title: Upper airway resistance during growth: A longitudinal study of children from 8 to 17 years of age.
abstract: OBJECTIVE
  To study upper airway breathing in 115 children annually from 8 to 17 years of age with the hypothesis that upper airway respiratory needs increase steadily during growth and show sexual dimorphism.
  
  
  METHODS
  To calculate nasal resistance, airflow rate (mL/s) and oronasal pressures (cmH2O) were measured during rest breathing in a seated position using the pressure-flow technique.
  
  
  RESULTS
  Median values of oronasal pressure ranged at different ages in girls from 0.88 to 1.13 and in boys from 0.92 to 1.44 cmH2O, being 0.95 and 0.93 cmH2O at the age of 17 years, respectively. The gender differences were statistically significant in four age groups (P < .05 by the Mann-Whitney test). Mean values of nasal resistance decreased from 8 to 17 years of age in girls from 4.0 (±3.27) to 2.4 (±2.30) and in boys from 3.3 (±2.48) to 1.5 (±0.81) cmH2O/L/s. However, there was an increase in resistance in 11-year-old girls and 12-year-old boys and at the age of 15 in both genders (P < .05 by paired t-test).
  
  
  CONCLUSIONS
  Respiratory efforts stabilize oronasal pressure to maintain vital functions at optimal level. Nasal resistance decreased with age but increased temporarily at the prepubertal and pubertal phases, in accordance with other growth and possibly hormonal changes. When measuring upper airway function for clinical purposes, especially in patients with sleep apnea, asthma, allergies, cleft palate, or maxillary expansion, the measurements need to be compared with age- and gender-specific values obtained from healthy children.
authors.affiliation: a   Professor, Department of Orthodontics, Institute of Dentistry, University of Eastern Finland, and Kuopio University Hospital, Kuopio, Finland.
authors.forename: Maija T
authors.initials: MT
authors.lastname: Laine-Alava
authors.affiliation: b   PhD Student, Institute of Dentistry, University of Eastern Finland, Kuopio, Finland.
authors.forename: Siiri
authors.initials: S
authors.lastname: Murtolahti
authors.affiliation: c   Assistant Professor, Department of Orthodontics, Institute of Dentistry, University of Michigan, Ann Arbor, MI.
authors.forename: Ulla K
authors.initials: UK
authors.lastname: Crouse
authors.affiliation: d   Professor, UNC Craniofacial Center, University of North Carolina, Chapel Hill, NC.
authors.forename: Donald W
authors.initials: DW
authors.lastname: Warren
mesh_terms: D000293:Adolescent; D000403:Airway Resistance; D002648:Child; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009666:Nose; D010155:Palatal Expansion Technique; D012119:Respiration
keywords: Nasal obstruction; Nasal resistance; Oronasal pressure; Pressure-flow technique; Upper airways