title: An investigation of cephalometric and morphological predictors of successful twin block therapy.
abstract: OBJECTIVE
  To identify predictors of overjet reduction, changes in mandibular length (Co-Me) and antero-posterior changes in mandibular position (Pog-Vert) during Twin Block therapy.
  
  
  METHODS
  Pre- and post-treatment cephalograms of 131 participants were analysed (Mean age 12.73 years +/- 1) following Twin Block therapy.
  
  
  RESULTS
  Mean annualised overjet reduction was 7.29 mm (+/- 2.99) with chin projection improving by 2.66 mm (+/- 5.37). The magnitude of the initial overjet was a strong predictor (95% CI: 0.30, 0.77, p < 0.01) of overjet reduction and change in chin position (95% CI: 0.08, 0.77, p = 0.02). Greater forward movement of Pogonion occurred if there was greater retrusion of Pogonion at the outset (95% CI: 0.15, 0.45, p < 0.01). No prognostic relationship was noted for other potential cephalometric predictors including pretreatment mandibular lower border morphology and Co-Go-Me angle.
  
  
  CONCLUSIONS
  No relationship between mandibular morphology, vertical skeletal pattern and favourable dentoalveolar and skeletal responses to Twin Block therapy could be found. These results require confirmation on an external sample.
authors.affiliation: Institute of Dentistry, Queen Mary University of London, London, United Kingdom. padhraig.fleming@gmail.com
authors.forename: Padhraig S
authors.initials: PS
authors.lastname: Fleming
authors.forename: Usman
authors.initials: U
authors.lastname: Qureshi
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Pandis
authors.forename: Andrew
authors.initials: A
authors.lastname: DiBiase
authors.forename: Robert T
authors.initials: RT
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D002508:Cephalometry / Q000379:methods*; D002648:Child; D002680:Chin / Q000473:pathology; D015331:Cohort Studies; D005147:Facial Bones / Q000473:pathology*; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy; D008334:Mandible / Q000473:pathology; D008335:Mandibular Condyle / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D017289:Orthodontic Appliances, Functional; D057887:Overbite / Q000473:pathology / Q000628:therapy; D012189:Retrospective Studies; D014716:Vertical Dimension