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)

Index	Number	Mean ± SD (cm)		P
		frontal sinus width	forehead protrusion
(a) Male	204	0.937 ± 0.291	0.995 ± 0.211	0.013*
Age
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
Dentoskeletal classification
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

The Number in all categories refers to cases in which the maximum anterior-posterior diameter of the frontal sinus can be traced and measured in the lateral cephalometric radiograph

*Statistical significance (P < 0.05) as determined by Pearson’s two-variable analysis

**Highly statistically significant (P < 0.001)