Due to blow to eye and floor is offers least resistance
Clincal features include enophthalmos and diplopia (upward gaze)
Nearly 25% are associated with ocular injury
Soft tissue in the superior margin of maxillary sinus
Trapdoor bone fragment into sinus, often on ethmoidal side
Orbital emphysema (black eye brow sign) is a string indicator of blow out fracture either from orbital floor or medial wall.
Images:
Orbital emphysema:
Coronal CT:
Floor of orbit fixation:
