Funding for this research was provided by:
Science and Technology Planning Project of Shenzhen Municipality (JCYJ20160428173808742)
Sanming Project of Medicine in Shenzhen (SZSM201612078)
Foundation of Shenzhen Health and Family Planning Commission (SZXJ2018085)
Received: 21 October 2019
Accepted: 7 February 2020
First Online: 21 February 2020
Ethics approval and consent to participate
: This study was approved by the Anatomy Department of the Medical College of Shenzhen University.
: Not applicable.
: The authors declare that they have no competing interests.