Table 2. .

Detailed Search Strategy for All Electronic Databases, Until the Third Week of April 2019

Database	Search Strategy	Hits
General sources
PubMed http://www.ncbi.nlm.nih.gov/pubmed	(orthodon*[All Fields] OR “fixed orthodontic"[All Fields] OR bracket*[All Fields] OR “orthodontic force"[All Fields] OR “mechanical force"[All Fields]) AND (“tooth movement"[All Fields] OR “orthodontic movement"[All Fields] OR “orthodontic anchorage"[All Fields]) AND (“recurrence"[MeSH Terms] OR “recurrence"[All Fields] OR “relapse"[All Fields])	290
Cochrane Central Register of Controlled Trials https://www.cochranelibrary.com/advanced-search	Title Abstract Keyword: ((orthodon* OR “fixed orthodontic” OR bracket* OR “orthodontic force” OR “mechanical force”) AND (“tooth movement” OR “orthodontic movement” OR “orthodontic anchorage”) AND (relapse))	8
Scopus https://www.scopus.com/search/form.uri?display=advanced	TITLE-ABS-KEY (orthodon* OR “fixed orthodontic” OR bracket* OR “orthodontic force” OR “mechanical force”) AND (“tooth movement” OR “orthodontic movement” OR “orthodontic anchorage”) AND (relapse)	937
Web of Science http://apps.webofknowledge.com/	TS=((orthodon* OR “fixed orthodontic” OR bracket* OR “orthodontic force” OR “mechanical force”) AND (“tooth movement” OR “orthodontic movement” OR “orthodontic anchorage”) AND (relapse)) Timespan: All years Databases: All databases Search language: Auto	293
Embase (via OVID) http://ovidsp.tx.ovid.com/sp-3.33.0b/ovidweb.cgi	(((orthodon*.mp OR exp orthodontics/ or exp orthodontic device/) OR fixed orthodontic.mp OR (bracket*.mp OR exp orthodontic bracket/) OR orthodontic force.mp OR mechanical force.mp)) AND ((tooth movement.mp OR (orthodontic movement.mp OR exp orthodontic tooth movement/) OR (orthodontic anchorage.mp OR exp orthodontic anchorage/)) AND ((relapse OR exp relapse/)))	820
Gray literature sources
ClinicalTrials.gov http://clinicaltrials.gov/	(orthodontic OR orthodontics) AND (tooth movement) AND (relapse)	0
ProQuest Dissertations and Theses Global http://search.proquest.com/dissertations	(orthodon* OR “fixed orthodontic” OR bracket* OR “orthodontic force” OR “mechanical force”) AND (“tooth movement” OR “orthodontic movement” OR “orthodontic anchorage”) AND (relapse)	5