Metterlein T, Dintenfelder A, Plank C, Graf B, Roth G. Rev Bras Anestesiol. 2017 Mar - Apr;67(2):166-171
Random assignment of 52 adult patients to different supraglottic devices, from: Laryngeal Tube, LMA, i-gel, LMA Unique, LMA Supreme and Aura-once. After successful ventilation, device positioning was examined to assess glottic opening. Glottic view ranged from 40% for Laryngeal Tube to 90%, with i-gel recording 70%.
Link to abstract.