title: Displacement of mandibular removable partial denture bases by tongue movements during speech.
abstract: OBJECTIVE
  The purpose of this study was to evaluate denture base displacement caused by tongue movements during speech.
  
  
  METHODS
  Ten patients with new Kennedy Class I mandibular removable partial dentures participated in this study. All prostheses were made according to a standardized protocol. Denture base displacements when speaking a test sentence were measured with a computer-aided device that was developed for this purpose. It included 4 Hall sensors, mounted on a paraocclusal splint and magnets, embedded in the denture bases. Vertical and transverse base displacements were calculated from Hall voltages. Clasp retention was measured with a dynamometer.
  
  
  RESULTS
  Mean displacements were 145 microns seating, 72 microns unseating, 87 microns buccally, and 74 microns lingually. Seating and unseating displacements differed statistically significantly in absolute values. Mean clasp retention was 2.5 N. No correlation was found between clasp retention and unseating base displacements.
  
  
  CONCLUSIONS
  Tongue movements during speech induced only minimal displacements in the dentures investigated. Additionally, tongue activity was found to be denture stabilizing rather than denture displacing in this study.
authors.affiliation: Department of Prosthetic Dentistry, Medical Faculty Carl Gustav Carus, Technical University of Dresden, Germany. boening@rcs.urz.tu-dresden.de
authors.forename: K W
authors.initials: KW
authors.lastname: Boening
mesh_terms: D000328:Adult; D000368:Aged; D016734:Dental Clasps; D003819:Denture Bases; D003781:Denture Retention; D003832:Denture, Partial, Removable; D005069:Evaluation Studies as Topic; D005260:Female; D006801:Humans; D008297:Male; D008334:Mandible; D008875:Middle Aged; D009068:Movement; D013060:Speech / Q000502:physiology; D014059:Tongue / Q000502:physiology