1 Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, Freiburg, Germany. johan.woelber@uniklinik-freiburg.de.
2 Department of Operative Dentistry and Periodontology, Center for Dental Medicine, Medical Center - University of Freiburg, Hugstetter Str. 55, Freiburg, Germany.
3 Department of Medical Biometry and Statistics, Medical Center - University of Freiburg, Freiburg, Germany.
4 Institute of Sports and Sports Science, Medical Center - University of Freiburg, Freiburg, Germany.