Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.|Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.|Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.|Department of Oral and Maxillofacial Diseases, Helsinki University Hospital, University of Helsinki, Helsinki, Finland.|Department of Mathematics and Systems Analysis, Aalto University, Espoo, Finland.|Developmental Biology Program, Institute of Biotechnology, University of Helsinki, Helsinki, Finland.