Legends
Figure 1. Illustrations show flexible laryngoscopy with nasal pharyngeal oxygen. Laryngeal cleft cannot be detected during nose-open (a), but it become obvious gradually during sustained pharyngeal inflation by doing nose-closure (b).
Figure 2. Serial images of Laryngeal cleft (LC) with different durations of sustained pharyngeal inflation (SPI); nearly normal at SPI of 0 to 1 second (a) and the cleft gradually become obvious at 3 to 5 seconds (b, c).
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