Table 1. Incidences of sphenoid pneumatization patterns by classification system.

Hammer's/Radberg's Classification
Paper	Conchal (%)	Presellar (%)	Sellar (%)
Current study, year	0	6	94
Hamberger et al,1961 5	3	11	86
Renn et al, 1975 6	0	20	80
Fujii et al, 1979 7	0	24	76
Banna and Olutola, 1983 8	3	11	86
Ouaknine and Hardy, 1987 9	3	12	85
Sethi and Pillay, 1995 10	0	27	73
Sareen et al, 2005 11	–	25	75
Abuzayed et al, 2009 12	–	20	80
Lazaridis et al, 2010 13	4	28	68
Wang et al, 2010 14	0	2	98
Lu et al, 2011 15	6	29	66
Perondi et al, 2013 16	5	9	86
Vaezi et al, 2015 17	2	24	74
Anusha et al, 2014 18	< 1	7	93
Locatelli 2017 19	1	5	94
Güldner's Classification
Paper	Conchal (%)	Presellar (%)	Sellar (%)	Postsellar (%)
Current study, year	0	6	45	49
Liao et al, 2001 20	4	36	14	46
Kayalioglu et al, 2005 21	2	9	53	36
Zhou 2005 22	3	26	59	12
Hamid et al, 2008 23	2	21	55	22
Cho et al, 2010 24	1	9	47	43
Li et al, 2010 25	2	31	21	47
Güldner et al, 2012 4	< 1	7	57	36
Tomovic et al, 2013 26	2	7	48	43
Wiebracht and Zimmer, 2014 27	0	9	37	54
Halawi et al, 2015 28	0	20	51	29
Rahmati et al, 2016 29	0	2	15	84