On March 26, 2008, Prof Berton A Rahn finally found release from his long and difficult illness.

02 April 2008

Berton Rahn after his presentation at the European Cells and Materials Meeting (ECM) 2003 in Davos. His lecture resulted in a standing ovation and he apparently enjoyed the response.

On March 26, 2008, Prof Berton A Rahn finally found release from his longand difficult illness. We have lost a colleague who dedicated himself to AOresearch in Davos, Switzerland.


Berton Rahn’s father was a journalist for the Davoser Zeitung (thelocal newspaper in Davos). Berton studied dentistry and medicine in Zurich andBerlin. In 1968 he joined the Laboratory for Experimental Surgery in Davos. Thelaboratory had practically begun anew in 1967 after Professor Herbert Fleisch’sbiochemical group moved to Bern. Berton at that time made the brave decision tojoin a group whose future was uncertain as the AO Research Institute at thattime had only enough secure funding for a further two months. Still, he stayedon for the next 37 years.

Bridging of a small fracture gap during direct bone healing. The drilling cone of an osteon is just crossing the gap and is about to connect the left with the right bone fragment.

One of Berton’s areas of interest was the microscopic anatomy (histology) ofbone healing. As a researcher who wanted to get to the bottom of things, hefelt himself at home in the microscopic world of cells and tissues. Hedeveloped the polychrome sequence labeling for newly formed bone which today isused worldwide in bone research. This invention also led to a decrease in thenumber of animals needed for research purposes.


A special interest of Berton’s, and the one which he studied, was oralsurgery. He made important contributions to the development ofcraniomaxillofacial surgery as well as to the important field of dentalimplantology. The correction of deformed and damaged maxillofacial skeletonusing Illizarov’s distraction method took some fundamental steps forward thanksto the clinical application of Berton Rahn’s research.

Polychrome sequence labeling of newly formed bone in the neighborhood of an implant. The fluorescent lines which appear in different colors indicate at which point in time the mineralized bone matrix was deposited.

Another area of his work as a researcher was the chemical stimulation ofbone healing, an area that today in conjunction with the treatment of bone loss(osteoporosis) is receiving a lot of attention. His research was not onlycharacterized by its scientific creativity, but more especially through thesupport he offered to younger researchers.


Berton received his doctorate in dentistry in 1970, followed by one inmedicine in 1973. He qualified as an assistant professor, later becoming anassociate professor at the University of Freiburg in Germany. In addition tohis lecturing responsibilities at the university, he gave lectures on bonehealing, particularly in his specialized area of dentistry, at the AO Coursesin Davos and worldwide. His scientific work could, thanks to his membership ofnumerous research groups in which he served as leader or honorary member,benefit from such a developed international network.

Berton Rahn at the European Cells and Materials Meeting (ECM) 2003 in Davos.

As part of his administrative work, Berton Rahn was vice-director of the AOResearch Institute. He was heavily involved in the building of the AO Center onClavadelerstrasse in Davos which was opened in 1992.


He was a reserved man, but one who in the right moment could surprise withhis jolly and unique style. He was also a family man, one who shared his hobbyof sailing on Lake Constance with his wife Ruth and their children Katja andBeat. Inhis retirement he served as Scientific Advisor to the AO Research Instituteuntil the first symptoms of his illness manifested themselves in his bones, thevery part of the body that he had spent a lifetime studying.

In Berton we have lost a quiet man of depth, and we regret that he could notenjoy the fruits of his labors for a longer period of time. His many scientificcontributions to journals and books will outlast him.


We extend our deepest condolences to his family.


Stephan Perren


Please click here to readthe obituary to Berton Rahn on the ECM website.

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