title: Lateral Pharyngeal Wall Tension After Maxillomandibular Advancement for Obstructive Sleep Apnea Is a Marker for Surgical Success: Observations From Drug-Induced Sleep Endoscopy.
abstract: OBJECTIVE
  The efficacy of maxillomandibular advancement (MMA) for obstructive sleep apnea (OSA) with anatomic airway changes has previously been studied using static imaging and endoscopy in awake subjects. The aim of the present study was to use drug-induced sleep endoscopy (DISE) to evaluate the dynamic upper airway changes in sleeping subjects before and after MMA and their association with the surgical outcome.
  
  
  METHODS
  This was a retrospective cohort study of subjects with OSA who had undergone MMA at the Stanford University Sleep Surgery Division from July 2013 to July 2014. The subjects were included if perioperative polysomnography and DISE had been performed. The predictor variable was the perioperative DISE velum-oropharynx-tongue-epiglottis score. The outcome variables were the apnea-hypopnea index (AHI), oxygen-desaturation index (ODI), and Epworth Sleepiness Scale (ESS). A subgroup analysis was performed for the subjects who had undergone primary and secondary MMA. The statistical analyses included Cronbach's α coefficient, the McNemar test, and the independent Student t test. The P value was set at <.01.
  
  
  RESULTS
  A total of 16 subjects (15 males, 1 female) were included in the present study, with an average age of 47 ± 10.9 years and body mass index of 29.4 ± 5.1 kg/m(2). Significant post-MMA decreases were found in the AHI (from 59.8 ± 25.6 to 9.3 ± 7.1 events/hr) and ODI (from 45 ± 29.7 to 5.7 ± 4.1 events/hr; P < .001). Greater improvement in the AHI occurred in the primary MMA group (P = .022). The post-MMA change in airway collapse was most significant at the lateral pharyngeal wall (P = .001). The subjects with the most improvement in lateral pharyngeal wall collapsibility demonstrated the largest changes in the AHI (from 60.0 ± 25.6 events/hr to 7.5 ± 3.4 events/hr) and ODI (from 46.7 ± 29.8 to 5.3 ± 2 events/hr; P = .002).
  
  
  CONCLUSIONS
  Using DISE, we observed that after MMA, the greatest reduction in upper airway collapsibility is seen at the lateral pharyngeal wall of the oropharynx, followed by the velum, and then the tongue base. The stability of the lateral pharyngeal wall is a marker of surgical success after MMA using the AHI, ODI, and ESS.
authors.affiliation: Assistant Professor, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA. Electronic address: ycliu@stanford.edu.
authors.forename: Stanley Yung-Chuan
authors.initials: SY
authors.lastname: Liu
authors.affiliation: Visiting Research Scholar, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA; Lecturer, Fu Jen Catholic University School of Medicine, Taipei, Taiwan; and Attending Physician, Department of Otolaryngology, Cathay General Hospital, Taipei, Taiwan.
authors.forename: Leh-Kiong
authors.initials: LK
authors.lastname: Huon
authors.affiliation: Adjunct Professor, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Nelson B
authors.initials: NB
authors.lastname: Powell
authors.affiliation: Clinical Professor, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Robert
authors.initials: R
authors.lastname: Riley
authors.affiliation: Medical Student, Stanford University School of Medicine, Stanford, CA.
authors.forename: Hyunje Grace
authors.initials: HG
authors.lastname: Cho
authors.affiliation: Clinical Instructor, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Carlos
authors.initials: C
authors.lastname: Torre
authors.affiliation: Assistant Clinical Professor, Division of Sleep Surgery, Department of Otolaryngology, Stanford University School of Medicine, Stanford, CA.
authors.forename: Robson
authors.initials: R
authors.lastname: Capasso
mesh_terms: D000328:Adult; D004724:Endoscopy / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D019186:Mandibular Advancement; D008437:Maxilla / Q000601:surgery*; D008875:Middle Aged; D010614:Pharynx / Q000601:surgery*; D017286:Polysomnography; D012189:Retrospective Studies; D012890:Sleep / Q000187:drug effects*; D020181:Sleep Apnea, Obstructive / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome