title: Thin-plate spline analysis of mandibular shape changes induced by functional appliances in Class II malocclusion : A long-term evaluation.
abstract: OBJECTIVE
  The purpose of this work was to evaluate the long-term morphological mandibular changes induced by functional treatment of Class II malocclusion with mandibular retrusion.
  
  
  METHODS
  Forty patients (20 females, 20 males) with Class II malocclusion consecutively treated with either a Bionator or an Activator followed by fixed appliances were compared with a control group of 40 subjects (19 females, 21 males) with untreated Class II malocclusion. Lateral cephalograms were available at the start of treatment (T1, mean age 9.9 years), at the end of treatment with functional appliances (T2, mean age 12.2 years), and for long-term follow-up (T3, mean age 18.3 years). Mandibular shape changes were analyzed on lateral cephalograms of the subjects in both groups via thin-plate spline (TPS) analysis. Shape differences were statistically analyzed by conducting permutation tests on Goodall F statistics.
  
  
  RESULTS
  In the long term, both the treated and control groups exhibited significant longitudinal mandibular shape changes characterized by upward and forward dislocation of point Co associated with a vertical extension in the gonial region and backward dislocation of point B.
  
  
  CONCLUSIONS
  Functional appliances induced mandible's significant posterior morphogenetic rotation over the short term. The treated and control groups demonstrated similar mandibular shape over the long term.
authors.affiliation: Department of Surgery and Translational Medicine, The University of Florence, Via del Ponte di Mezzo, 46-48, 50127, Florence, Italy. lorenzo.franchi@unifi.it.|Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, USA. lorenzo.franchi@unifi.it.
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Franchi
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome, Italy.|Department of Orthodontics, School of Dentistry, University Nostra Signora del Buon Consiglio, Tirana, Albania.
authors.forename: Chiara
authors.initials: C
authors.lastname: Pavoni
authors.affiliation: Department of Orthodontics, School of Dentistry, University Paulista, São Paulo, Brazil.
authors.forename: Kurt
authors.initials: K
authors.lastname: Faltin
authors.affiliation: Department of Orthodontics, School of Dentistry, University Paulista, São Paulo, Brazil.|Department of Pediatric and Social Dentistry, Dental School of Araçatuba, São Paulo State University "Júlio de Mesquita Filho", Araçatuba, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Bigliazzi
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome, Italy.
authors.forename: Francesca
authors.initials: F
authors.lastname: Gazzani
authors.affiliation: Department of Clinical Sciences and Translational Medicine, University of Rome 'Tor Vergata', Rome, Italy.|Department of Orthodontics, School of Dentistry, University Nostra Signora del Buon Consiglio, Tirana, Albania.
authors.forename: Paola
authors.initials: P
authors.lastname: Cozza
mesh_terms: D000202:Activator Appliances; D000293:Adolescent; D000375:Aging / Q000473:pathology*; D002508:Cephalometry / Q000706:statistics & numerical data; D002648:Child; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008312:Malocclusion, Angle Class II / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D008334:Mandible / Q000473:pathology; D009716:Numerical Analysis, Computer-Assisted; D009929:Organ Size; D015203:Reproducibility of Results; D063173:Retrognathia / Q000150:complications / Q000473:pathology* / Q000628:therapy*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome
keywords: Cephalograms; Class II malocclusion; Functional appliances; Thin-plate spline analysis