title: Dynamic comparison of pharyngeal stability during sleep in patients with obstructive sleep apnea syndrome treated with maxillomandibular advancement.
abstract: OBJECTIVE
  To compare the dynamic differences occurring in the pharynx during sleep after maxillomandibular advancement (MMA) surgery for the treatment of patients with obstructive sleep apnea syndrome.
  
  
  METHODS
  This was a prospective, cross-sectional study conducted on 20 patients (15 men and 5 women) with a polysomnography diagnosis of obstructive sleep apnea (OSA) submitted to surgical treatment with MMA. All patients were submitted to magnetic resonance (MR) during propofol-induced sleep before and 6 months after surgery. Thirty linear measurements (30 sections) were obtained over time in the retrolingual (RL) region to compare their variability before and after MMA.
  
  
  RESULTS
  The mean linear anteroposterior increase of the pharynx during induced sleep after MMA was 66 % in the RL region (P < 0.01). The coefficient of variation of the linear measurements was 117.5 % before surgery, being reduced to 51 % after surgery.
  
  
  CONCLUSIONS
  MMA promoted an important increase of the pharynx during induced sleep and a more significant change in the variability of its lumen. With a lower variation in the diameter of the organ during the respiratory movements, there is greater airway stability and a consequent maintenance of the pharyngeal lumen that reduces or even prevents pharyngeal collapse.
authors.affiliation: Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, University of São Paulo, Ribeirão Preto, SP, Brazil. anacfaria@usp.br.|Faculty of Medicine of Ribeirão Preto, University of São Paulo, Av. Bandeirantes, 3900, 14049-900, Ribeirão Preto, SP, Brazil. anacfaria@usp.br.
authors.forename: Ana Celia
authors.initials: AC
authors.lastname: Faria
authors.affiliation: Department of Biomechanics, Medicine and Rehabilitation of the Locomotor Apparatus, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Luis Vicente
authors.initials: LV
authors.lastname: Garcia
authors.affiliation: Center of Imaging Sciences and Medical Physics, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Antonio Carlos
authors.initials: AC
authors.lastname: Santos
authors.affiliation: Department of Neurology, Faculty of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Alan Luiz
authors.initials: AL
authors.lastname: Eckeli
authors.affiliation: Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, University of São Paulo, Ribeirão Preto, SP, Brazil.|Craniofacial Research Support Center, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Denny Marcos
authors.initials: DM
authors.lastname: Garcia
authors.affiliation: Department of Ophthalmology, Otorhinolaryngology and Head and Neck Surgery, University of São Paulo, Ribeirão Preto, SP, Brazil.|Craniofacial Research Support Center, University of São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Francisco Verissimo
authors.initials: FV
authors.lastname: Mello-Filho
mesh_terms: D000328:Adult; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D019186:Mandibular Advancement; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D010614:Pharynx / Q000000981:diagnostic imaging / Q000503:physiopathology*; D017286:Polysomnography; D011446:Prospective Studies; D020181:Sleep Apnea, Obstructive / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000628:therapy*
keywords: Magnetic resonance; Maxillomandibular advancement; Obstructive sleep apnea; Pharynx; Surgical modifications