title: Self-ligating fully customized lingual appliance and chair-time reduction: a typodont study followed by a randomized clinical trial.
abstract: In this study, we tested the hypothesis that self-ligation can reduce the chair time necessary for inserting and removing the archwire in a fully customized, multi-bracket, orthodontic, lingual appliance. A permuted-block, randomized trial design was employed to treat seven patients, each with Incognito(®) lingual appliances and Harmony(®) self-ligating lingual appliances. Three operators (a third year resident in orthodontics, an orthodontic specialist, and an experienced lingual orthodontist) were instructed, and they were allowed to familiarize themselves with two typodonts. Next, the operators were asked to insert and remove a.014 NiTi customized archwire for each patient, and they were timed. The time required for removing and inserting archwires decreased proportionally with operator experience: it was shorter with self-ligating appliances (114.82±18.06 seconds versus 595.83±289.09 seconds, P < 0.001) and when testing the typodonts' performances (480.61±285.74 seconds versus 518.65±296.97 seconds, P < 0.001). However, differences between operators were smaller when using typodonts (31.77±21.19 seconds versus 43.87±27.06 seconds, P < 0.001) and with self-ligation (15.17±9.29 seconds versus 45.37±25.44 seconds, P < 0.001). In vivo performance improved after typodont training, allowing for difference reductions between operators. Lingual self-ligation appears to require less hands-on ability and training of the orthodontist, for reduction of chair time.
authors.affiliation: * Department of Orthodontics, School of Dentistry, University of Brescia, Italy.
authors.forename: Domenico
authors.initials: D
authors.lastname: Dalessandri
authors.forename: Elena
authors.initials: E
authors.lastname: Lazzaroni
authors.forename: Marco
authors.initials: M
authors.lastname: Migliorati
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Piancino
authors.forename: Ingrid
authors.initials: I
authors.lastname: Tonni
authors.forename: Stefano
authors.initials: S
authors.lastname: Bonetti
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D008026:Ligation / Q000295:instrumentation; D008297:Male; D008875:Middle Aged; D003765:Models, Dental; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013997:Time Factors; D055815:Young Adult