title: Effect of Rapid Maxillary Expansion on Voice.
abstract: OBJECTIVE
  The purpose of this investigation is to evaluate the effect of rapid maxillary expansion (RME) on the fundamental frequency (F0) and formant frequencies F1-F4.
  
  
  METHODS
  Cross-sectional study.
  
  
  METHODS
  A total of 14 consecutive patients between the ages of 9.6 years and 15 years with a constricted maxilla undergoing RME were included in this study. Measurements were made before (T1) and after treatment (T2). These included maxillary arch length, depth, width, and perimeter in addition to F0, habitual pitch, and formants F1, F2, F3, and F4 for the vowels /ɑ/, /i/, /o/, and /u/.
  
  
  RESULTS
  There was a significant difference in the mean of F1/ɑ/ and F2/ɑ/ before and after treatment (P value of 0.04 and 0.013, respectively). It is worth noting that F1/ɑ/ decreased in 11 and F2/ɑ/ decreased in 10 of the 14 subjects.
  
  
  CONCLUSIONS
  The application of RME in the treatment of maxillary constriction leads to a significant lowering of the first and second formants for the vowel /ɑ/ in most subjects. Subjects undergoing rapid maxillary application should be aware of the potential change in voice quality especially in case of professional voice users.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Division of Orthodontics and Dentofacial Orthopedics, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Anthony T
authors.initials: AT
authors.lastname: Macari
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Georges
authors.initials: G
authors.lastname: Ziade
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Division of Orthodontics and Dentofacial Orthopedics, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Mohannad
authors.initials: M
authors.lastname: Khandakji
authors.affiliation: Department of Internal Medicine, American University of Beirut Medical Center, Beirut, Lebanon.
authors.forename: Hani
authors.initials: H
authors.lastname: Tamim
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, American University of Beirut Medical Center, Beirut, Lebanon. Electronic address: ah77@aub.edu.lb.
authors.forename: Abdul-Latif
authors.initials: AL
authors.lastname: Hamdan
mesh_terms: D000162:Acoustics; D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D008437:Maxilla / Q000473:pathology / Q000601:surgery*; D008439:Maxillary Diseases / Q000175:diagnosis / Q000601:surgery*; D010155:Palatal Expansion Technique / Q000009:adverse effects*; D013061:Speech Acoustics; D013068:Speech Production Measurement; D013997:Time Factors; D016896:Treatment Outcome; D014833:Voice Quality
keywords: Formants; Fundamental frequency; Maxilla; Voice; Vowel