(click on images to enlarge)
The PA occipito-mental view provides excellent demonstration of the upper and middle thirds of the face including the orbital margins, frontal sinuses, zygomatic arches and maxillary antra.
Occipito-mental 30 View :
With 30 degrees of caudal angulation, the orbits are demonstrated less well. However, the zygomatic arches and the walls of the maxillary antra are seen clearly.
There are 3 lines for inspecting the OM views:
Line 1:Look for widening of the zygomatico-frontal sutures
Fractures of the superior rim of the orbits“Black-Eyebrow” sign due to orbital emphysema
Opacification / air-fluid level in the frontal sinuses
Line 2:Look for fractures of the superior aspect of the zygomatic arch
Fractures of the inferior rim of the orbitsSoft tissue shadow in the superior maxillary antrum
Fractures of the nasoethmoid bones and medial orbits
Line 3:Look for fractures of the inferior aspect of the zygomatic arch
Fractures of the lateral maxillary antrum
Opacification / air-fluid level in the maxillary sinuses
Fractures of the alveolar ridge
Compare the injured side with the uninjured side.