title: Effect of new dentures on interocclusal distance during speech.
abstract: OBJECTIVE
  The aim of this study was to investigate the changes in interocclusal distance during the pronunciation of /m/ and /s/ sounds in the Portuguese language, in partially edentulous patients before and after insertion of new dentures.
  
  
  METHODS
  Subjects were divided into a control group consisting of 18 completely dentate patients and an experimental group consisting of 18 patients who were edentulous in the maxilla and classified as Kennedy Class I in the mandible. The experimental group had new dentures placed and the occlusal vertical dimension corrected. A magnetic jaw-tracking device measured the interocclusal distance during pronunciation of the /m/ and /s/ phonemes. Interocclusal distance evaluations were carried out in a single session for the control group. In the experimental group, the measurements were carried out before insertion of new dentures; immediately after insertion; and after 6 and 24 hours; 2 days; 1 and 2 weeks; 1, 2, 3, and 6 months; and 1 year.
  
  
  RESULTS
  Comparison between groups revealed significant difference in interocclusal distance for the /m/ sound both before and after insertion of dentures up to 2 months. For the /s/ phoneme, there was no difference between the groups before prosthesis insertion, or after 3, 6, and 12 months of prosthesis use. There were significant differences for the /m/ sound only at 6 and 12 months after new denture insertion, and for the /s/ sound at all periods evaluated.
  
  
  CONCLUSIONS
  Insertion of new dentures, with the vertical dimension corrected, changes the interocclusal distance of speech during phonation of /m/ and /s/ sounds.
authors.affiliation: Department of Prosthesis and Periodontology, Faculty of Dentistry of Piracicaba, University of Campinas, São Paulo, Brazil. regarcia@fop.unicamp.br
authors.forename: Renata Cunha Matheus
authors.initials: RC
authors.lastname: Rodrigues Garcia
authors.forename: Viviane Maia Barreto
authors.initials: VM
authors.lastname: Oliveira
authors.forename: Altair A
authors.initials: AA
authors.lastname: Del Bel Cury
mesh_terms: D000328:Adult; D000368:Aged; D003779:Denture Design; D003824:Denture, Complete; D003829:Denture, Partial; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007575:Jaw, Edentulous / Q000503:physiopathology / Q000534:rehabilitation; D007576:Jaw, Edentulous, Partially / Q000503:physiopathology / Q000534:rehabilitation; D008297:Male; D008334:Mandible / Q000502:physiology; D008875:Middle Aged; D009068:Movement; D010700:Phonetics; D011174:Portugal; D013060:Speech / Q000502:physiology*; D014716:Vertical Dimension