Table 4: Results of the intergroup comparison of the maxillary and mandibular dental arches dimensions in the initial stage of treatment (T1) (independent t or Mann-Whitney tests).

Variables (mm) Group 1
Damon
(N=21)
Group 2
Conventional
(N=24)
P
Mean (Median) S.D. (i.r.) Mean (Median) S.D. (i.r.)
Mx IC 34.70 (35.24) 1.97 (1.87) 35.03 (35.25) 2.01 (3.46) 0.494 ¥
Mx I1PM 35.52 1.96 36.02 2.28 0.443
Mx I2PM 40.87 2.33 41.23 2.51 0.625
Mx IM 45.04 2.75 44.94 2.52 0.894
Mx AL 68.26 3.59 67.92 4.14 0.776
Md IC 26.15 1.52 26.63 1.23 0.246
Md I1PM 30.24 2.07 30.19 1.72 0.931
Md I2PM 35.19 2.42 35.15 2.32 0.956
Md IM 39.99 2.72 39.24 2.39 0.333
Md AL 57.85 2.65 57.20 3.50 0.496

Mx=Maxillary; Md=mandibular; IC=Intercanine distance; I1PM=inter first premolar distance; I2PM=inter second premolar distance; IM=intermolar distance; AL=arch length.
Mean and Standard Deviation (S.D.), when using independent parametric t test; Median and interquartile range (i.r.), when using the non-parametric Mann-Whitney test.
€ independent t test
¥ non-parametric Mann-Whitney test