title: Effects of maxillary protraction therapy on the pharyngeal airway in patients with repaired unilateral cleft lip and palate: A 3-dimensional computed tomographic study.
abstract: BACKGROUND
  The purposes of this study were to assess the effects of maxillary protraction therapy on the pharyngeal airways in patients with repaired unilateral cleft lip and palate (UCLP) 3 dimensionally.
  
  
  METHODS
  Eighteen patients with repaired UCLP and anterior crossbite (ages, 10.4 ± 1.3 years) were enrolled in the study group. Hyrax appliances and reverse headgears were used. Cone-beam computed tomography volume scans were taken before and immediately after treatment. Fourteen patients (ages, 9.6 ± 1.7 years) with UCLP who did not receive orthopedic treatment served as the control group. The volumes of the pharyngeal airways, cross-sectional areas, sagittal diameters, and transversal diameters of 3 levels of airway cross-section were measured.
  
  
  RESULTS
  After protraction, the volumes of the pharyngeal airway increased significantly. Cross-sectional area, sagittal diameter, and transversal diameter of the upper and lower pharyngeal airways also had significant increases. These changes were significant when compared with the untreated subjects except for the transversal diameter of the lower pharyngeal airway. Dimensions of the middle pharyngeal airway remained unchanged.
  
  
  CONCLUSIONS
  Maxillary protraction therapy significantly affects airway dimensions in patients with repaired UCLP 3 dimensionally.
authors.affiliation: PhD student, Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, China.
authors.forename: Zhen
authors.initials: Z
authors.lastname: Fu
authors.affiliation: Postgraduate student, Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, China.
authors.forename: Yifan
authors.initials: Y
authors.lastname: Lin
authors.affiliation: Professor, Department of Oral and Maxillofacial Surgery, School and Hospital of Stomatology, Peking University, Beijing, China.
authors.forename: Lian
authors.initials: L
authors.lastname: Ma
authors.affiliation: Professor and chair, Department of Orthodontics, School and Hospital of Stomatology, Peking University, Beijing, China. Electronic address: weiranli2003@163.com.
authors.forename: Weiran
authors.initials: W
authors.lastname: Li
mesh_terms: D000293:Adolescent; D002648:Child; D002971:Cleft Lip / Q000601:surgery*; D002972:Cleft Palate / Q000601:surgery*; D054893:Cone-Beam Computed Tomography; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008310:Malocclusion / Q000628:therapy*; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D010614:Pharynx