From: Low-level laser therapy effectiveness in reducing initial orthodontic archwire placement pain in premolars extraction cases: a single-blind, placebo-controlled, randomized clinical trial
N
Sex
Initial LIIa (mm)
Age (years)
Male
Female
Mean
SD
Laser group
13
2
11
8.91
1.57
18.53
2.9
Placebo group
4
9
10.8
2.29
21.61
2.63
Signifigance
0.352b
0.022c
0.009c
Total sample
26
6
20
9.86
2.15
20.07
3.13