title: Effects of two different removable functional appliances on depth of the posterior airway space : A retrospective cephalometric study.
abstract: OBJECTIVE
  Aim of the study was the comparison of treatment effects upon pharyngeal depth in patients treated with either (1) S-II-appliance or (2) Activator.
  
  
  METHODS
  Pre- and posttreatment lateral cephalograms of 73 patients were analyzed using a customized set of measurements. According to predefined criteria, patients were either treated with S-II-appliance or Activator. Pharyngeal depth was assessed from cranial to caudal at six levels (P1 to P6). Paired t tests were used for intragroup and t tests for independent samples for intergroup comparisons. Results were considered statistically significant at p ≤ 0.05.
  
  
  RESULTS
  37 (22 female, 15 male) patients were treated with the S-II-appliance (mean pretreatment age 11.1 ± 1.07 years), and 36 (20 female, 16 male) patients with an Activator (mean pretreatment age 11.3 ± 1.12 years). Mean treatment time was 14 months for the S-II-appliance and 12 months for the Activator. Most measurements at the different levels showed an average increase ranging from approximately 0.5 mm to almost 2 mm. Changes were more pronounced in S-II patients. In contrast to intergroup comparisons, some intragroup comparisons revealed statistically significant differences at levels P5 (p = 0.0062) and P6 (p = 0.0155) in S-II patients and at P1-level (p = 0.0197) in Activator patients.
  
  
  CONCLUSIONS
  Both appliances similarly led to an increase of the pharyngeal depth. The sites of statistically significant changes differed.
authors.affiliation: Orthodontic Practice, Reinheim, Germany.|Department of Orthodontics, University of Heidelberg, Heidelberg, Germany.
authors.forename: Jan
authors.initials: J
authors.lastname: Hourfar
authors.affiliation: Orthodontic Practice, Tönisvorst, Germany.|Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany.
authors.forename: Gero Stefan Michael
authors.initials: GS
authors.lastname: Kinzinger
authors.affiliation: Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany.
authors.forename: Luisa Katharina
authors.initials: LK
authors.lastname: Meißner
authors.affiliation: Department of Orthodontics, Saarland University, Kirrberger Strasse 100, 66424, Homburg/Saar, Germany. joerg.lisson@uniklinikum-saarland.de.
authors.forename: Jörg Alexander
authors.initials: JA
authors.lastname: Lisson
mesh_terms: D002508:Cephalometry; D002648:Child; D017267:Dental Prosthesis Design; D019544:Equipment Failure Analysis; D005260:Female; D006801:Humans; D008297:Male; D008312:Malocclusion, Angle Class II / Q000000981:diagnostic imaging / Q000473:pathology* / Q000628:therapy; D010614:Pharynx / Q000000981:diagnostic imaging / Q000473:pathology*; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity
keywords: Activator; Angle Class II; Cephalometric study; Pharyngeal depth; S-II-Appliance