title: Nasal obstruction and male gender contribute to the persistence of mouth opening during sleep in CPAP-treated obstructive sleep apnoea.
abstract: OBJECTIVE
  During continuous positive airway pressure (CPAP) treatment, some patients with obstructive sleep apnoea syndrome (OSAS) require an oronasal mask (ONM) to prevent excessive mouth leakage. Factors contributing to sleep-related mouth opening under CPAP treatment remain known. We compared mouth opening during sleep in patients treated with CPAP by nasal mask (NM) versus ONM.
  
  
  METHODS
  Cross-sectional prospective study: patients treated with CPAP for at least 4 months underwent a sleep recording using a type 4 monitoring device (Brizzy-Nomics) that records mouth opening via a magnetometric distance meter. Clinical assessment included anthropometry, smoking status and the Mallampati score. Nasal obstruction was assessed by the Nasal Obstruction Symptom Evaluation questionnaire.
  
  
  RESULTS
  Thirty-eight patients were included, 34 analysed (22 men; age = 57.4 (53; 62) years; body mass index = 32.6 (29.1; 35.2) kg/m(2) ; median (25th; 75th)). Twenty-seven patients were treated with NM and seven with ONM. Patients with ONM were more often active smokers and trended to have greater nasal obstruction and lower forced expiratory volume in 1 s. They also exhibited a greater mouth opening during sleep (median (25th;75th) = 13.0 (11.0; 15.0) vs 6.0 (5.0; 10.0) mm, P < 0.001) and a higher oxygen desaturation index (9.5 (6.2; 15.5) vs 2.9 (1.0; 6.1) events/h, P = 0.009). In multivariate analysis, male gender and nasal obstruction were independently associated with mouth opening under ONM CPAP treatment.
  
  
  CONCLUSIONS
  After several months of CPAP treatment, some patients using ONM persist in keeping their mouths open at night. Nasal obstruction and male gender contribute to this phenomenon.
authors.affiliation: University Pierre and Marie Curie-Paris VI, Paris, France.|AGIR à dom. Association, La Tronche, France.
authors.forename: Marius
authors.initials: M
authors.lastname: Lebret
authors.affiliation: AGIR à dom. Association, La Tronche, France.|HP2 laboratory INSERM U1042, University Grenoble Alpes, Grenoble, France.
authors.forename: Nathalie
authors.initials: N
authors.lastname: Arnol
authors.affiliation: University of Health Sciences (HESAV), University of Applied Sciences and Arts of Western Switzerland (HES-SO), Lausanne, Switzerland.
authors.forename: Olivier
authors.initials: O
authors.lastname: Contal
authors.affiliation: Department of Pneumology, St Elisabeth Hospital, Namur, Belgium.
authors.forename: Jean Benoît
authors.initials: JB
authors.lastname: Martinot
authors.affiliation: HP2 laboratory INSERM U1042, University Grenoble Alpes, Grenoble, France.|Department of Physiology and Sleep, Albert Michallon Hospital, Grenoble, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Tamisier
authors.affiliation: HP2 laboratory INSERM U1042, University Grenoble Alpes, Grenoble, France.|Department of Physiology and Sleep, Albert Michallon Hospital, Grenoble, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Pepin
authors.affiliation: AGIR à dom. Association, La Tronche, France.|HP2 laboratory INSERM U1042, University Grenoble Alpes, Grenoble, France.
authors.forename: Jean-Christian
authors.initials: JC
authors.lastname: Borel
mesh_terms: D015992:Body Mass Index; D045422:Continuous Positive Airway Pressure / Q000295:instrumentation / Q000379:methods; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008397:Masks; D008875:Middle Aged; D009055:Mouth / Q000503:physiopathology; D015508:Nasal Obstruction / Q000150:complications*; D011446:Prospective Studies; D012737:Sex Factors; D020181:Sleep Apnea, Obstructive / Q000628:therapy*; D011795:Surveys and Questionnaires
keywords: masks; mouth opening; nasal obstruction; sleep apnoea