title: Three-dimensional cone-beam computed tomography analysis of enlargement of the pharyngeal airway by the Herbst appliance.
abstract: BACKGROUND
  Pharyngeal airway size is increasingly recognized as an important factor in obstructive sleep apnea. However, few studies have examined the changes of pharyngeal airway form after dental procedures for treating obstructive sleep apnea during growth. The purpose of this study was to evaluate the effect of the Herbst appliance on the 3-dimensional form of the pharyngeal airway using cone-beam computed tomography.
  
  
  METHODS
  Twenty-four Class II subjects (ANB, ≥5°; 11 boys; mean age, 11.6 years) who required Herbst therapy with edgewise treatment had cone-beam computed tomography images taken before and after Herbst treatment. Twenty Class I control subjects (9 boys; mean age, 11.5 years) received edgewise treatment only. The volume, depth, and width of the pharyngeal airway were compared between the groups using measurements from 3-dimensional cone-beam computed tomography images of the entire pharyngeal airway.
  
  
  RESULTS
  The increase of the oropharyngeal airway volume in the Herbst group (5000.2 mm(3)) was significantly greater than that of the control group (2451.6 mm(3)). Similarly, the increase of the laryngopharyngeal airway volume in the Herbst group (1941.8 mm(3)) was significantly greater than that of the control group (1060.1 mm(3)).
  
  
  CONCLUSIONS
  The Herbst appliance enlarges the oropharyngeal and laryngopharyngeal airways. These results may provide a useful assessment of obstructive sleep apnea treatment during growth.
authors.affiliation: Associate professor, Field of Developmental Medicine, Health Research Course, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan. Electronic address: yamame@dent.kagoshima-u.ac.jp.
authors.forename: Tomonori
authors.initials: T
authors.lastname: Iwasaki
authors.affiliation: Assistant professor, Field of Developmental Medicine, Health Research Course, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Yoshihiko
authors.initials: Y
authors.lastname: Takemoto
authors.affiliation: Assistant professor, Field of Developmental Medicine, Health Research Course, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Emi
authors.initials: E
authors.lastname: Inada
authors.affiliation: Assistant professor, Field of Developmental Medicine, Health Research Course, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Hideo
authors.initials: H
authors.lastname: Sato
authors.affiliation: Associate professor, Division of Pediatric Dentistry, Department of Oral Health Science, Course of Oral Life Science, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
authors.forename: Issei
authors.initials: I
authors.lastname: Saitoh
authors.affiliation: Private practice, Himeji, Japan.
authors.forename: Eriko
authors.initials: E
authors.lastname: Kakuno
authors.affiliation: Private practice, Himeji, Japan.
authors.forename: Ryuzo
authors.initials: R
authors.lastname: Kanomi
authors.affiliation: Professor and chairman, Field of Developmental Medicine, Health Research Course, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, Japan.
authors.forename: Youichi
authors.initials: Y
authors.lastname: Yamasaki
mesh_terms: D000293:Adolescent; D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D019412:Anatomy, Cross-Sectional; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D002648:Child; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007830:Larynx / Q000000981:diagnostic imaging; D008137:Longitudinal Studies; D008297:Male; D008312:Malocclusion, Angle Class II / Q000628:therapy; D008334:Mandible / Q000000981:diagnostic imaging; D008437:Maxilla / Q000000981:diagnostic imaging; D009295:Nasal Bone / Q000000981:diagnostic imaging; D009960:Oropharynx / Q000000981:diagnostic imaging; D009967:Orthodontic Appliances; D017289:Orthodontic Appliances, Functional; D010614:Pharynx / Q000000981:diagnostic imaging*; D012189:Retrospective Studies; D012658:Sella Turcica / Q000000981:diagnostic imaging