Table 2: Statistics on Standard drill v Long drill mean screw angles.

 

n

X ± weeks

95% CI

P value (Standard vs. Long)

Mean screw angle-Standard drill

25

5.8 ± 1.7

2.3-9.3

 

Mean screw angle-Long drill

34

2.1 ± 0.8

0.4-3.8

 

Mean screw angle-difference

 

3.7 ± 1.7

 0.2-­7.2

 0.037a

Mean difference corrected for gender

 

3.6 ± 1.7

0.1-7.0

 0.042c

 Mean difference corrected for age

 

2.0 ± 1.89

1.9-5.8

0.31c

Mean difference corrected for side

 

3.6 ± 1.7

-0.1-7.1

 0.043c

Max screw angle-Standard drill

25

7.2 ± 1.7

 3.7-10.7

 

Max screw angle-Long drill

34

3.7 ± 0.9

1.9-5.5

 

Max screw angle-difference

 

5.2 ± 0.9

 3.4-­7.0

 0.053a

Max difference corrected for gender

 

3.4 ± 1.7

0.2-6.9

 0.060c

Max difference corrected for age

 

1.6 ± 1.9

2.2-5.6

0.40c

Max difference corrected for side

 

3.4 ± 1.8

0.2-6.9

 0.062c

aby T test; cby linear regression

X: Mean