title: Treatment effects produced by the Twin-block appliance vs the Forsus Fatigue Resistant Device in growing Class II patients.
abstract: OBJECTIVE
  To compare the dentoskeletal changes produced by the Twin-block appliance (TB) followed by fixed appliances vs the Forsus Fatigue Resistant Device (FRD) in combination with fixed appliances in growing patients having Class II division 1 malocclusion.
  
  
  METHODS
  Twenty-eight Class II patients (19 females and 9 males; mean age, 12.4 years) treated consecutively with the TB followed by fixed appliances were compared with a group of 36 patients (16 females and 20 males; mean age, 12.3 years) treated consecutively with the FRD in combination with fixed appliances and with a sample of 27 subjects having untreated Class II malocclusion (13 females and 14 males; mean age, 12.2 years). Mean observation interval was 2.3 years in all groups. Cephalometric changes were compared among the three groups by means of ANOVA and Tukey's post hoc tests.
  
  
  RESULTS
  The FRD produced a significant restraint of the maxilla compared with the TB and control samples (SNA, -1.1° and -1.8°, respectively). The TB sample exhibited significantly greater mandibular advancement and greater increments in total mandibular length than either the FRD or control groups (SNB, 1.9° and 1.5°, respectively; and Co-Gn, 2.0 mm and 3.4 mm, respectively). The FRD produced a significantly greater amount of proclination of the mandibular incisors than what occurred with the TB or the control samples (2.9° and 5.6°, respectively).
  
  
  CONCLUSIONS
  The TB appliance produced greater skeletal effects in terms of mandibular advancement and growth stimulation while the Forsus caused significant proclination of the mandibular incisors.
authors.affiliation: a   Research Associate, Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy.
authors.forename: Veronica
authors.initials: V
authors.lastname: Giuntini
authors.affiliation: a   Research Associate, Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Vangelisti
authors.affiliation: a   Research Associate, Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy.
authors.forename: Caterina
authors.initials: C
authors.lastname: Masucci
authors.affiliation: b   Associate Professor, Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy.
authors.forename: Efisio
authors.initials: E
authors.lastname: Defraia
authors.affiliation: c   Thomas M. and Doris Graber Endowed Professor of Dentistry, Department of Orthodontics and Pediatric Dentistry, School of Dentistry; Professor of Cell and Developmental Biology, School of Medicine; Research Professor, Center for Human Growth and Development, University of Michigan, Ann Arbor, Michigan; and Private Practice, Ann Arbor, Mich.
authors.forename: James A
authors.initials: JA
authors.lastname: McNamara
authors.affiliation: d   Assistant Professor, Department of Surgery and Translational Medicine, Orthodontics, University of Florence, Florence, Italy; and Thomas M. Graber Visiting Scholar, Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Mich.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Franchi
mesh_terms: D000293:Adolescent; D002508:Cephalometry / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D016382:Orthodontic Appliance Design / Q000295:instrumentation* / Q000379:methods*
keywords: Cephalometrics; Class II malocclusion; Functional jaw orthopedics