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Table 2 Mean and standard deviation (sd) of the differences between T2 and T1 values for each patient

From: Rapid palatal expansion effects on mandibular transverse dimensions in unilateral posterior crossbite patients: a three-dimensional digital imaging study

   Control group RPE group Diff T2-T1 t test Effect size
  Unit Mean sd Mean sd   p value d value ES
36–46 (occlusal) mm −0.8 0.8 1.1 1.5 1.9 0.00 0.6 Large
36–46 (lingual) mm −0.1 0.4 0.6 1.2 0.7 0.00 0.8 Large
33–43 mm −0.6 0.8 0.4 1.6 1.0 0.01 0.4 Medium
36 angulation ° −3.3 5.2 6.2 5.8 9.5 0.00   
33 angulation ° −6.0 5.0 0.7 5.5 6.7 0.00   
43 angulation ° −2.7 6.6 0.7 7.4 3.4 ns   
46 angulation ° −3.8 5.7 4.3 6.8 8.1 0.00   
31 angulation ° −2.5 4.0 2.0 4.1 4.4 0.00   
41 angulation ° −2.4 3.5 1.8 3.1 4.2 0.00   
Molar angulation (mean) ° −3.5 5.5 5.2 6.3 8.8 0.00 0.6 Large
Canine angulation (mean) ° −4.4 5.8 0.7 6.4 5.1 0.01 0.4 Medium
Incisor angulation (mean) ° −2.4 3.7 1.9 3.6 4.3 0.00 0.5 Medium
  1. Diff. T2-T1 mean differences between RPE and control groups; ns not significant, p > 0.05
  2. d Cohen’s effect size value, ES effect size