title: Three-dimensional treatment outcomes in Class II patients treated with the Herbst appliance: a pilot study.
abstract: BACKGROUND
  The aims of this study were to analyze 3-dimensional skeletal changes in subjects with Class II malocclusion treated with the Herbst appliance and to compare these changes with treated Class II controls using 3-dimensional superimposition techniques.
  
  
  METHODS
  Seven consecutive Herbst patients and 7 Class II controls treated with Class II elastics who met the inclusion criteria had cone-beam computed tomographs taken before treatment, and either after Herbst removal or at posttreatment for the control subjects. Three-dimensional models were generated from the cone-beam computed tomography images, registered on the anterior cranial bases, and analyzed using color maps and point-to-point measurements.
  
  
  RESULTS
  The Herbst patients demonstrated anterior translation of the glenoid fossae and condyles (right anterior fossa, 1.69 ± 0.62 mm; left anterior fossa, 1.43 ± 0.71 mm; right anterior condyle, 1.20 ± 0.41 mm; left anterior condyle, 1.29 ± 0.57 mm), whereas posterior displacement predominated in the controls (right anterior fossa, -1.51 ± 0.68 mm; left anterior fossa, -1.31 ± 0.61 mm; right anterior condyle, -1.20 ± 0.41 mm; left anterior condyle, -1.29 ± 0.57 mm; P <0.001). There was more anterior projection of B-point in the Herbst patients (2.62 ± 1.08 mm vs 1.49 ± 0.79 mm; P <0.05). Anterior displacement of A-point was more predominant in the controls when compared with the Herbst patients (1.20 ± 0.53 mm vs -1.22 ± 0.43 mm; P <0.001).
  
  
  CONCLUSIONS
  Class II patients treated with the Herbst appliance demonstrated anterior displacement of the condyles and glenoid fossae along with maxillary restraint when compared with the treated Class II controls; this might result in more anterior mandibular projection.
authors.affiliation: Private practice, Santa Clarita, Calif.
authors.forename: Megan
authors.initials: M
authors.lastname: LeCornu
authors.forename: Lucia H S
authors.initials: LH
authors.lastname: Cevidanes
authors.forename: Hongtu
authors.initials: H
authors.lastname: Zhu
authors.forename: Chih-Da
authors.initials: CD
authors.lastname: Wu
authors.forename: Brent
authors.initials: B
authors.lastname: Larson
authors.forename: Tung
authors.initials: T
authors.lastname: Nguyen
mesh_terms: D000293:Adolescent; D000704:Analysis of Variance; D059925:Anatomic Landmarks; D016022:Case-Control Studies; D054893:Cone-Beam Computed Tomography / Q000379:methods; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D008297:Male; D008312:Malocclusion, Angle Class II / Q000473:pathology / Q000628:therapy*; D008334:Mandible / Q000033:anatomy & histology / Q000000981:diagnostic imaging* / Q000254:growth & development; D008437:Maxilla / Q000033:anatomy & histology / Q000000981:diagnostic imaging*; D017289:Orthodontic Appliances, Functional; D009971:Orthodontics, Corrective / Q000295:instrumentation* / Q000379:methods; D010865:Pilot Projects; D013701:Temporal Bone / Q000000981:diagnostic imaging*; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging*; D016896:Treatment Outcome