First and second year — the floor first, then every step
Read the face as buttresses and name the pattern — Le Fort, zygomaticomaxillary complex, orbital blow-out, naso-orbito-ethmoid, mandible — then say what the fracture does to the orbit and the bite.
Orient first
The face is held by vertical buttresses (nasomaxillary, zygomaticomaxillary, pterygomaxillary) and horizontal ones (frontal bar, orbital rims, palate). Named fracture patterns are combinations of broken buttresses.
Every Le Fort fracture breaks the PTERYGOID PLATES. If the pterygoid plates are intact, it is not a Le Fort fracture.
The orbital floor and medial wall (lamina papyracea) are the thinnest walls; a blow-out breaks them while the rim stays intact.
Acquire the study
Thin-section (≤ 1 mm) CT face on a bone algorithm with CORONAL and SAGITTAL reformats; 3D volume rendering helps the surgeon but is read after the planes.
The coronal reformat is the primary plane for the orbital floor; the sagittal oblique along the optic nerve shows floor defects and muscle position best.
Soft-tissue window of the orbits for the globe, the extraocular muscles and retrobulbar haematoma.
The manoeuvre
Pterygoid plates first, on axial slices at the level of the maxillary sinus floor: intact or fractured.
Le Fort level by the unique fracture of each: I — the lateral nasal aperture / anterior maxillary wall; II — the inferior orbital rim; III — the zygomatic arch and lateral orbital wall. Each side separately; combinations are common.
Zygomaticomaxillary complex: zygomatic arch, lateral orbital wall (zygomaticosphenoid suture), inferior orbital rim/floor and the anterior and posterior maxillary walls. Measure rotation or displacement of the zygoma.
Orbital floor and medial wall on coronal: defect size, herniated fat, and the INFERIOR RECTUS — position and shape (rounded belly suggests loss of support) and whether it passes through the defect.
Naso-orbito-ethmoid: medial orbital rim and the medial canthal tendon insertion fragment; nasal bones and septum.
Mandible as a ring: expect a second fracture (the contralateral angle or condyle) whenever you find one. Check condyles on coronal.
Soft-tissue window: globe contour and volume, lens position, retrobulbar haematoma, intraorbital gas, and the optic canal.
What confirms it
A named pattern is confirmed by its defining fracture: pterygoid plates plus the level-specific fracture for Le Fort; all four zygomatic articulations for a ZMC fracture.
Orbital blow-out: a floor or medial wall defect with herniated fat or muscle and an intact rim.
What licenses you to exclude it
Radiographs cannot exclude a facial fracture in a patient with a significant mechanism — CT is the study.
The classic misread
Calling a Le Fort fracture with intact pterygoid plates.
Missing the second mandibular fracture — the mandible is a ring.
Missing a trapdoor floor fracture in a child: a small, minimally displaced floor fracture with an entrapped inferior rectus and little else.
Calling a globe normal without the soft-tissue window.
Reporting the injury
Classification to use
Le Fort I / II / III per side (combinations and hemi-Le Fort are common).
Zygomaticomaxillary complex (tetrapod) fracture — minimally displaced or displaced/rotated.
Orbital blow-out (pure: rim intact; impure: rim involved).
Naso-orbito-ethmoid: Markowitz type I–III by the medial canthal tendon fragment.
Mandible: by site — symphysis, parasymphysis, body, angle, ramus, condyle (intracapsular / neck / subcondylar), coronoid.
Measurements — and how to take them
Orbital floor defect: anteroposterior and transverse dimension in mm, or the proportion of the floor involved; a large defect (commonly quoted as more than about half the floor, or > 2 cm²) predicts enophthalmos — verify with the surgical team.
Displacement of the zygomatic arch and the frontal sinus anterior-wall fragment in mm.
What to report
The pattern name with every component fracture listed, per side.
Orbital floor/medial wall defect, herniated fat, inferior or medial rectus position and shape.
Involvement of the frontal sinus anterior and posterior walls and the nasofrontal outflow tract.
Teeth in the fracture line and the condyles.
How to report it
CT: "Left zygomaticomaxillary complex fracture involving the zygomatic arch, the zygomaticosphenoid suture, the inferior orbital rim and floor, and the anterior and posterolateral maxillary walls, with inferomedial rotation of the zygoma."
CT: "Right orbital floor blow-out fracture with herniation of extraconal fat; the inferior rectus is rounded and displaced towards the defect."
What not to report
Do not state "entrapment" — entrapment is a clinical diagnosis (restricted gaze); describe the muscle position and its relation to the defect.
Do not name a Le Fort level when the pterygoid plates are intact.
Associated injuries to look for
Globe rupture and retrobulbar haematoma (orbital compartment syndrome), optic canal fracture, cervical spine injury, intracranial injury, and blunt cerebrovascular injury with Le Fort II/III fractures.
What changes management
Retrobulbar haematoma with proptosis and tenting of the posterior globe — an emergency (lateral canthotomy).
Muscle through a floor defect in a child (trapdoor) — urgent surgery.
Each value carries the caveat that keeps it from being misused. Normal limits and diagnostic criteria are kept apart on purpose: a disease cut-off read as a normal range is the more dangerous mistake.
Normal limits
Orbital walls · Integrity of the orbital floor and walls
continuous bony walls; a floor blow-out with inferior-rectus herniation and a trapdoor in a child is the emergency pattern (the lamina-papyracea entry is the medial-wall companion)
A trapdoor fracture in a child can look almost normal on the bone and still incarcerate muscle — look at the muscle and the clinical diplopia.
CT
Lamina papyracea · Integrity of the medial orbital wall
paper-thin but continuous; dehiscence after trauma or endoscopic surgery is the finding, and medial-rectus entrapment is the emergency companion
A congenital dehiscence can exist — look for muscle herniation, haematoma and the clinical diplopia, not a millimetre gap alone.
CT
Diagnostic criteria
Orbit (globe position) · Globe protrusion beyond the interzygomatic line
the anterior globe margin lies within approximately 21–23 mm of the interzygomatic line (texts differ on the exact ceiling)
Axial CT at the level of the lenses: a line is drawn between the anterior tips of the zygomatic processes, and the perpendicular distance to the anterior margin of each globe is measured.
⚠️ Texts genuinely differ on the millimetre — asymmetry over about 2 mm between sides is often the more useful observation. Head tilt and gantry angle shift the line; measure on a properly aligned axial series.
CT
See it on real cases
Direct links to Radiopaedia — the reference article and worked cases with their images. Each opens on Radiopaedia.