Difficult airways for advanced mask design

We read the editorial by Shih-Yi Lee et al. on “Prospective view for mask design” with a great interest (1). In the article, the authors have proposed a new mask design for difficult mask ventilation (DMV). We would like to suggest them take the risk factors of difficult intubation (DI) into consideration into the design of novel masks, because both DMV and DI possibly cause difficult airways, though the risk factors between DMV and DI are different in some ways (2-5).