Table 4 Subgroup analysis of each polymorphism based on ethnicity, age group, and control group

 Caucasian (2)

1.18 (0.66, 2.11), 0.58, 73, 0.05

1.49 (0.58, 3.85), 0.41, 55, 0.13

1.02 (0.53, 1.97), 0.95, 53, 0.14

1.16 (0.53, 1.97), 0.95, 0.53, 0.14

1.33 (0.77, 2.29), 0.30, 6, 0.30

 Asian (2)

0.96 (0.84, 1.09), 0.52, 0, 0.98

0.97 (0.73, 1.29), 0.81, 0, 0.99

1.07 (0.80, 1.43), 0.64, 0, 0.96

1.02 (0.78, 1.33), 0.91, 0, 0.97

0.92 (0.77, 1.10), 0.35, 0, 0.96

 Children (4)

0.98 (0.87, 1.10), 0.68, 25, 0.26

1.03 (0.80, 1.33), 0.82, 4, 0.37

1.00 (0.80, 1.25), 0.99, 4, 0.44

0.99 (0.81, 1.23), 0.96, 7, 0.36

0.95 (0.80, 1.13), 0.58, 0, 0.45

 Caries free (4)

0.98 (0.87, 1.10), 0.68, 25, 0.26

1.03 (0.80, 1.33), 0.82, 4, 0.37

1.00 (0.80, 1.25), 0.99, 4, 0.44

0.99 (0.81, 1.23), 0.96, 7, 0.36

0.95 (0.80, 1.13), 0.58, 0, 0.45

 Caucasian (4)

0.86 (0.56, 1.32), 0.49, 80, 0.002

0.67 (0.18, 2.45), 0.54, 82, 0.0009

1.13 (0.80, 1.59), 0.48, 0, 0.45

1.18 (0.86, 1.62), 0.31, 35, 0.20

0.76 (0.34, 1.72), 0.51, 84, 0.0003

 Mixed (1)

1.23 (0.79,1.91), 0.36

1.62 (0.64, 4.09), 0.31

1.73 (0.77, 3.90), 0.18

1.69 (0.78, 3.68), 0.18

1.09 (0.53, 2.23), 0.82

 Children (4)

0.82 (0.57, 1.18), 0.28, 67, 0.03

0.58 (0.19, 1.82), 0.35, 74, 0.01

1.30 (0.84, 2.01), 0.26, 3, 0.36

1.16 (0.76, 1.75), 0.49, 42, 0.16

0.66 (0.37, 1.17), 0.15, 70, 0.02

 Caries free (3)

0.79 (0.39, 1.63), 0.53, 86, 0.0006

0.42 (0.03, 5.41), 0.51, 88, 0.0003

1.00 (0.66, 1.51), 1.00, 0, 0.44

0.74 (0.27, 2.02), 0.56, 55, 0.11

0.66 (0.15, 2.95), 0.59, 89, < 0.0001

 Low caries (2)

1.03 (0.83, 1.29), 0.78, 0, 0.37

1.30 (0.79, 2.14), 0.30, 0, 0.59

1.57 (0.97, 2.53), 0.07, 0, 0.76

1.45 (0.92, 2.28), 0.11, 0, 0.62

0.90 (0.66, 1.23), 0.51, 0, 0.57

 Caucasian (3)

1.43 (1.10, 1.85), 0.007, 45, 0.16

2.49 (1.19, 5.24), 0.02, 0, 0.85

1.74 (0.81, 3.74), 0.16, 0, 0.98

2.16 (1.05, 4.45), 0.04, 0, 0.85

1.41 (1.04, 1.91), 0.03, 45, 0.16

 Mixed (1)

1.11 (0.57, 2.15), 0.77

0.27 (0.03, 2.47), 0.24

0.14 (0.01, 1.46), 0.10

0.24 (0.03, 2.17), 0.20

1.43 (0.67, 3.05), 0.36

 Children (2)

1.46 (0.92, 2.32), 0.11, 22, 0.26

0.61 (0.13, 2.93), 0.54, 38, 0.20

0.35 (0.07, 1.74), 0.20, 35, 0.22

0.54 (0.11, 2.56), 0.44, 37, 0.21

1.71 (1.02, 2.85), 0.04, 0, 0.53

 Caries free (2)

1.62 (1.21, 2.17), 0.001, 0, 0.59

2.499 (1.19, 5.24), 0.02, 0, 0.85

1.74 (0.81, 3.74), 0.16, 0, 0.98

2.16 (1.05, 4.45), 0.04, 0, 0.85

1.67 (1.17, 2.39), 0.0050, 0.58

 Low caries (2)

0.97 (0.63, 1.50), 0.89, 0, 0.61

0.27 (0.03, 2.47), 0.24

0.14 (0.01, 1.46), 0.10

0.24 (0.03, 2.17), 0.20

1.05 (0.66, 1.68), 0.83, 0, 0.32

Polymorphism, (number of studies)

T vs. C

TT vs. CC

CT vs. CC

CT + TT vs. CC

TT vs. CC + CT

OR (95%CI), P-value, I² (%), P_h

OR (95%CI), P-value, I² (%), P_h

OR (95%CI), P-value, I² (%), P_h

OR (95%CI), P-value, I² (%), P_h

OR (95%CI), P-value, I² (%), P_h

 Asian (2)

0.92 (0.24, 3.58), 0.91, 78, 0.03

5.22 (0.25, 108.96), 0.29

0.89 (0.23, 3.48), 0.87, 77, 0.04

0.90 (0.23, 3.63), 0.89, 78, 0.03

2.90 (0.92, 9.12), 0.07, 0, 0.69

 Children (2)

