# Midface Buttresses and Le Fort Fractures > Midfacial buttresses for MBBS Anatomy: vertical and horizontal pillars, Le Fort I II III fracture lines, NOE and ZMC fractures, telecanthus and plating. - Canonical URL: https://prepelephant.com/topics/mbbs/anatomy/midface-buttresses - Exam / course: MBBS · Subject: Anatomy - Publisher: PrepElephant (https://prepelephant.com) — Prepared and reviewed by the PrepElephant Academic Review Team - First published: 2026-10-02 - Last updated: 2026-10-02 - How to cite: "Midface Buttresses and Le Fort Fractures", PrepElephant, https://prepelephant.com/topics/mbbs/anatomy/midface-buttresses ## Direct answer The midface absorbs impact along pillars, not plates: three vertical buttresses — the nasomaxillary along the frontonasal (or nasofrontal) process, the zygomaticomaxillary from the frontozygomatic suture through the infraorbital rim to the maxillary alveolus, and the pterygomaxillary from the pterygoid plates to the maxillary tuberosity — are cross-braced by horizontal struts, the frontal bar, infraorbital rims, zygomatic arches and the alveolus with the palate. Fracture lines follow the weak zones between these pillars, which is exactly what the Le Fort classifications describe: Le Fort I separates the alveolar process, Le Fort II runs a pyramid from nasion through the orbits to the maxilla, and Le Fort III disjoins the whole face from the cranium. Restoring the buttresses, not merely the fragments, is the surgical principle. ## What you must remember - **Vertical buttresses:** nasomaxillary, zygomaticomaxillary (the main load path from the upper teeth to the skull base), and pterygomaxillary — strong bone channels designed to carry masticatory load upward. - **Horizontal buttresses:** frontal bar (supraorbital rims), infraorbital rims, zygomatic arches, and the maxillary alveolus with the hard palate, which also resists transverse collapse. - **Le Fort I:** a horizontal separation through the maxillary sinuses, pyriform apertures and lateral walls of the nose, detaching the palate and alveolus — the "floating palate," classically with a palatal haematoma (Guerin's sign). - **Le Fort II:** a pyramidal fracture from the nasofrontal suture across the medial orbital walls, infraorbital rims and zygomaticomaxillary buttresses, through the lateral walls of the maxilla — the midface moves as a pyramid with the bridge of the nose. - **Le Fort III:** craniofacial disjunction through the frontozygomatic sutures, medial and lateral orbital walls, zygomatic arches and frontonasal junctions — the entire face is mobilised (rhinorrhoea from dural or cribriform involvement is common). - **NOE fracture:** naso-orbito-ethmoid disruption detaches the medial canthal tendon, producing traumatic telecanthus (intercanthal widening beyond the normal, roughly the palpebral width) and a saddle nose. - **ZMC fracture:** the zygomaticomaxillary complex ("tripod") separates at the frontozygomatic suture, infraorbital rim, zygomaticomaxillary buttress and arch — flat cheek, infraorbital nerve numbness, diplopia. ## Reading the fracture pattern on the scan Begin with the question the buttresses answer: which pillars are interrupted? A CT coronal slice through the orbits of a road-traffic victim shows a Le Fort II when the black lines of fracture cross the nasofrontal junction, both infraorbital rims and the lateral maxillary walls in a pyramid — the fragment includes the nose and the maxilla but the zygomas stay attached to the skull. If instead the fractures run through the frontozygomatic sutures and the arches, the zygomas are part of a Le Fort III, and the face is separated at the cranial base; look for CSF rhinorrhoea, malocclusion, and movement of the whole midface on gentle rocking. Pure Le Fort patterns are the exception — most real injuries mix levels on the two sides, so the exam answer "Le Fort II" should always be qualified in practice. Treatment follows the pillars. Plates are placed along the zygomaticomaxillary and nasomaxillary buttresses because these are load-bearing; the thin orbital walls and arch segments need only contour restoration. Occlusion is re-established first (the alveolar horizontal strut), then vertical height is rebuilt along the buttresses — which is why a missed, impacted ZMC fracture presents late with a flat cheek, an enophthalmic eye from an enlarged orbit, and infraorbital dysaesthesia. ## Where candidates slip The classic confusion is Le Fort II versus the ZMC fracture: both involve the infraorbital rim, but Le Fort II crosses the nasofrontal area and both maxillae while the ZMC detaches one zygoma at the frontozygomatic suture and spares the nose. The second slip is forgetting that Le Fort levels mix — the examiner's trap is a patient with a Le Fort II on the right and a ZMC on the left. The third is calling telecanthus "hypertelorism": telecanthus is increased intercanthal distance from medial canthal tendon detachment (NOE), whereas hypertelorism is true widening of the orbits — a distinction maxillofacial surgeons insist on. ## Frequently asked questions ### Which buttresses carry the occlusal load of the upper teeth? Chiefly the zygomaticomaxillary buttresses, assisted by the nasomaxillary pillars — the vertical channels plated first in midface reconstruction. ### What is Guerin's sign? A palatal haematoma near the greater palatine foramen, classically associated with Le Fort I fracture of the maxilla. ### Which fracture produces traumatic telecanthus and why? The naso-orbito-ethmoid (NOE) fracture, because it avulses the medial canthal tendon from the lacrimal crest, letting the intercanthal distance widen. ### How does a Le Fort III fracture differ from Le Fort II? Le Fort III separates the entire midface from the cranium through the frontozygomatic sutures, orbital walls and arches, while Le Fort II leaves the zygomas attached and fractures through the nose and maxillae. ### Why does an old ZMC fracture cause enophthalmos? The fractured orbital floor and walls heal in an outward position, enlarging the orbital volume so the globe falls back and down within an expanded socket.