title: Voice characteristics before versus after mandibular setback surgery in patients with mandibular prognathism using nonlinear dynamics and conventional acoustic analyses.
abstract: OBJECTIVE
  The purpose of this study was to explore the voice characteristics of patients with mandibular prognathism, and to investigate the effects of mandibular setback surgery on these characteristics using nonlinear dynamics and conventional acoustic analyses.
  
  
  METHODS
  Sixteen patients (8 males and 8 females) who had skeletal 3, class III malocclusion without cleft palate, and who underwent a bilateral sagittal split ramus osteotomy (BSSRO), were enrolled. As controls, 50 healthy adults (25 males and 25 females) were enrolled. The mean first LEs (mLE1) computed for each one-second interval, and the fundamental frequency (F0) and frequencies of the first and second formant (F1, F2) were calculated for each Japanese vowel.
  
  
  CONCLUSIONS
  The mLE1s for /u/ in males, and /o/ in females and the F2s for /i/ and /u/ in males, changed significantly after BSSRO. Class III voice characteristics were observed in the mLE1s for /i/ in both males and females, in the F0 for /a/, /i/, /u/ and /o/ in females, and in the F1 and F2 for /a/ in males, and the F1 for /u/ and the F2 for /i/ in females. Most of these characteristics were preserved after BSSRO.
authors.affiliation: Department of Oral and Maxillofacial Surgery, Graduate School of Medicine, Yamaguchi University, Japan. Electronic address: kmishima@yamaguchi-u.ac.jp.
authors.forename: Katsuaki
authors.initials: K
authors.lastname: Mishima
authors.forename: Norifumi
authors.initials: N
authors.lastname: Moritani
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nakano
authors.forename: Asuka
authors.initials: A
authors.lastname: Matsushita
authors.forename: Seiji
authors.initials: S
authors.lastname: Iida
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Ueyama
mesh_terms: D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D017709:Fractals; D006801:Humans; D008297:Male; D008313:Malocclusion, Angle Class III / Q000601:surgery; D008334:Mandible / Q000601:surgery; D017711:Nonlinear Dynamics; D059229:Osteotomy, Sagittal Split Ramus / Q000379:methods*; D010700:Phonetics; D011378:Prognathism / Q000601:surgery*; D012737:Sex Factors; D013061:Speech Acoustics; D014831:Voice / Q000502:physiology*; D055815:Young Adult