Miles 2012.

Methods	Allocation: Randomised controlled trial Setting: Private practice, Pennsylvania, United States of America Sample size calculation: Calculated as 90% at 0.05 level to detect 20% faster alignment and reduction in irregularity Dropouts: 2 out of 66 participants did not complete the trial. The authors did not mention the reasons
Participants	66 participants with fixed orthodontic appliance 0.018 inch bracket slot system Age 11 to 15 years old Non‐extraction treatment plan in the lower arch No impacted or unerupted teeth Participants living close to the orthodontic practice
Interventions	One Intervention group and one control group. Initial alignment of the lower anterior teeth using 0.018 x 0.025‐inch bracket slot system brackets and 0.014‐inch nickel titanium arch wire for 10 weeks. Intervention: The vibration appliance (Tooth Masseuse), which provided a vibrational frequency of 11 Hz and 0.06N (˜6.1 g), was applied immediately after the initial arch wire was placed, to accelerate the alignment of the mandibular teeth. The participants were instructed to use the vibrational appliance daily for 20 minutes each session. Control: treated with initial arch wire only.
Outcomes	Primary outcome The amount of tooth alignment measured by the reduction in the irregularity using Little's Irregularity Index at 0, 5 , 8 and 10 weeks of starting treatment. Secondary outcome Pain and discomfort levels using visual analogue system during teeth alignment at 5 different time points (immediately after initial braces placement, 6 to 8 hours after fitting the braces, 1 day after, 3 days after and 7 days after)
Notes	Several attempts to contact authors with no response (invalid email address)
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomly allocated in blocks of 6 as mentioned in page 214 "randomly assigned in blocks of six" No mention of how the randomisation was created
Allocation concealment (selection bias)	Unclear risk	No mention of allocation method
Blinding of participants and personnel (performance bias) All outcomes	High risk	Clinician and investigator blinded but not the participants as mentioned on page 216: "The clinician was blinded to the study participants at all appointments. Identification numbers were assigned to the models prior to the measurements to ensure blinding". When the participant is not blinded, it can influence the visual analogue scale (VAS) scoring for discomfort, which is scored by the participant.
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Outcome assessors were blinded during assessment, as mentioned on page 216: "Identification numbers were assigned to the models prior to the measurements to ensure blinding"
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	No mention of how missing data from participants who dropped out were dealt with, e.g. intention‐to‐treat analysis
Selective reporting (reporting bias)	Low risk	All planned outcomes reported, although neither P value for statistical testing of data nor the confidence intervals were reported. No protocol published
Other bias	Unclear risk	Pain may have occurred in other teeth in the lower or upper arch, which could have resulted in bias. The study appeared to be free of other forms of bias