Funding for this research was provided by:
The Norwegian Directorate of Health, through their support for research at the Norwegian Centers for Oral Health Services and Research.
Received: 13 December 2021
Accepted: 9 March 2022
First Online: 21 March 2022
: The HUNT4 Survey including the HUNT4 Oral Health Study and HUNT70+ was approved by the Norwegian Data Protection Authority. Participation was based on an informed consent. The current study was approved by the Norwegian Regional Committees for Medical and Health Research Ethics (81406/REK midt) and the Norwegian Centre for Research Data (NSD 155523).
: Not applicable.
: The authors declare that they have no competing interests.