It is with great sadness that we inform you that Professor Berton Rahn passed away on 26 March 2008 following a long illness. Berton will be missed by all of us at eCM as a respected scientist whose histological work on bone remodelling is world renowned. His influence throughout the formative years of the AO Research Institute and the AO Foundation as a whole will always be remembered.

	Berton Rahn, was born in Zürich on January 11th 1939. He grew up in Schaffhausen and completed his Matura in 1958. He first studied Dentistry in Zürich until 1964 and then Medicine in Berlin until 1968. He added to his double doctor degrees in 1985 by becoming a Professor through the University of Freiburg, Germany. Berton first joined the AO at the Laboratory for Experimental Surgery (LECD - the former ARI), then located on Oberstrasse. At this time, only AO Research existed in Davos. He became the Vice-Director of the Institute already in 1975. He later helped design the present AO Centre, which we moved into in 1991.
	Berton is famous world-wide for his morphological based bone histology. In the early 70's he introduced the fluorochrome marker system for showing bone growth in vivo. Later this year eCM will publish a tutorial on his work with fluorochromes in bone remodelling. This fundamental work (which was originally published in German) is well known and used, but rarely referenced to the original work of Berton.
Berton always worked closely with the maxillofacial community with distraction osteogenesis work and worked with general bone healing histology, tissue-implant interactions, inorganic bone substitutes and just before retiring in 2003 on the influence of growth factors on bone regeneration. A main interest and speciality of Berton was all fields of microscopy. He consulted for ARI on this area (and on his long-time experience on bone histology) from his retirement up until earlier this year, even during periods between treatment for his cancer, ironically of bone.
	Berton was an active member of many societies and helped place AO Research on the world map in this way. He was one of the original council members of the European Society for Biomaterials (ESB), helped organise their meeting here in 1984 and then organised the meeting here in 1993, where he introduced the idea of the last minute poster, which many conferences use now. He was on the ESB awards council for over 10 years and was the vice president of the society for 8 years. This is why he was chosen as an honorary member of the ESB in 2003. The numerous other societies he joined, ranged from histology, to dentistry to biomedical engineering.

Berton was an author on well over 150 papers and has had several dozens of students pass through his hands always picking up at least an interest in histology and microscopy. I am proud to have been one of those students who joined him in the old Laboratory for Experimental Surgery and came with him to the new AO Centre, we are in today. I have received many emails of condolences from these students and colleagues. I am also proud to have had such a good turn out to the meeting we organised in honour of his retirement in June 2003 (eCM IV: Bone Tissue Engineering), where many of his colleagues came especially to honour him.
	Berton is missed as a mentor, work colleague and good friend. R. Geoff Richards

Obituary by Professor Stephan Perren.

Some messages

"Apart from the importance of his contributions to science and to all who
worked with him at AO, his unique sense of humour and deep humanity made
being in his company a great pleasure. I, like many others I'm sure, will
miss him greatly."
Dr. Iolo ap Gwynn, Aberystwyth, Wales.

"I learnt a lot from Berton in Davos, thereafter and even after his retirement. I will miss him, not only as previous supervisor but also a friend in Bone Research"
Prof. Qin Ling, Hong Kong.

"We will all miss him. He was a very kind person who I know liked to help people."
Prof Charlie Archer Cardiff, Wales.

"I will remember Berton as a very competent, helpful and humorous person who always had an open ear and a brilliant idea to solve problems with his hugh experience."
Heide Kloeppel, ex student, Germany.

"For all of us, this is a great loss, the urge of growing into Berton's big scientific and
human footsteps, and the reminder that we all should be aware of not being immortal." Prof.i.R.Dr.Hanns PLENK, Vienna, Austria.

"This is a great loss not only for his family, but also for the entire scientific community. For the ESB this is indeed the loss of another founder member, who will remain in my memory as a man so full of enthusiasm and humanity. We will miss him greatly."
Prof. James Kirkpatrick, Mainz, Germany.

"I can count myself lucky to have shared his excellent advice, academic interest and dry humour during my years in Davos."
Dr Stephen Ferguson, Bern, Switzerland.

"He was truly a wonderful person"
Jim Green, Synthes, Philadelphia, USA.

" I was always very much impressed by his personality, his humanity and his high scientific level."
Dr. Wolfhart Rieger, Metoxit, Thayngen, Switzerland.

"I will always remember him as such an open, friendly and helpful person and always so enthusiastic about science and research based on careful and quantitative investigations."
Prof Marcus Textor, Zurich, Switzerland

" I have great memories of Berton, from my Phd days when I was able to use polyfluorochrome labels thanks to his advice and help. A great loss to the bone and tooth community."
Professor Allen Goodship, London, England.

"He taught me everything I needed to know on bright-light and fluorescent microscopy. He created history with his fluorochrome labelling. Since my first arrival until departure his presence was vital and inseparable to the institute’s history. This is how I will remember him, an honourable, quiet, and knowledgeable man"
Dr Zibi Gugala, Houston, USA

"His contribution to our scientific community and to the ESB will remain for ever in our memory."
Dr. Luigi Ambrosio, Naples, Italy

Prof B. Rahn was my supervisor while I stayed in the reseearch institute. I had nev er forgotten his kindness during my stay.
Keizo MORIKAWA, Aichi, Japan

I am very sad because with him passed away also the golden age of biomaterials an biomechanichs research, the pioneering times, the new technologies incoming, dreams and expectations. Our community missed a sincere friend and an outstanding scientist.
Prof. Paolo Tranquilli Leali, ESB Past President
Orthopedics Clinic, Catholic University, Rome, Italy

Last modified October 21, 2011

Publisher: AO Foundation, Davos, Switzerland