BACKGROUND The aim of this questionnaire-based survey was to evaluate information on frequencies, instructions and products relating to oral hygiene (OH) in orthodontic practices. METHODS Using a computer-generated randomization list, 1000 orthodontists were selected and sent a questionnaire. The size and number of inhabitants of the federal states of Germany were considered. The federal states with the highest return rate (Baden-Wuerttemberg [BW], Bavaria [B], Hesse [H], Lower Saxony [LS], Nordrhein-Westphalia [NRW]) were considered and differences between the 16 federal states were divided into North, South, East and Central Germany. RESULTS The response rate of the questionnaires was 52.4%. The majority (53.8%) worked in one practice alone. Most (59.1%) have been orthodontists for 5-25 years. For vestibular multibracket appliances (MBA) in BW, B, H and LS over 90% recommended interdental brushes (IDB). In NRW 91.4% recommend fluoride gel. In B and H more than 80% chose electric toothbrush (ETB), in BW, LS and NRW more than 80% manual toothbrush (MTB). For lingual MBA (LMBA) in BW, H, LS and NRW with approximately 50% each fluoride gel, IDB and MTB were chosen. In B fluoride gel, IDB and ETB. For removable apparatus (RA), five federal states recommended MTB (>80%) and ETB (BW, B, H > 80%; NRW > 70%; LS > 60%). CONCLUSIONS Electric toothbrushes are recommended for the use with all appliances, only with removable appliances manual toothbrushes are favoured. For vestibular MBA it is strongly advised to use IDB additionally.