0.92 (0.24, 3.58), 0.91, 78, 0.03

5.22 (0.25, 108.96), 0.29

0.89 (0.23, 3.48), 0.87, 77, 0.04

0.90 (0.23, 3.63), 0.89, 78, 0.03

2.90 (0.92, 9.12), 0.07, 0, 0.69

 Caucasian (2)

0.95 (0.35, 2.55), 0.92, 69, 0.07

1.42 (0.54, 3.76), 0.48, 17, 0.27

2.80 (0.93, 8.43), 0.07, 0, 0.38

1.63 (0.67, 4.01), 0.28, 0, 0.42

0.73 (0.19, 2.87), 0.66, 67, 0.08

 Mixed (1)

0.99 (0.53, 1.86), 0.98

1.03 (0.28, 3.75), 0.96

0.95 (0.40, 2.25), 0.91

0.98 (0.46, 2.07), 0.95

1.04 (0.29, 3.75), 0.95

 Children (2)

1.21 (0.77,1.91), 0.42, 0, 0.37

1.54 (0.61, 3.92), 0.36, 0, 0.37

1.24 (0.61, 2.49), 0.56, 5, 0.31

1.24 (0.66, 2.33), 0.50, 24, 0.25

1.26 (0.56, 2.83), 0.25

 Caries free (2)

0.95 (0.35, 2.55), 0.92, 69, 0.07

1.42 (0.54, 3.76), 0.48, 17, 0.27

2.80 (0.93, 8.43), 0.07, 0, 0.38

1.63 (0.67, 4.01), 0.28, 0, 0.42

0.73 (0.19, 2.87), 0.66, 67, 0.08

 Low caries (1)

0.99 (0.53, 1.86), 0.98

1.03 (0.28, 3.75), 0.96

0.95 (0.40, 2.25), 0.91

0.98 (0.46, 2.07), 0.95

1.04 (0.29, 3.75), 0.95

 Caucasian (2)

2.87 (0.35, 23.23), 0.32, 95, < 0.0001

5.12 (0.09, 278.85), 0.42, 93, 0.0002

1.00 (0.12, 8.23), 1.00, 0.81, 0.02

2.03 (0.10, 42.44), 0.65, 92, 0.0004

6.17 (0.41, 92.05), 0.19, 91, 0.001

 Asian (1)

1.38 (0.25, 7.75), 0.71

0.93 (0.04, 23.52), 0.97

0.33 (0.01, 12.82), 0.56

0.89 (0.04, 22.53), 0.95

1.89 (0.30, 11.85), 0.50

 Mixed (1)

1.87 (1.06, 3.30), 0.03

3.82 (1.19, 12.21), 0.02

5.11 (1.33, 19.72), 0.02

4.03 (1.27, 12.75), 0.02

1.39 (0.69, 2.80), 0.35

 Children (3)

2.48 (0.76, 8.05), 0.13, 90, < 0.0001

4.69 (0.55, 40.16), 0.16, 86, 0.0007

1.72 (0.37, 7.92), 0.48, 75, 0.02

2.65 (0.49, 14.35), 0.26, 84, 0.002

3.55 (0.72, 17.60), 0.12, 87, 0.0004

 Adults (1)

1.38 (0.25, 7.75), 0.71

0.93 (0.04, 23.52), 0.97

0.33 (0.01, 12.82), 0.56

0.89 (0.04, 22.53), 0.95

1.89 (0.30, 11.58), 0.50

 Caries free (2)

2.87 (0.35, 23.23), 0.32, 95, < 0.0001

5.12 (0.09, 278.85), 0.42, 93, 0.0002

1.00 (0.12, 8.23), 1.00, 0.81, 0.02

2.03 (0.10, 42.44), 0.65, 92, 0.0004

6.17 (0.41, 92.05), 0.19, 91, 0.001

 Low caries (2)

1.82 (1.06, 3.11), 0.03, 0, 0.74

3.28 (1.14, 9.43), 0.03, 0, 0.42

3.42 (1.04, 11.28), 0.04, 47, 0.17

3.43 (1.21, 9.75), 0.02, 0, 0.39

1.44 (0.75, 2.77), 0.27, 0, 0.76

 Caucasian (1)

1.08 (0.63, 1.85), 0.78

1.04 (0.43, 2.51), 0.94

1.27 (0.49,3.30), 0.63

1.14 (0.56, 2.29), 0.72

1.00 (0.42, 2.39), 1.00

 Adults (1)

1.08 (0.63, 1.85), 0.78

1.04 (0.43, 2.51), 0.94

1.27 (0.49,3.30), 0.63

1.14 (0.56, 2.29), 0.72

1.00 (0.42, 2.39), 1.00

 Caucasian (2)

1.25 (0.77, 2.03), 0.37, 30, 0.23

1.83 (0.47, 7.06), 0.38, 40, 0.20

1.20 (0.65, 2.22), 0.56, 0, 0.54

1.25 (0.69, 2.27), 0.46, 0, 0.35

1.67 (0.44, 6.34), 0.45, 31, 0.23

 Children (3)

0.59 (0.16, 2.11), 0.41, 82, 0.003

1.83 (0.47, 7.06), 0.38, 40, 0.20

0.55 (0.13, 2.25), 0.40, 80, 0.006

0.59 (0.15, 2.31), 0.45, 79, 0.008

1.67 (0.44, 6.34), 0.45, 31, 0.23