This projection allows the orbits to be checked for their
equality of size, which is important in patients with proptosis. The floor of
the hypophyseal fossa can be seen through the nasal cavity and this should be
looked at closely if a pituitary tumour is suspected. Check the supraorbital
fissure and the greater and lesser wings of sphenoid for any abnormality. Watch
for vault fractures in the frontal region and for blowout fractures through the
floor of the orbit. The nasal cavity, the medial wall of the maxillary antrum
and the ethmoid air cells are well seen in this projection.
