Table 2 Search strategy for electronic databases

1°

PubMed, Cochrane Library, Embase, Scopus, Web of Science, and OpenGrey

Maxillary expansion

PubMed (MEDLINE) (n = 4150)

Cochrane Library (n = 400)

Embase (n = 3289)

Scopus (n = 3518)

Web of Science (n = 4340)

OpenGrey (n = 5)

Total: n = 15,702

2°

PubMed

("palatal expansion technique"[MeSH Terms] OR ("palatal"[All Fields] AND "expansion"[All Fields] AND "technique"[All Fields]) OR "palatal expansion technique"[All Fields] OR ("maxillary"[All Fields] AND "expansion"[All Fields]) OR "maxillary expansion"[All Fields]) AND (("child"[MeSH Terms] OR "child"[All Fields]) OR ("adolescent"[MeSH Terms] OR "adolescent"[All Fields]))

PubMed (MEDLINE) (n = 2202)

Cochrane Library, Embase, Scopus, Web of Science, and OpenGrey

["palatal expansion technique" OR (palatal expansion technique)] OR ["maxillary expansion" OR (maxillary expansion)] AND (child OR adolescent)

Cochrane Library (n = 388)

Embase (n = 1841)

Scopus (n = 2370)

Web of Science (n = 4000)

OpenGrey (n = 2)

Total: n = 10,803

Total records identified: 26,505