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)

P value

Index

Male

Female

All samples

206

0.962 ± 0.184

0.096

 Child

52

0.902 ± 0.204

0.216

 Teenager

91

0.976 ± 0.192

0.548

 Adult

63

0.979 ± 0.161

< 0.001**

 Class I

103

0.978 ± 0.219

0.094

 Class II

66

0.967 ± 0.189

0.356

 Class III

37

0.912 ± 0.222

0.920

(b)

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*

 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

 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)

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*

 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

 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**