Presentation
Trauma to the left side of the face. Attended eye clinic.
Patient Data
Age: 40
Gender: Male
From the case:
Black eyebrow sign
Frontal

Rim of lucency, in keeping with air, projected over the left superior orbit.
The air is curvilinear in a fashion similar to an eyebrow.
No clear orbital fracture.
Case Discussion
The black eyebrow sign is the description given to air in the superior part of the orbit, almost exclusively occuring in the context of an orbital fracture.
Air leaks into the orbital from an adjacent paranasal sinus, for example following an inferior orbital wall fracture, and rises into the superior orbit.
The appearance of this curvilinear lucency is like that of an eyebrow.