Deviation of the anterior part of the nasal septum can easily be seen with a hand-held speculum and a headlight. More-posterior deviations are better seen on nasal endoscopy. CT scanning for the diagnosis of sinus disease may give clear evidence of bony deflections of the posterior septum and may show their relationship to the osteomeatal complex into which the sinus is drained. Assessment of the nasal airway may be made as described above with the use of a polished spatula, or by formal rhinomanometry. Most ENT specialists do not regard rhinomanometry as necessary for the diagnosis of nasal obstruction due to a deviated septum.