title: Upper airway changes following single-step or stepwise advancement using the Functional Mandibular Advancer.
abstract: OBJECTIVE
  Purpose of the present study was to determine and compare possible changes in the dimensions of the pharyngeal airway, morphology of the soft palate, and position of the tongue and hyoid bone after single-step or stepwise mandibular advancement using the Functional Mandibular Advancer (FMA).
  
  
  METHODS
  The sample included 51 peak-pubertal Class II subjects. In all, 34 patients were allocated to two groups using matched randomization: a single-step mandibular advancement group (SSG) and a stepwise mandibular advancement group (SWG). Both groups were treated with FMA followed by fixed appliance therapy; the remaining 17 subjects who underwent only fixed appliance therapy constituted the control group (CG). The study was conducted using pre- and posttreatment lateral cephalometric radiographs. Data were analyzed by paired t test, one-way analysis of variance, and Pearson's correlation coefficient.
  
  
  RESULTS
  In the SWG and SSG, although increases in nasopharyngeal airway dimensions were not significant compared with those in the CG, enlargements in the oropharyngeal airway dimensions at the level of the soft palate tip and behind the tongue, and decreases in soft palate angulation, were significant. Tongue height increased significantly only in the SWG. Compared with the CG, while forward movement of the hyoid was more prominent in SSG and SWG, the change in the vertical movement of the hyoid was not significant. No significant difference between SWG and SSG was observed in pharyngeal airway, soft palate, tongue or hyoid measurements.
  
  
  CONCLUSIONS
  The mode of mandibular advancement in FMA treatment did not significantly affect changes in the pharyngeal airway, soft palate, tongue, and hyoid bone.
authors: Department of Orthodontics, Faculty of Dentistry, Ege University, 35080, Bornova, Izmir, Turkey. isilaras@gmail.com.
authors: Isil
authors: I
authors: Aras
authors: Cihangir Mah. Kaptan Sokak Avcılar, Istanbul, Turkey.
authors: Aylin
authors: A
authors: Pasaoglu
authors: Dentege ADSM, Sair Esref Bulvarı No:90, Alsancak, Izmir, Turkey.
authors: Sultan
authors: S
authors: Olmez
authors: Dent Ekol ADSM, Mavisehir, Cigli, Izmir, Turkey.
authors: Idil
authors: I
authors: Unal
authors: Department of Orthodontics, Faculty of Dentistry, Ege University, 35080, Bornova, Izmir, Turkey.
authors: Aynur
authors: A
authors: Aras
mesh_terms: D000293:Adolescent; D002508:Cephalometry; D017267:Dental Prosthesis Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D006928:Hyoid Bone / Q000002:abnormalities / Q000473:pathology*; D008297:Male; D008312:Malocclusion, Angle Class II / Q000000981:diagnostic imaging / Q000517:prevention & control*; D019186:Mandibular Advancement / Q000009:adverse effects / Q000295:instrumentation*; D017289:Orthodontic Appliances, Functional / Q000009:adverse effects*; D010160:Palate, Soft / Q000002:abnormalities / Q000000981:diagnostic imaging*; D010614:Pharynx / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011861:Radiography, Dental; D014059:Tongue / Q000002:abnormalities*; D016896:Treatment Outcome
keywords: Cephalometry; Functional orthodontic appliance; Mandibular advancement; Pharynx