Agger nasi is pneumatization of lacrimal bone.
For frontal sinus , u require 0.6 mm axial cuts with Sagittal and coronal reconstructions in 3D mode.
Frontal recess is like hourglass appearance.
As long as we see the floor of frontal sinus , it is sinus. When floor not seen, it is frontal recess.
Supra orbital cell is lateral and posterior to frontal sinus.
Good suction like liposuction unit suction increases the life of microdebrider three times.
PJ wormald suggested minimum size of 4 mm of frontal sinus opening but ideal is 8mm.
Balloon sinuplasty may not create this much size.