Table 1.

Means, SDs of the value of forehead protrusion, and mean differences between sexes (a), between growth phases (b), and that for dentoskeletal classifications (c)

(a)	Number			Mean ± SD of forehead protrusion (cm)			P value
Index	Male	Female		Male		Female
All samples	206	208		0.995 ± 0.210		0.962 ± 0.184	0.096
Age
Child	52	42		0.854 ± 0.168		0.902 ± 0.204	0.216
Teenager	91	75		0.994 ± 0.192		0.976 ± 0.192	0.548
Adult	63	91		1.111 ± 0.196		0.979 ± 0.161	< 0.001**
Dentoskeletal Classification
Class I	103	107		1.022 ± 0.219		0.978 ± 0.219	0.094
Class II	66	62		1.000 ± 0.210		0.967 ± 0.189	0.356
Class III	37	39		0.907 ± 0.161		0.912 ± 0.222	0.920
(b)	Number			Mean ± SD of forehead protrusion (cm)			P value
Index	Child	Teenager	Adult	Child	Teenager	Adult
All samples	94	166	154	0.876 ± 0.185	0.986 ± 0.192	1.033 ± 0.188	0.001*
Sex
Male	52	91	63	0.854 ± 0.168	0.994 ± 0.192	1.111 ± 0.196	< 0.001**
Female	42	75	91	0.902 ± 0.204	0.976 ± 0.192	0.979 ± 0.161	0.058
Dentoskeletal Classification
Class I	29	94	87	0.873 ± 0.182	0.986 ± 0.192	1.057 ± 0.176	< 0.001**
Class II	30	50	48	0.808 ± 0.133	1.020 ± 0.195	1.055 ± 0.177	< 0.001**
Class III	35	22	19	0.936 ± 0.209	0.905 ± 0.169	0.867 ± 0.192	0.455
(c)	Number			Mean ± SD of forehead protrusion (cm)			P value
Index	Class I	Class II	Class III	Class I	Class II	Class III
All samples	210	128	76	0.999 ± 0.193	0.984 ± 0.199	0.910 ± 0.193	0.003*
Sex
Male	103	66	37	1.022 ± 0.219	1.000 ± 0.210	0.907 ± 0.161	0.016*
Female	107	62	39	0.978 ± 0.162	0.967 ± 0.189	0.912 ± 0.184	0.154
Age
Child	29	30	35	0.873 ± 0.182	0.808 ± 0.133	0.936 ± 0.209	0.020*
Teenager	94	50	22	0.986 ± 0.192	1.020 ± 0.195	0.905 ± 0.169	0.063
Adult	87	48	19	1.057 ± 0.176	1.055 ± 0.177	0.867 ± 0.191	<0.001**

SD standard deviation

*Statistical significance (P < 0.05) as determined by the Independent-Samples T-Test and analysis of variance

**Highly statistically significant (P < 0.001)