title: Oropharyngeal crowding and obesity as predictors of oral appliance treatment response to moderate obstructive sleep apnea.
abstract: BACKGROUND
  Oral appliances are increasingly prescribed for patients with moderate obstructive sleep apnea (OSA) instead of nasal CPAP. However, the efficacy of oral appliances varies greatly. We hypothesized that oral appliances were not efficacious in patients with moderate OSA who were obese with oropharyngeal crowding.
  
  
  METHODS
  Japanese patients with moderate OSA were prospectively and consecutively recruited. The Mallampati score (MS) was used as an estimate of oropharyngeal crowding. Follow-up polysomnography was performed with the adjusted oral appliance in place. Responders were defined as subjects who showed a follow-up apnea-hypopnea index (AHI) of &lt; 5 with &gt; 50% reduction in baseline AHI.
  
  
  RESULTS
  The mean baseline AHI was reduced with an oral appliance from 21 ± 4 to 9.8 ± 8 in 95 subjects. Thirty-five patients were regarded as responders. Logistic regression analyses revealed that both MS and BMI could individually predict the treatment outcome. When the cutoff value of BMI was determined to be 24 kg/m2 based on a receiver operating characteristic curve, 53 obese patients (ie, BMI &gt; 24 kg/m2) with an MS of class 4 were indicative of treatment failure with a high negative predictive value (92) and a low negative likelihood ratio (0.28).
  
  
  CONCLUSIONS
  We conclude that patients with moderate OSA who are obese with oropharyngeal crowding are unlikely to respond to oral appliance treatment. This simple prediction can be applied without the need for any cumbersome tools immediately after the diagnosis of OSA.
authors.affiliation: Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan; Yoyogi Sleep Disorder Center, Tokyo, Japan; Department of Somnology, Tokyo Medical University, Tokyo, Japan. Electronic address: tsuiki@somnology.com.
authors.forename: Satoru
authors.initials: S
authors.lastname: Tsuiki
authors.affiliation: Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan; Yoyogi Sleep Disorder Center, Tokyo, Japan; Department of Somnology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Eiki
authors.initials: E
authors.lastname: Ito
authors.affiliation: Department of Anesthesiology, Graduate School of Medicine, Chiba University, Chiba, Japan.
authors.forename: Shiroh
authors.initials: S
authors.lastname: Isono
authors.affiliation: Division of Respiratory Medicine, Faculty of Medicine, The University of British, Columbia, Vancouver, BC, Canada.
authors.forename: C Frank
authors.initials: CF
authors.lastname: Ryan
authors.affiliation: Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan; Department of Somnology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Yoko
authors.initials: Y
authors.lastname: Komada
authors.affiliation: Department of Life Sciences and Bioinformatics, Graduate School of Health, Sciences, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Masato
authors.initials: M
authors.lastname: Matsuura
authors.affiliation: Japan Somnology Center, Neuropsychiatric Research Institute, Tokyo, Japan; Yoyogi Sleep Disorder Center, Tokyo, Japan; Department of Somnology, Tokyo Medical University, Tokyo, Japan.
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Inoue
mesh_terms: D005260:Female; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000150:complications*; D019186:Mandibular Advancement / Q000295:instrumentation*; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D009968:Orthodontic Appliances, Removable; D017286:Polysomnography; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D016896:Treatment Outcome