Table 1: Overview of systematic reviews investigating oral appliances for sleep apnea.

Systematic review	Databases searched (years)	Inclusion criteria	Studies eligible for inclusion
McDaid et al (NICE review), 2009 (1)	Medline Embase Cochrane Up to November 2006	RCTs Primary outcome: measures of sleepiness	29 studies (systematic review compares CPAP to other technologies; 6 RCTs comparing CPAP to MAS were identified)
Lim et al (Cochrane review), 2006 (2) updated to June 2007	Medline Cochrane Up to June 2007	RCTs Patients with OSA (AHI >5) >16 years Primary outcome: daytime sleepiness Secondary outcomes: quality of life, cognitive function, side effects, oxygen desaturation indices, 1-year mortality, patient preference	17 studies
Ferguson et al. 2006 (4)	PubMed Up to July 2004	Adult patients English Peer-reviewed	15 randomized trials
Hoekema et al. 2004 (5)	Medline (1966-2002) Embase (1989-2002) Cochrane (1800-2002)	Patients with OSA (AHI >5) >21 years Intervention group treated with MRA Control group treated with any conservative, surgical or non-invasive treatment (including no treatment or placebo) Primary outcome AHI during a full-night sleep study*	16 (13 included in meta-analyses)
ECRI 2002 (3)	Medline (up to Aug 2001) Embase (up to Aug 2001) Cochrane (up to Aug 2001) ECRI databases (up to Aug 2001)	Patients with OSA Pre- and post-test studies Parallel and single-arm trials FDA approved devices	5 randomized trials

AHI, apnea hypopnea index; ESS, Epworth Sleepiness Scale; MAS, mandibular advancement splints