The Two by Four appliance: a nationwide cross-sectional survey.

Aim: The aim of the study was to investigate how widespread is the use of the 2 x 4 appliance among Italian general dentists and specialists in orthodontics, as well as the type of treatment employed and length of use.

Materials And Methods: We conducted a nationwide cross-sectional survey from July 14, 2016 to January 12, 2017 using an online questionnaire of 8 multiple choice questions, created by the SurveyMonkey® Company, on a population of Italian dentists and specialists in orthodontics affiliated with the Italian Society of Paediatric Dentistry (SIOI). This was made to assess how many clinicians knew and used this device in their clinical practice.