Funding for this research was provided by:
Fondation Nestlé (NA)
Received: 21 August 2018
Accepted: 16 May 2019
First Online: 31 May 2019
Ethics approval and consent to participate
: The study was conducted in accordance with the 1957 Declaration of Helsinki, and the protocol was approved by the Ethics Committee of the Canton of Bern, Switzerland (Ref. no. 256/2015).
: Not applicable.
: The research fund of the Department of Oto-Rhino-Laryngology, Head and Neck Surgery received a grant from Nestlé Health Science (Vevey, Switzerland), to partially support the research activity concerning this study. Nestlé Health Science was not involved at any phase of the study, and has had no insights in the studies outcomes or the manuscript prior to publication.
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