Dr. Dr. Muggenthaler expanded his experience in and knowledge of the field of Aesthetic Surgery through lengthy and repeated periods as a visiting scholar, as well as further training and lectures with the following physicians:

Franz Gsell (Nuremberg)
Udo Fritzemeier (Düsseldorf)
Joram Levy (Garmisch Partenkirchen)
Heinz Bull (Krefeld)
Thomas Hundt (Munich)
Louis Philippe Dombard (Brussels, Belgium)
Brunno Genone (Rome, Italy)
Pelle Ceravolo (Rome, Italy)
Arnaldo Rizzetto Stubel (Padua, Italy)
Giovanni Botti (Salo. Italy)
Dr. Thierry Besins (Paris, France)

Bruce Connell (Los Angeles, USA)
Henry Kawamoto (Beverly Hills, USA)
Robert Flowers (Hawaii, USA)
Robert Singer (San Diego, USA)
Peter Bela Fodor (Beverly Hills, USA)
Garth Fisher (Beverly Hills, USA)
Tom Baker (Miami, USA)
Gregory Hetter (Boca Raton, USA)
Steven Hoefflin (Santa Monica, USA)
Toby Mayer (Beverly Hills, USA)
Richard Ellenbogen (Hollywood, USA)
Andre Camirand (Montreal, Canada)
Hector Gonzalez (Guadalajara, Mexico)
Alejandro Quiroz (Tjuana, Mexico)
Hossam Foda (Alexandria, Egypt)

Jarl Bunaes (Oslo, Norway)

Zein Obagi (Beverly Hills, USA)

Luitgard Wiest (Munich)