Table 5 Relationship between frontal sinus width and forehead protrusion of males (a), adults (b), dentoskeletal classification I (c), and whose most convex position of the forehead in the lower 1/3 part (d)

(a) Male

204

0.937 ± 0.291

0.995 ± 0.211

0.013*

 Child

52

0.825 ± 0.245

0.854 ± 0.168

0.655

 Teenager

89

0.907 ± 0.254

0.995 ± 0.194

0.589

 Adult

63

1.071 ± 0.326

1.111 ± 0.196

0.353

 Class I

101

0.967 ± 0.300

1.024 ± 0.220

0.026*

 Class II

66

0.876 ± 0.270

1.000 ± 0.210

0.159

 Class III

37

0.963 ± 0.291

0.907 ± 0.161

0.841

(b) Adult

152

0.880 ± 0.301

1.033 ± 0.189

<0.001**

Sex

 Male

63

1.070 ± 0.326

1.111 ± 0.196

0.353

 Female

89

0.977 ± 0.163

0.745 ± 0.191

0.318

Dentoskeletal classification

 Class I

85

0.886 ± 0.323

1.058 ± 0.178

<0.001*

 Class II

48

0.870 ± 0.269

1.055 ± 0.177

0.157

 Class III

19

0.877 ± 0.292

0.866 ± 0.191

0.545

(c) Class I

204

0.849 ± 0.287

1.002 ± 0.194

0.009*

Sex

 Male

101

0.967 ± 0.300

1.023 ± 0.220

0.026*

 Female

103

0.734 ± 0.220

0.981 ± 0.163

0.828

Age

 Child

29

0.751 ± 0.283

0.873 ± 0.182

0.738

 Teenager

90

0.845 ± 0.245

0.991 ± 0.192

0.457

 Adult

85

0.886 ± 0.323

1.058 ± 0.178

<0.001**

(d) In the lower 1/3

204

0.917 ± 0.293

0.974 ± 0.204

0.002*

Gender

 Male

143

0.975 ± 0.306

1.006 ± 0.210

0.027*

 Female

61

0.781 ± 0.203

0.899 ± 0.166

0.950

Age

 Child

39

0.837 ± 0.255

0.844 ± 0.158

0.635

 Teenager

78

0.886 ± 0.264

0.954 ± 0.184

0.804

 Adult

87

0.980 ± 0.321

1.050 ± 0.206

0.004*

Dentoskeletal classification

 Class I

100

0.949 ± 0.306

1.020 ± 0.205

0.009*

 Class II

61

0.869 ± 0.271

0.982 ± 0.193

0.112

 Class III

43

0.910 ± 0.285

0.856 ± 0.160

0.625