygomatic (tripod): flat cheek, infraorbital step, V2 numbness, trismus.

➡ Blow-out: enophthalmos + diplopia on upgaze + V2 numbness; tear-drop sign on CT. Operate if diplopia > 2 weeks, enophthalmos > 2 mm, or > 50% defect. Paediatric "white-eyed" blow-out = emergency.

➡ Nasal: commonest facial fracture. Drain septal haematoma to prevent saddle-nose.

➡ Mandible is a ring — hunt for a second fracture. Commonest site = angle. Numb lower lip → inferior alveolar nerve injury; protect at ORIF, consent for numbness.

➡ Imaging: fine-cut CT for midface/orbits; OPG for mandible; Waters view = screening only.