Table 4.

GRADE assessment for quality of evidence

Patient or population: patients with orthodontic treatment Settings: RCT and CCT Intervention: vibrational stimulus
Outcomes	Illustrative comparative risks (95% CI)		Relative effect(95% CI)	No of Participants(studies)	Quality of the evidence(GRADE)	Comments
	Assumed risk	Corresponding risk
	Control	Vibrational stimulus
rate of OTM in alignment	See comment	See comment	Not estimable	187(3 studies)	⊕⊝⊝⊝very lowa,b,c	vibrational stimulus did not increase tooth movement in alignment
rate of OTM in canine retraction	See comment	See comment	Not estimable	60(2 studies)	⊕⊝⊝⊝very lowb,d,e	vibrational stimulus increased the rate of canine retraction

^aUnclear risk in random sequence generation, allocation concealment, blinding of participants, incomplete reporting and other bias

^bThe procedure of orthodontic treatment and vibrational stimulus and follow-up durations varied

^cOnly three studies with limited sample size (n = 187) were included

^dHigh risk of bias in randomization, blinding and other bias

^eOnly two studies with limited sample size (n = 60) were included