Maxillary fractures (Le Fort classification)
The Le Fort classification provides a simple way to describe complex combined injuries. In clinical practice, injuries are often asymmetric (e.g., Le Fort II on one side and Le Fort III on the other) and may occur without involving the tooth-bearing alveolar process.
- Le Fort I: The horizontal fracture line extends above the piriform aperture, below the base of the zygomatic bone, and towards the pterygoid process of the sphenoid bone. It is often bilateral, and fragments may remain undisplaced.
- Le Fort II: Pyramidal fracture. The inferior orbital rims and the lateral walls of the maxillary sinuses are injured. On direct radiographs, the nasal bone fracture characteristic of this type may be missed.
- Le Fort III (suprazygomatic): Results in complete craniofacial dissociation — separation of the midface from the cranial base, which visually lengthens the face. The line runs through the nasal bones, orbital walls, and zygomatic arches (zygomatic arches).
In combined type II and III fractures, blood often accumulates in the maxillary sinus, resulting in hemosinus with a visible fluid level or total opacification.
Zygomatic complex and orbital trauma
The zygomatic bone forms the orbital margins and the walls of the maxillary sinus. Its typical fractures are localized at four points: frontozygomatic and temporozygomatic sutures, infraorbital margin, and the lateral wall of the sinus. An isolated fracture of the zygomatic arch (from a direct lateral blow) usually has three fracture points. In severe comminuted trauma, CT often reveals emphysema in the soft tissues of the cheek.
Orbital blow-out fractures (blow-out fractures) occur with blunt trauma to the anterior orbit. A sharp spike in intraocular pressure "blows out" the thin walls—the orbital floor or the lamina papyracea of the ethmoid bone (lamina papyracea). Importantly, the orbital rim itself remains intact.
Clinically, the injury manifests as globe retraction (enophthalmos) and diplopia due to entrapment of the extraocular muscles, most commonly the inferior rectus (inferior rectus). Coronal CT slices clearly show a herniation-like prolapse of orbital tissues downward into the maxillary sinus cavity. If the injury goes unrecognized, malunion will lead to persistent double vision due to fibrosis.
Mandibular fractures
The mandible most frequently fractures in typical anatomically weak zones:
- Coronoid process (processus coronoideus)
- Condylar neck (collum mandibulae)
- Angle of the mandible (angulus mandibulae)
- Body and symphysis
A critical rule of maxillofacial traumatology: in approximately 50% of cases, a fracture of the mandibular body is accompanied by an occult fracture on the opposite side (typically, the contralateral condylar neck breaks). Orthopantomography (OPTG), supplemented by oblique and anteroposterior projections, is best suited for basic diagnostics. Intraoral radiographs are indicated for injuries in the symphysis region.
Principles of diagnostic imaging
Standard radiography (Waters view or occipitomental projection) is performed in a delayed manner, as severe edema may obscure fracture details. Zygomatic arch fractures are best visualized on "soft" submentovertex views.
The imaging method of choice for severe combined facial skeleton trauma is computed tomography (CT or CBCT) with thin slices and 3D reconstruction. When analyzing tomograms, the physician must evaluate:
- Degree of rotation and displacement of bone fragments.
- Integrity of the globes.
- Potential optic nerve compression.
- State of the cribriform plate of the ethmoid bone (lamina cribrosa).
- Presence of radiopaque foreign bodies.
Temporomandibular joint (TMJ)
The articular apparatus is also affected in trauma. The mandibular condyle is separated from the articular fossa by a fibrocartilaginous disc (discus articularis). Trauma at an early age can lead to bifid condyle, while severe impacts in adults can lead to internal derangements, such as disc displacement relative to the condylar head.
Disc displacement without reduction often causes severe pain and jaw locking. If conservative treatment fails or surgery is planned, the patient is referred for MRI. This is the only method that reliably visualizes the position of the articular disc with the mouth fully open and closed.
Le Fort fracture levels (from bottom to top): I — horizontal above the piriform aperture, II — pyramidal (involving orbital floors and sinuses), III — suprazygomatic (complete craniofacial dissociation and visual lengthening of the face).
Class and exam questions
Are maxillary fractures always symmetric and typical?
No, in practice they are often asymmetric (e.g., Le Fort II on one side and Le Fort III on the other). Impact from sharp objects can result in complex comminuted fractures.
How do orbital blow-out fractures manifest clinically and radiologically?
Enophthalmos and diplopia are characteristic due to muscle entrapment (most commonly the inferior rectus). CT reveals prolapse of orbital contents into the maxillary sinus with intact orbital rims.
Which imaging method is optimal for diagnosing mandibular injuries?
The baseline method is orthopantomography (OPTG), supplemented by oblique and anteroposterior projections. Intraoral radiographs are taken when anterior tooth trauma is suspected.
What else to study on this topic
- Internal derangements and disc displacement of the temporomandibular joint (TMJ)
- Developmental anomalies: hemifacial microsomia and Hurler syndrome
- Myofascial pain syndrome and its radiographic appearance
- Mandibular condylar hyperplasia and radionuclide imaging
- Application of 3D modeling in reconstructive maxillofacial surgery
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