title: Correlation between skeletal changes by maxillary protraction and upper airway dimensions.
abstract: OBJECTIVE
  To describe the correlation between the skeletal changes induced by maxillary protraction treatment and the sagittal airway dimension associated with tongue, soft palate, and hyoid bone position in skeletal Class III children.
  
  
  METHODS
  Twenty Class III patients (5 boys, 15 girls; mean age, 9.4 ± 1.8 years) treated with a maxillary protraction appliance were included in this study. Pretreatment and posttreatment cephalometric radiographs were analyzed; linear and angular measurements were performed by an expert orthodontist. The correlation between treatment changes in craniofacial morphology and those in upper airway, tongue, soft palate, and hyoid position was evaluated by Pearson's correlation analysis.
  
  
  RESULTS
  A significant increase in maxillary forward displacement, inhibition of mandibular forward growth, and clockwise rotation of the mandible were observed. Simultaneously, nasopharyngeal airway measurements PNS-ad1 and PNS-ad2 significantly increased by 1.4 mm and 1.9 mm, respectively. A correlation analysis revealed that maxillary protraction had a positive relationship with PNS-ad1 and PNS-ad2.
  
  
  CONCLUSIONS
  The nasopharyngeal airway dimensions can be improved in the short term with maxillary protraction in skeletal Class III children.
authors.affiliation: Graduate School of Dentistry, Kyung Hee University, Dongdaemoon-Ku, Seoul, South Korea.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Lee
authors.forename: Ki-Ho
authors.initials: KH
authors.lastname: Park
authors.forename: Seong-Hun
authors.initials: SH
authors.lastname: Kim
authors.forename: Young-Guk
authors.initials: YG
authors.lastname: Park
authors.forename: Su-Jung
authors.initials: SJ
authors.lastname: Kim
mesh_terms: D000402:Airway Obstruction / Q000628:therapy*; D002508:Cephalometry; D002648:Child; D005115:Extraoral Traction Appliances; D005260:Female; D006801:Humans; D006928:Hyoid Bone / Q000033:anatomy & histology; D008297:Male; D008313:Malocclusion, Angle Class III / Q000628:therapy*; D008334:Mandible / Q000033:anatomy & histology / Q000254:growth & development; D008437:Maxilla / Q000033:anatomy & histology* / Q000254:growth & development; D008445:Maxillofacial Development; D009305:Nasopharynx / Q000033:anatomy & histology*; D009972:Orthodontics, Interceptive / Q000295:instrumentation; D010160:Palate, Soft / Q000033:anatomy & histology; D018709:Statistics, Nonparametric; D014059:Tongue / Q000033:anatomy & histology; D016896:Treatment Outcome