title: Maxillary expansion therapy with plates featuring a transverse screw: implications of patient compliance with wear-time and screw activation requirements.
abstract: OBJECTIVE
  The goal of the present work was to determine the influence of screw activation rates and electronically tracked wear times on transverse maxillary expansion with removable orthodontic appliances.
  
  
  METHODS
  In all, 28 patients were included in an open prospective observational study covering approximately 6 months of maxillary transverse expansion. In each of these patients, the maxillary plate appliance used for treatment was fitted with a wear-time sensor to document wear time for the duration of the study. Patients were instructed to activate the transverse expansion screw in their plate appliance by 0.2 mm/week. The resultant gap-width increases were monitored with a caliper over three follow-up appointments scheduled at 2-month intervals.
  
  
  RESULTS
  Largely linear increases in gap width due to screw activation were only noted within the first 4 months of treatment. The mean increases in gap width fell short of the values that were anticipated after calculations. Longer daily wear times were, on average, associated with larger gap widths.
  
  
  CONCLUSIONS
  Treatment can be objectively monitored by referring to wear-time tracking and by measuring increases in gap width, thus, ensuring that the appliance fits well. In this way, the process can be customized to serve individual needs and to better utilize the full potential of therapy.
authors.affiliation: Department of Orthodontics, Center of Dentistry, Oral Medicine, and Maxillofacial Surgery, Eberhard Karls University Tübingen, Osianderstr. 2-8, 72076, Tübingen, Germany, timm_schott@gmx.de.
authors.forename: T C
authors.initials: TC
authors.lastname: Schott
authors.forename: U
authors.initials: U
authors.lastname: Fritz
authors.forename: H
authors.initials: H
authors.lastname: Meyer-Gutknecht
mesh_terms: D000293:Adolescent; D001860:Bone Plates; D001863:Bone Screws; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000175:diagnosis / Q000628:therapy*; D018670:Monitoring, Ambulatory / Q000706:statistics & numerical data; D010155:Palatal Expansion Technique / Q000295:instrumentation* / Q000706:statistics & numerical data*; D010349:Patient Compliance / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D012648:Self Care; D016896:Treatment Outcome