title: Phonetic analysis during treatment with rapid maxillary expander.
abstract: OBJECTIVE
  To investigate possible changes and/or device-related impairments in phonetic habits produced by rapid maxillary expansion (RME).
  
  
  METHODS
  Thirty-five patients scheduled for RME were divided into two groups: Group A (banded two-arm Hyrax) and Group B (banded four-arm Hyrax). Speech samples were collected at six time points, before, during and after RME removal. Acoustical analysis was performed using PRAAT and BioVoice analysis tools. Ten volunteers completed a questionnaire on the acceptability of patient's speech. Maxillary dimensions and palatal volume were measured on dental casts before and after expansion using a digital gauge.
  
  
  RESULTS
  Voice analysis showed an increase in the peak frequency of fricative consonants (/s/,/ʃ/) after expansion, whereas there was no change of formant frequencies of palatal consonants (/ɲ/,/ʎ/). Vowel /i/ displayed a lowering of the first formant frequency, and an increase in the second and third formant frequencies. After bonding, Group B showed both a greater reduction in the peak frequency of fricatives and a greater increase in the formant frequencies of palatal consonants than Group A.
  
  
  CONCLUSIONS
  Rapid maxillary expansion causes a slight phonetic change in the acoustical parameters of both consonants and vowels. The two-arm Hyrax caused less speech impairment than the four-arm Hyrax during the treatment.
authors.affiliation: Department of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Biondi
authors.affiliation: Department of Information Engineering, University of Firenze, Firenze, Italy.|Department of Electrical, Electronic and Information Engineering (DEI) "Guglielmo Marconi", University of Bologna, Bologna, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Bandini
authors.affiliation: Department of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: L
authors.initials: L
authors.lastname: Lombardo
authors.affiliation: Department of Information Engineering, University of Firenze, Firenze, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Orlandi
authors.affiliation: Department of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: G
authors.initials: G
authors.lastname: Siciliani
authors.affiliation: Department of Information Engineering, University of Firenze, Firenze, Italy.
authors.forename: C
authors.initials: C
authors.lastname: Manfredi
mesh_terms: D000293:Adolescent; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D010155:Palatal Expansion Technique; D010700:Phonetics; D013061:Speech Acoustics
keywords: maxillary expansion; palate; phonetics; speech acoustic