Table 1.

Pneumatisation grades in all analysed planes

Pneumatisation	Plane
	MP (n = 100)	SPCP-R (n = 100)	SPCP-L (n = 100)
I	3 (3%)	2 (2%)	2 (2%)
II	6 (6%)	12 (12%)	11 (11%)
III	41 (41%)	38 (38%)	36 (36%)
IVA	38 (38%)	36 (36%)	41 (41%)
IVB	12 (12%)	12 (12%)	10 (10%)

I – conchal, II – presellar, III – sellar, IVA – postsellar – no pneumatisation of the dorsum sellae (DS) and posterior clinoid process (PCP), IVB – postsellar – pneumatisation of the DS and PCP, MP – midline plane, SPCP-R – sagittal posterior clinoid plane right, SPCP-L – sagittal posterior clinoid plane left