Irma Thesleff is a developmental biologist recognized for her work on development of mammalian organs. She is best known for studies on tissue interactions regulating tooth formation, and particularly for deciphering the roles of signaling molecules as regulators of development and renewal of teeth. Thesleff was born and grew up in Helsinki, Finland. She graduated as dentist from the Medical Faculty of University of Helsinki (UH) in 1972 and received her PhD in 1975 on studies on the etiology of cleft lip and palate. She was postdoctoral fellow in National Institute of Dental Research, Bethesda 1978-1979. She had an own research laboratory at the Institute of Dentistry of UH 1982-1995, and was Professor in Orthodontics and Pediatric Dentistry in 1990-1995. In 1996 she moved to the Institute of Biotechnology of UH and was Director of the Developmental Biology Program until 2016. She has received several major science awards and is an honorary doctor in 7 universities in Europe and Canada. She has been president of the European Orthodontic Society and the Finnish Society for Developmental Biology. She is an Academician of Science in Finland, member of EMBO, and member of both National Academy of Sciences and National Academy of Medicine.

Research Interests

The aim of research in the Thesleff laboratory has been to understand the mechanisms regulating craniofacial development, in particular the formation and regeneration of teeth and other organs forming from the surface of the embryo such as hairs and glands. The focus is on signaling networks mediating intercellular communication and regulating patterns, numbers, sizes, and shapes of organs. The analysed conserved families of signal molecules include FGF, TGFbeta, Hedgehog, and Wnt as well as Ectodysplasin, a signal specifically required for ectodermal organ development. The main topic of research has been the development of teeth and their renewal from stem cells. The laboratory has developed ex vivo organ culture methods for studying roles of signaling molecules, and in vivo mouse models for elucidating functions of individual genes in development and regeneration. The mouse models also serve as models for human malformations, including congenital dental defects. Their analysis has increased the understanding of the genetic basis and pathogenesis of human syndromes such as ectodermal dysplasia, cleidocranial dysplasia, and tooth agenesis. The research may have clinical implications in the diagnosis, prevention and treatment of congenital defects as well as in the design of regenerative therapies, such as bioengineering of teeth.

Membership Type

International Member

Election Year


Primary Section

Section 22: Cellular and Developmental Biology