Pandis 2011.

Study characteristics
Methods	Setting: Corfu, Greece, private practice of study author Design: parallel (2 arms) No. of centres: 1 Study duration: 16 months
Participants	Inclusion criteria: "non‐extraction treatment on both arches, eruption of all mandibular teeth, no spaces in the mandibular arch, mandibular irregularity index greater than 2 mm (canine to canine), and no therapeutic intervention planned involving intermaxillary or other intraoral or extraoral appliances including elastics, maxillary expansion appliances, or headgears before the end of the observation period". Exclusion criteria: not reported Participant sampling: N = 50 selected Group 1 (n = 25): 64% female, 36% male (mean age of 13.4 ± 1.6 years) Group 2 (n = 25): 68% female, 32% male (mean age of 13.2 ± 1.6 years) Sex: 66% female, 34% male Dropouts: none
Interventions	Orthodontic intervention: fixed appliances and auxiliaries Self‐ligating brackets versus conventional brackets
Outcomes	Time to alignment
Notes	Funding source: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Adequate method of randomisation “Fifty patients were randomized to either a conventional or a self‐ligating appliance. The statistical software package was used by the first author, and the user‐written ralloc command was implemented to generate the random allocation sequence. Randomization was accomplished by generating random permuted blocks of variable size (2 and 4), which assured equal patient distribution between the 2 trial arms.”
Allocation concealment (selection bias)	Low risk	Adequate method of allocation concealment “Sequentially numbered, opaque, sealed envelopes were prepared before the trial containing the treatment allocation cards. After patient selection and recording of baseline information, the secretary in the practice was responsible for opening the next envelope in sequence and allocation.”
Blinding of participants and personnel (performance bias) All outcomes	High risk	Not possible to blind participants and personnel due to the different interventions used
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Adequate blinding of assessor “Impressions were taken, plaster models were prepared, and the brackets from second premolar to second premolar were scraped off with a curving knife by the laboratory technician to facilitate blind measurements. Each model had an identification number so that the measurements could be correctly entered into the spreadsheet”
Incomplete outcome data (attrition bias) All outcomes	Low risk	No dropouts
Selective reporting (reporting bias)	Low risk	All outcomes reported
Other bias	Unclear risk	Single centre, private practice