title: Craniofacial and upper airway morphology in pediatric sleep-disordered breathing and changes in quality of life with rapid maxillary expansion.
abstract: BACKGROUND
  The association between pediatric sleep-disordered breathing caused by upper airway obstruction and craniofacial morphology is poorly understood and contradictory. The aims of this study were to evaluate the prevalence of children at risk for sleep-disordered breathing, as identified in an orthodontic setting by validated screening questionnaires, and to examine associations with their craniofacial and upper airway morphologies. A further aim was to assess the change in quality of life related to sleep-disordered breathing for affected children undergoing rapid maxillary expansion to correct a palatal crossbite or widen a narrow maxilla.
  
  
  METHODS
  A prospective case-control study with children between 8 and 17 years of age (n = 81) at an orthodontic clinic was undertaken. The subjects were grouped as high risk or low risk for sleep-disordered breathing based on the scores from a validated 22-item Pediatric Sleep Questionnaire and the Obstructive Sleep Apnea-18 Quality of Life Questionnaire. Variables pertaining to a screening clinical examination, cephalometric assessment, and dental cast analysis were tested for differences between the 2 groups at baseline. Ten children who underwent rapid maxillary expansion were followed longitudinally until removal of the appliance approximately 9 months later with a repeated Obstructive Sleep Apnea-18 Quality of Life Questionnaire. All data were collected blinded to the questionnaire results.
  
  
  RESULTS
  The frequency of palatal crossbite involving at least 3 teeth was significantly higher in the high-risk group at 68.2%, compared with the low-risk group at 23.2% (P <0.0001). Average quality of life scores in the high-risk group indicated reduced quality of life related to sleep-disordered breathing by 16% compared with children in the low-risk group at baseline (P <0.0001). Cephalometrically, mean inferior airway space, posterior nasal spine to adenoidal mass distance, and adenoidal mass to soft palate distance were reduced in the high-risk group compared with the low-risk group by 1.87 mm (P <0.03), 2.82 mm (P <0.04), and 2.13 mm (P <0.03), respectively. The mean maxillary intercanine, maxillary interfirst premolar, maxillary interfirst molar, mandibular intercanine, and mandibular interfirst premolar widths were reduced in the high-risk group compared with the low-risk group by 4.22 mm (P <0.0001), 3.92 mm (P <0.0001), 4.24 mm (P <0.0001), 1.50 mm (P <0.01), and 1.84 mm (P <0.01), respectively. Children treated with rapid maxillary expansion showed an average improvement of 14% in quality of life scores in the high-risk group compared with the low-risk group, which showed a slight worsening in quality of life related to sleep-disordered breathing by an average of 1% (P <0.04), normalizing the quality of life scores in the high-risk children to the baseline scores compared with the low-risk group.
  
  
  CONCLUSIONS
  Children at high risk for sleep-disordered breathing are characterized by reduced quality of life, reduced nasopharyngeal and oropharyngeal sagittal dimensions, palatal crossbite, and reduced dentoalveolar transverse widths in the maxillary and mandibular arches. No sagittal or vertical craniofacial skeletal cephalometric predictors were identified for children at high risk for sleep-disordered breathing. In the short term, rapid maxillary expansion might aid in improvement of the quality of life for children with a narrow maxilla in the milder end of the sleep-disordered breathing spectrum.
authors.affiliation: Postgraduate student, Orthodontics Unit, University of Adelaide, Adelaide, Australia. Electronic address: vandykatyal@gmail.com.
authors.forename: Vandana
authors.initials: V
authors.lastname: Katyal
authors.forename: Yvonne
authors.initials: Y
authors.lastname: Pamula
authors.forename: Cathal N
authors.initials: CN
authors.lastname: Daynes
authors.forename: James
authors.initials: J
authors.lastname: Martin
authors.forename: Craig W
authors.initials: CW
authors.lastname: Dreyer
authors.forename: Declan
authors.initials: D
authors.lastname: Kennedy
authors.forename: Wayne J
authors.initials: WJ
authors.lastname: Sampson
mesh_terms: D000293:Adolescent; D016022:Case-Control Studies; D002508:Cephalometry / Q000379:methods; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000175:diagnosis* / Q000628:therapy; D008437:Maxilla / Q000033:anatomy & histology; D009666:Nose / Q000033:anatomy & histology*; D010155:Palatal Expansion Technique; D010159:Palate / Q000033:anatomy & histology*; D010614:Pharynx / Q000033:anatomy & histology*; D015995:Prevalence; D011446:Prospective Studies; D011788:Quality of Life; D012307:Risk Factors; D012891:Sleep Apnea Syndromes / Q000473:pathology*; D011795:Surveys and Questionnaires