Devices used for influencing tooth position. Orthodontic appliances may be classified as fixed or removable, active or retaining, and intraoral or extraoral. (Boucher's Clinical Dental Terminology, 4th ed, p19)
January 1985,
Parodontologia e stomatologia (nuova) : organo ufficiale dell'ARPA italiana, della Societa italiana Jonoforesi stomatologica e della Accademia ligustica di stomatologia,