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Neuroradiology Case of the Week

Case 184

Scott Cassar, MD, Farhad Farzanegan, MD,
and Per-Lennart Westesson, MD, PhD, DDS

Clinical Presentation: A 42-year old male with facial trauma after a motor vehicle collision.

Radiological Findings: There are fractures of the orbital walls and zygomatic arches bilaterally. There are communated fractures of the maxillary, ethmoid, and frontal sinuses. There is also a fracture of the posterior frontal endplate with a small adjacent pneumocephalus. Two incisor fragments are seen from a displaced right incisor in the superior nasal cavity/ethmoid region. There is also a left mandibular angle fracture.

Diagnosis: Le Fort III fracture (“craniofascial dysjunction”)

Discussion: René Le Fort described three patterns of midface fractures. These are rarely seen in pure form but remain a convenient way to classify fractures.

• Le Fort I (“floating palate”) is characterized by a horizontal fracture through the maxillary sinuses with separation of the entire palate and maxillary alveolar processes. This fracture type includes the lower nasal septum and inferior aspect of the pterygoid plates.
• Le Fort II (“pyramidal”) is characterized by an inverted ‘V’ type fracture through the medial orbital and lateral maxillary walls. With the apex at the bridge of the nose, the fracture extends in a pyramidal shape through the nasal septum, frontal process of the maxilla, medial wall of the orbit, inferior orbital rim, superior, lateral, and posterior walls of the maxillary antrum, and midportion of the pterygoid plates. The zygomatic arch and lateral orbital walls are spared. This type of fracture can be associated with posterior displacement of the facial bones resulting in a “dish-face” deformity.
• Le Fort III ("craniofascial dysjunction”) is characterized by separation of the entire viscerocranium from the base of the skull. It is a horizontal fracture through the orbits beginning near the nasofrontal suture and extending posterior to involve the nasal septum, medial and lateral orbital walls, zygomatic arches, and base (superior aspect) of the pterygoid plates. This type of fracture also may result in a “dish-face” deformity.

     Our patient had a scant collection of intracranial air adjacent to the frontal sinuses. Injuries associated with a pneumatocele or a single intracranial air bubble have a good prognosis, as do frontobasal lesions. Injuries associated with multiple air bubbles have a poor prognosis. In one study, pneumocephalus was detected in 82% of head injury patients within 6 hours of the accident. The incidence of meningitis occurring with head trauma ranges from 0.2 to 17.8% and increases significantly, up to 50%, in the presence of a skull base fracture or CSF leak.

References:

1. Brant WE, Helms CA. Fundamentals of Diagnostic Radiology, 2nd edition. Philadelphia, Pennsylvania: Lippincott, Williams, & Wilkins; 71-74, 1999.
2. Eftekhar B, Ghodsi M, Nejat F, Ketabchi E, Esmaeeli B. Prophylactic administration of ceftriaxone for the prevention of meningitis after traumatic pneumocephalus: results of a clinical trial. J Neurosurg. 2004 Nov;101(5):757-61. [Medline]
3. Larheim TA, Westesson P-L. Maxillofacial Imaging. Berlin/Heidelberg, Germany: Springer; 219-221, 2006.
4. Steudel WI, Hacker H. Prognosis, incidence and management of acute traumatic intracranial pneumocephalus. A retrospective analysis of 49 cases. Acta Neurochir (Wien). 1986;80(3-4):93-9. [Medline]