title: Evaluation of true vocal fold growth as a function of age.
abstract: OBJECTIVE
  To evaluate change in true vocal fold length as a function of age.
  
  
  METHODS
  Prospective study.
  
  
  METHODS
  Tertiary aerodigestive center.
  
  
  METHODS
  In total, 205 patients (aged 1 month to 20 years), of whom 87 (42.4%) were female and 118 (57.6%) male, were included. Lengths of the total vocal fold (TVFL), membranous vocal fold (MVFL), and cartilaginous vocal fold (CVFL) were measured during direct laryngoscopy. Membranous-to-cartilaginous (M/C) ratios were calculated.
  
  
  RESULTS
  For patients younger than 1 year, mean (SD) MVFL was 4.4 (1.3) mm for females and 4.9 (1.8) mm for males. At age 17 years, mean (SD) MVFL was 12.3 (2.1) mm for females and 14.0 (1.4) mm for males. Mean TVFL, MVFL, and CVFL increased an average of 0.7 mm, 0.5 mm, and 0.2 mm per year in linear fashion, respectively (linear regression, P < .0001). The M/C ratio did not significantly change with age (P = .33). Mean TVFL, MVFL, and CVFL showed no statistical difference between males and females (P = .27, .11, and .75, respectively).
  
  
  CONCLUSIONS
  This is the largest longitudinal pediatric study specifically examining vocal fold length as a function of age. Each length of the true vocal fold appeared to linearly increase for both females and males. The M/C ratio remained relatively constant, unlike previously reported data, possibly due to in vivo vs cadaveric measurements. These findings suggest that critical periods of development in females and males are not explainable by changes in vocal fold length alone, and other factors such as vocal fold layers need further exploration.
authors.affiliation: Pediatric Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.
authors.forename: Derek J
authors.initials: DJ
authors.lastname: Rogers
authors.affiliation: Pediatric Otolaryngology, Yale-New Haven Hospital, New Haven, Connecticut, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Setlur
authors.affiliation: Pediatric Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA.
authors.forename: Nikhila
authors.initials: N
authors.lastname: Raol
authors.affiliation: Brigham and Women's Hospital, Massachusetts General Hospital, and Harvard Catalyst, Boston, Massachusetts, USA.
authors.forename: Rie
authors.initials: R
authors.lastname: Maurer
authors.affiliation: Pediatric Otolaryngology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA Christopher_Hartnick@meei.harvard.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Hartnick
mesh_terms: D000293:Adolescent; D000367:Age Factors; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D007223:Infant; D007828:Laryngoscopy; D008137:Longitudinal Studies; D008297:Male; D009929:Organ Size; D011446:Prospective Studies; D012737:Sex Factors; D014827:Vocal Cords / Q000254:growth & development*; D014831:Voice; D055815:Young Adult
keywords: pediatric laryngology; pediatric voice; vocal fold length