Table 4 Discriminant validity of the ISF:8 and ISF:16: overall and subscale scores for children with no cavities or malocclusion (Group 1); with cavities and without malocclusion (Group 2); and with malocclusion and without cavities (Group 3) (n = 136)

mean ± SD

median

mean ± SD

median

mean ± SD

median

p-value*

Total scale

   ISF:8

5.66 ± 3.73

5.00

8.50 ± 4.61

8.00

6.93 ± 4.23

6.00

<0.001

   ISF:16

9.63 ± 7.78

7.00

12.94 ± 5.55

13.00

13.98 ± 8.4

12.00

<0.001

Subscale

Oral Symptoms

   ISF:8

2.07 ± 1.33

2.00

3.09 ± 1.24

3.00

2.15 ± 1.60

2.00

<0.001

   ISF:16

3.43 ± 2.45

3.00

5.18 ± 2.02

5.50

4.28 ± 2.50

4.00

<0.001

Functional limitations

   ISF:8

1.80 ± 1.86

1.00

2.59 ± 1.87

2.50

1.74 ± 1.58

2.00

0.06

   ISF:16

2.70 ± 2.52

2.00

3.68 ± 1.99

3.00

3.78 ± 2.40

4.00

0.01

Emotional well-being

   ISF:8

1.02 ± 1.43

0.00

1.47 ± 1.46

1.00

1.13 ± 1.37

1.00

0.22

   ISF:16

2.16 ± 2,36

2.00

2.68 ± 2.40

2.00

3.15 ± 2.54

2.50

0.07

Social well-being

   ISF:8

0.77 ± 0.99

0.00

1.35 ± 1.39

1.00

1.91 ± 1.50

2.00

<0.001

   ISF:16

1.34 ± 2.20

0.00

1.41 ± 1.37

1.00

2.76 ± 2.56

2.00

<0.001