Funding for this research was provided by:
The Education Fund, Finland
Article History
Received: 13 December 2017
Accepted: 22 October 2018
First Online: 15 November 2018
Ethics approval
: The primary casts were prepared for studies performed in 1990’s. At that time, no ethics committee approval was required. These casts prepared then were for this study further transformed to ultrasound permeable casts and there was no further interaction with humans or animals.
: Not applicable.
: The authors declare that they have no competing interests.
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