title: Effects of the headgear-activator Teuscher appliance in the treatment of Class II Division 1 malocclusion: a geometric morphometric study.
abstract: OBJECTIVE
  To test the hypothesis that there are no gender differences in the outcomes of patients with class II malocclusion treated with the headgear-activator Teuscher appliance (HATA).
  
  
  METHODS
  Retrospective, longitudinal
  
  
  METHODS
  Puerto Rico and Scotland, UK. Thirty-one patients requiring correction of class II division 1 malocclusions.
  
  
  METHODS
  Male and female patients treated using HATA.
  
  
  METHODS
  Mean pre- and post-treatment parameters derived from cephalometry subjected to t-tests, and finite-element scaling analysis (FESA), which localizes and quantifies differences between mean pre- and post-treatment configurations.
  
  
  RESULTS
  Post-treatment, cephalometry showed that for both males and females, angle SNA decreased, SNB increased, and lower facial heights increased significantly (p < 0.01). For the female post-treatment configuration, FESA revealed large size increases (approximately 20%) located in the inter-maxillary region, the ramus and mandibular body, and around the nasal and mental regions. Conversely, the lip region was diminished (approximately 20%). Similarly, male post-treatment showed size increases located in the inter-maxillary region that extended into the nasal region and the mandibular body (approximately 10-15%), and around the chin (15%). The lip region was diminished (approximately 5%).
  
  
  CONCLUSIONS
  In the attainment of a normal occlusion, both male and female patients treated for class II malocclusions using HATA exhibit antero-posterior restraint of the maxilla, improvements in the mandible maintaining facial height, and lip changes commensurate with improvements in the soft tissue profile.
authors.affiliation: Center for Craniofacial Disorders, Department of Anatomy, School of Medicine, University of Puerto Rico, San Juan 00936-5067, USA. gdsingh@rcm.upr.edu
authors.forename: G D
authors.initials: GD
authors.lastname: Singh
authors.forename: B S
authors.initials: BS
authors.lastname: Thind
mesh_terms: D000202:Activator Appliances; D000293:Adolescent; D002508:Cephalometry; D002648:Child; D005260:Female; D020342:Finite Element Analysis; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy*; D008445:Maxillofacial Development; D017289:Orthodontic Appliances, Functional; D009971:Orthodontics, Corrective / Q000295:instrumentation*; D012189:Retrospective Studies; D012737:Sex Factors; D016896:Treatment Outcome