Table 8 Maxillary molar movement (Pre-treatment to 24 aligners); Comparison of predicted (virtual) and achieved (actual) tooth movements in all directions. Results of paired T-test or Wilcoxon signed-rank test (N = 18)

Distalization(mm) = + 

Mesialization(mm) = -

0.13 ± 0.58

(-0.16–0.42)

-0.08 ± 0.37

(-0.26–0.10)

-0.45 ± 0.48

(-0.69- -0.21)

-0.60 ± 0.53

(-0.86- -0.34)

0.001^*

0.002^*

-0.58 ± 0.59

(-0.87- -0.28)

-0.52 ± 0.59

(-0.81- -0.23)

0.679

0.81

0.77

Extrusion (mm) = + 

Intrusion (mm) = -

0.48 ± 0.61

(0.17–0.78)

0.49 ± 0.35

(0.32–0.66)

-0.16 ± 0.52

(-0.42–0.10)

-0.03 ± 0.36

(-0.21–0.15)

0.000^*

0.000^*

-0.63 ± 0.49

(-0.88- -0.39)

-0.52 ± 0.28

(-0.66- -0.38)

0.278

0.79

0.58

Buccal (mm) = + 

Lingual (mm) = -

0.41 ± 0.46

(0.18–0.64)

0.40 ± 0.48^#

(0.16–0.64)

0.29 ± 0.61^#

(-0.02–0.59)

0.31 ± 0.54

(0.04–0.57)

0.078^#

0.170^#

-0.12 ± 0.47^#

(-0.35–0.11)

-0.09 ± 0.49^#

(-0.33–0.15)

0.705^#

0.47

0.48

Tip (°)

DCT = + 

4.31 ± 3.09^#

3.72 ± 2.51

1.42 ± 3.12

0.69 ± 2.82

0.000^#,*

0.000^*

-2.89 ± 2.82^#

-3.03 ± 1.87

0.647^#

3.98

3.53

MCT = -

(2.78–5.85)

(2.47–4.97)

(-0.13–2.97)

(-0.70–2.10)

(-4.29- -1.49)

(-3.95- -2.10)

Torque (°)

BCT = + 

-0.14 ± 1.71

-1.00 ± 2.32

0.30 ± 1.97^#

1.34 ± 2.57

0.286^#

0.014^*

0.44 ± 1.80

2.33 ± 3.60^#

0.048^#,*

1.80

4.21

LCT = -

(-0.99–0.71)

(-2.15–0.16)

(-0.68–1.28)

(0.06–2.61)

(-0.46–1.33)

(0.54–4.12)

Rotation (°)

D-in = +

1.74 ± 2.76

0.83 ± 1.59^#

1.76 ± 1.76

0.22 ± 1.86

0.971

0.157^#

0.02 ± 2.10^#

-0.61 ± 1.89

0.557^#

2.04

1.94

M-in = -

(0.37–3.11)

(0.04–1.62)

(0.89–2.64)

(-0.70–1.14)

(-1.02–1.06)

(-1.56–0.33)