Table 1.

Electronic database search strategies.

Electronic Database	Search Strategy
MEDLINE via PubMed (searched up to 11/15/2018) search strategy:	(orofacial myotherapy OR oral myotherapy OR tongue-muscle training OR oropharyngeal exercise* OR swallow* exercise* OR myofascial exercise* OR myofunctional therapy OR tongue exercise* OR tongue training OR genioglossus exercise* OR pharyngeal exercise* OR breathing exercise* OR inspiratory muscle OR expiratory muscle OR respiratory exercise OR speech therapy OR musical OR didgeridoo) AND (apnea OR apnea OR OSA OR snoring OR sleep-disordered breathing)
	Language: limit to English
	Species: limit to Humans
	Article types: limit to Clinical trial, meta-analysis, Randomized controlled trial, Review, Systematic reviews
The Web of Science (searched up to 11/20/2018)	TOPIC: (tongue-muscle training OR oropharyngeal exercise* OR swallow* exercise* OR myofascial exercise* OR myofunctional therapy OR tongue exercise* OR tongue training OR genioglossus exercise* OR pharyngeal exercise* OR speech therapy OR respiratory muscle training OR inspiratory muscle training OR expiratory muscle training OR musical OR didgeridoo) AND TOPIC: (apnea OR apnea OR snoring OR sleep-disordered breathing)
	Filter: Language = English
	Filter: Article (166), review (22), proceedings paper (10), Book chapter (1)
The Cochrane Library (searched up to 11/21/2018)	#1. (tongue-muscle training OR oropharyngeal exercise* OR swallow* exercise* OR myofascial exercise* OR myofunctional therapy OR tongue exercise* OR tongue training OR genioglossus exercise* OR pharyngeal exercise* OR speech therapy OR respiratory muscle training OR inspiratory muscle training OR expiratory muscle training OR musical OR didgeridoo)
	#2. (apnea OR apnea OR snoring OR sleep-disordered breathing)
	#3. #1 and #2
EMBASE (searched on up to 11/20/2018)	1. 'tongue muscle' AND training OR (oropharyngeal AND exercise*) OR (swallow* AND exercise*) OR (myofascial AND exercise*) OR (myofunctional AND therapy) OR (genioglossus AND exercise*) OR (pharyngeal AND exercise*) OR (speech AND therapy) OR (respiratory AND muscle AND training) OR (inspiratory AND muscle AND training) OR (expiratory AND muscle AND training) OR didgeridoo
	2. apnea OR apnea
	3. #1 and #2 combine
	4. #3 AND ('article'/it OR 'article in press'/it OR 'conference paper'/it OR 'conference review'/it OR 'review'/it) AND [english]/lim
	Filters: English
	Publication types= 'article'/it OR 'article in press'/it OR 'conference paper'/it OR 'conference review'/it OR 'review'/it

OSA = obstructive sleep apnea