Table 7. Risk of bias assessment according to RoB 2 tool.

RoB 2: Cochrane risk-of-bias tool for randomized trials

Study	Bias arising from the randomization process	Bias due to deviations from intended interventions		Bias due to missing outcome data	Bias in measurement of the outcome	Bias in selection of the reported results
		Effect of assignment to interventions	Effect of adhering to interventions
Abdelhameed and Refai, 2018 [34]	Low risk: "assignment of patients and the sides of interventions were performed as follows: computer-generated random numbers were done using Microsoft Office Excel 2013 sheet". (Page 2181)	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "no information" on whether the important non-protocol interventions were balanced across intervention groups	Low risk: "during the study, there was one dropout patient in Group C. Also, there were some missing appointments which were all recorded as follows: Group (A), two missing patient appointments at the 4th, and 10th weeks. Group (B), one missing patient appointment in the 10th week. Group (C), no missing patient appointments but there was one dropout patient as mentioned previously". (Page 2182). "Nearly all" the outcome data is available.	Some concerns: the method of measuring the outcome is appropriate but the outcome assessor was not blind for the assignment of each intervention. "Data for the evaluation of each intervention were collected by direct intraoral measurements using a digital intraoral caliper". (Page 2182)	Low risk: the numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements
Farid et al., 2019 [36]	Low risk: "random numbers were generated on a computer using Microsoft Office Excel 2007 sheet by a person who was not involved in the clinical trial (MA). The concealed allocation was performed by using a set of random numbers placed in sealed opaque envelopes. Each patient picked up a number that would represent the intervention side (laser + corticotomy) performed either on the RT side or the LT side and thus the opposing number would be the comparator side (corticotomy only). By calling FS who was accessible to the random table, the intervention which will be performed either on the LT or the RT side was revealed. At the time of intervention, the subject was allowed to choose one of the envelopes to detect her number in the randomization sequence and thus detect which was the intervention side". (Page 276)	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "no information" on whether the important non-protocol interventions were balanced across intervention groups	Low risk: "all patients had successfully completed the four months duration of the study except for 3 dropout patients who did not continue the follow-up visits at the beginning of leveling and alignment phase of the orthodontic treatment that was substituted by another 3 patients who were fulfilling the same inclusion criteria of the study." "During the course of the study, there were no losses in the pre-intervention or in the final records derived from the dental models. No dropout visits were recorded regarding the monthly impression visits. As for laser visits, nine patients missed their appointments in the third and fourth months that was recorded by date and was replaced by another consecutive visit." (Page 279)	Low risk: the method of measuring the outcome is appropriate and the outcome assessor was blind for the assignment of each intervention. "Three-dimensional digital models were obtained by scanning the sequential stone models using a surface laser scanner. The incremental rate of canine retraction was then measured using a 3-shape program". (Page 278). "Landmark identification was done through two blinded assessors (NA and AN) and an average of their measurements was considered for the statistical analysis". (Page 279)	Low risk: The numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements
Yousif et al., 2019 [16]	Some concerns: the method used for randomization was not reported. “A randomized split-mouth clinical multi-operator study was performed on 30 orthodontic patients". "Subjects were randomized equally into three canine retraction groups"	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "no information" on whether the important non-protocol interventions were balanced across intervention groups	Low risk: "no information" on whether the outcome available for all, or nearly all, participants, and probably the result was not biased by missing outcome data. "Study was carried out to overcome attrition bias (patient dropout) due to poor oral hygiene or bad patient compliances" (Page 3223)	Some concerns: the method of measuring the outcome is appropriate but the outcome assessor was not blind for the assignment of each intervention. "The distance between the distal surface of the canine and the mesial surface of the second premolar was recorded directly in patient’s mouth every week using a caliper with 0.01-mm scale". (Page 3226)	Low risk: the numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements
Sivarajan et al., 2019 [38]	Low risk: "randomized block sampling was carried out using RANDOM.ORG online software to allocate participants into three intervention groups on a 1:1:1 basis". (Page 185)	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "No information" on whether the important non-protocol interventions were balanced across intervention groups	Low risk: "thirty subjects were enrolled into the study between September 2014 and March 2016 with data collection complete by March 2017 and no dropouts". (Page 186). "All" the outcome data is available	Low risk: "the distance from the central point of the canine bracket to the superior margin of the mini implant (maxilla) and the inferior margin of the mini implant (mandible) and the distance from the canine cusp tip to the mesiobuccal groove of the first molar was clinically measured using electric digital calipers (accurate to 0.01 mm)". (Page 185). "The outcome measurements were also blinded". (Page 185). The method of measuring the outcome is appropriate and the outcome assessor was blind for the assignment of intervention	Low risk: the numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements
Asif et al., 2020 [35]	Some concerns: the method used for randomization was not reported. "This study was a single-center, single-blind, prospective randomized split-mouth clinical trial". (Page 580)	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "No information" on whether the important non-protocol interventions were balanced across intervention groups	Some concerns: 6 patients (2 from MOP 4-weeks Group and 4 from MOP 8-weeks Group) were dropouts. The reasons are illustrated in Figure 4 (consort flow diagram). (Page 583)	Some concerns: "the distance of canine movement was recorded every 4 weeks with digital calipers accurate to 0.01 mm, for 12 weeks". (Page 581). “Two observers (orthodontic postgraduate students) were blinded to the frequency of MOP while analyzing the BV/TV ratio using CT analyzer software as CBCT files were labeled by random numbers". (Page 581). The method of measuring the outcome is appropriate, but there is "no information" on whether the outcome assessor was blind to the assignment of each intervention	Low risk: the numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements
Jaiswal et al., 2021 [37]	Low risk: "random numbers were generated in the permuted random block size of 2 using the Research Randomizer software (Research Randomizer, Version 4, Urbaniak GC and Plous S) by the investigator AJ. The numbers were concealed in opaque envelopes and kept in a box. Each patient was then asked to pick a sealed envelope to assign the second MOP to either the right or left side, executed separately without any role of primary clinical investigators, shuffled every time before picking". (Page 417)	Some concerns: blinding cannot be performed. There is "no information" on whether any deviations arose because of the trial context	Some concerns: blinding cannot be performed. And "No information" on whether the important non-protocol interventions were balanced across intervention groups	Low risk: "one patient was excluded after intervention owing to miniscrew implant failure". (Page 418). "Nearly all" outcome data is available	Low risk: “the models were scanned with Maestro 3D scanner (MDS 400, AGE solutions S.r.l., Pisa, Italy) with an accuracy of 0.01 mm to obtain digital models. These digital models were imported in Dolphin 3D software (Version 11.9, Patterson Inc., Chatsworth, CA) and the baseline (T0) model was superimposed on T30, T60, T90, and T180 day models with medial 2/3rd of third rugae as the reference point". (Page 417). “However, the extracted data was coded during collection and analysis to ensure blinding". (Page 417). The method of measuring the outcome is appropriate and the outcome assessor was blind to the assignment of each intervention	Low risk: the numerical result being assessed has not probably been selected, based on the results, from multiple eligible outcome measurements within the outcome domain and analyses of the data. The eligible reported results for the outcome corresponded to the intended outcome measurements