title: Clinical estimation of mouth breathing.
abstract: BACKGROUND
  Breathing mode was objectively determined by monitoring airflow through the mouth, measuring nasal resistance and lip-seal function, and collecting information via questionnaire on the patient's etiology and symptoms of mouth breathing.
  
  
  METHODS
  The expiratory airflow through the mouth was detected with a carbon dioxide sensor for 30 minutes at rest. Fifteen men and 19 women volunteers (mean age, 22.4 +/- 2.5 years) were classified as nasal breathers, complete mouth breathers, or partial mouth breathers based on the mean duration of mouth breathing. Nasal resistance, lip-sealing function, and the subjective symptoms of mouth breathing ascertained by questionnaire were statistically compared by using 1-way and 2-way analysis of variance (ANOVA) and the chi-square test in the breathing groups.
  
  
  RESULTS
  Nasal resistance was significantly (P <0.05) greater for the mouth breathers than for the nasal breathers, and significantly (P <0.05) greater for the partial mouth breathers than for the complete mouth breathers. There were no significant differences in the subjective responses to questions about mouth breathing among the 3 groups.
  
  
  CONCLUSIONS
  Detecting airflow by carbon dioxide sensor can discriminate breathing mode. Degree of nasal resistance and subjective symptoms of mouth breathing do not accurately predict breathing mode.
authors.affiliation: Division of Orofacial Functions and Orthodontics, Department of Growth and Development of Functions, Kyushu Dental College, Kitakyushu, Japan.
authors.forename: Sachiko
authors.initials: S
authors.lastname: Fujimoto
authors.forename: Kazunori
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: Kaori
authors.initials: K
authors.lastname: Gunjigake
mesh_terms: D000328:Adult; D000403:Airway Resistance / Q000502:physiology*; D000704:Analysis of Variance; D002245:Carbon Dioxide; D016009:Chi-Square Distribution; D045853:Exhalation; D005260:Female; D006801:Humans; D008297:Male; D009058:Mouth Breathing / Q000175:diagnosis* / Q000503:physiopathology; D009666:Nose / Q000503:physiopathology*; D012123:Pulmonary Ventilation; D055815:Young Adult
chemical_list: D002245:Carbon Dioxide