Funding for this research was provided by:
University of Helsinki including Helsinki University Central Hospital
Article History
Received: 23 February 2021
Accepted: 18 April 2021
First Online: 28 April 2021
Declarations
:
: The internal board of the Head and Neck Center of the Helsinki University Hospital, Helsinki, Finland, approved the study protocol (HUS/356/2017).
: Not applicable.
: Not applicable.
: The authors declare no competing interests.