The 6th Ratón Pérez Tooth Collection Campaign, which the National Centre for Research on Human Evolution (CENIEH) has been organising in Burgos since 2014 thanks to the sponsorship of the Obra Social "la Caixa" and the Caja de Burgos Foundation, will count in this sixth edition with the collaboration of institutions from nine autonomous regions: Andalusia, Asturias, Balearic Islands, Cantabria, Castilla y León, Catalonia, Extremadura, Galicia and Madrid.

Once again this year, young and old will be able to donate their milk teeth in exchange for a gift and a certificate as an assistant to the tooth fairy and the CENIEH Dental Anthropology Group, during the celebration of the European Researchers' Night, on Friday 27 September.

On that date, institutions from all over Spain will be in charge of collecting the dental pieces: CENIEH, from 18.00 to 22.00h, in Burgos; ADEMA, from 18:00 to 20:00h, in Palma de Mallorca; the University of Alcalá, from 17:00 to 20.30h, in Alcalá de Henares; the University of Cantabria, from 18. 30 to 22:00h, in Santander; the University of Cordoba, from 19:00 to 24:00h in Cordoba; the University of Extremadura, from 18:00 to 21:00h, in Cáceres; the University of Jaén, from 17:00 to 22:00h, in Jaén; the University of Oviedo, from 18:00 to 20:00h, in Avilés, and the Casita Museo del Ratón Pérez, from 17:00 to 20:30h, in Madrid.

The Alba Synchrotron in Barcelona already collected teeth on 29 June, coinciding with the Open Day of this Singular Scientific and Technical Infrastructure (ICTS), and will collaborate with the CENIEH again next year. For its part, the CSIC delegation in Galicia will carry out its collection on 30 November, during the Feira das Industrias Culturais Galegas (CULTURGAL) held in Pontevedra.

The aim of these Campaigns, coordinated by Dr. Marina Martínez de Pinillos González together with researchers Cecilia García Campos and Ana Pantoja Pérez, is to gather one of the most important collections of dental pieces in the world for studies of both human evolution and forensics.

"Thanks to the donors, we will be able to obtain very useful data for our research, such as the age at which the tooth fell out, the sex of the individual, their place of birth and that of their parents and grandparents, among others," says Dr Martínez de Pinillos.