1 Institute of Health Data Analytics and Statistics, College of Public Health, National Taiwan University, Taipei, Taiwan; Department of Dentistry, National Taiwan University Hospital, National Taiwan University, Taipei, Taiwan.
2 Department of Orthodontics and Dentofacial Orthopedics, Dental School/Medical Faculty, University of Bern, Bern, Switzerland. Electronic address: [email protected].
3 Midwifery Research and Education Unit, Hannover Medical School, Hannover, Germany.