Table 2 Summary of the significant Chi² statistics on the relationship between participants’ orthodontic information sources and gender, educational level, and monthly income

Gender (P = 0.018; Cramér’s V = 0.28; 95% CI [0.09, 0.45])

 Male

%, 95% CI

29.17 (17.82, 35.01)

20.83 (12.85, 28.66)

22.92 (35.58, 54.99)

27.08 (2.4, 12.7)**

Adjusted Residual

− 0.31

− 0.01

2.36

− 2.62

 Female

%, 95% CI

26.42 (20.3, 38.03)

20.75 (12.91, 28.75)

45.28 (14.72, 31.11)*

7.55 (18.42, 35.75)

Adjusted Residual

0.31

0.01

− 2.36

2.62

Education level (P = 0.004; Cramér’s V = 0.31; 95% CI [0.12, 0.47])

 Low

%, 95% CI

33.33 (24.14, 42.53)

20.83 (12.91, 28.75)

12.5 (6.05, 18.95)

33.33 (24.14, 42.53)*

Adjusted Residual

0.7

0.01

− 2.61

2.47

 Average

%, 95% CI

20 (12.2, 27.8)

20 (12.2, 27.8)

46.15 (36.43, 55.88)**

13.85 (7.11, 20.58)

Adjusted Residual

− 2.33

− 0.26

3.26

− 1.08

 High

%, 95% CI

58.33 (48.72, 67.95)*

25 (16.56, 33.44)

16.67 (9.4, 23.93)

0

Adjusted Residual

2.52

0.38

− 1.39

− 1.66

Monthly income (P = 0.004; Cramér’s V = 0.31; 95% CI [0.12, 0.47])

 Low

%, 95% CI

11.11 (4.98, 17.24)

25.93 (17.38, 34.47)

22.22 (14.11, 30.33)

40.74 (31.16, 50.32)***

Adjusted Residual

− 2.25

0.77

− 1.59

3.88

 Average

%, 95% CI

33.33 (24.14, 42.53)

16.67 (9.4, 23.93)

40.74 (31.16, 50.32)

9.26 (3.61, 14.91)

Adjusted Residual

1.35

− 1.1

1.38

− 2.18

 High

%, 95% CI

35 (25.7, 44.3)

25 (16.56, 33.44)

35 (25.7, 44.3)

5 (0.75, 9.25)

Adjusted Residual

0.82

0.52

0.04

− 1.58