title: Electromyographic evaluation in children having rapid maxillary expansion.
abstract: BACKGROUND
  The aim of this study was to analyze the electromyographic activity of the masseter and temporalis muscles of children having rapid maxillary expansion (RME) with a bonded rapid maxillary expansion appliance.
  
  
  METHODS
  The sample consisted of 27 children (mean age, 8.6 years) with posterior crossbite who required RME treatment. Electromyographic activity of the masseter and temporalis muscles was analyzed before treatment and after the appliance was removed. The mean interval between the 2 analyses was 5 months. Muscular activity was electromyographically analyzed in rest position, and with maximum voluntary dental clenching and chewing. Differences in the 2 measurements were evaluated by using paired t tests.
  
  
  CONCLUSIONS
  Electromyographic analysis showed that activity of the masseter and temporalis muscles increased significantly after the expansion appliance was removed during rest, dental clenching, and habitual chewing.
authors.affiliation: Postgraduate student, Department of Pediatric Dentistry, Piracicaba School of Dentistry, State University of Campinas, São Paulo, Brazil.
authors.forename: Moara
authors.initials: M
authors.lastname: De Rossi
authors.forename: Andiara
authors.initials: A
authors.lastname: De Rossi
authors.forename: Jaime Eduardo Cecílio
authors.initials: JE
authors.lastname: Hallak
authors.forename: Mathias
authors.initials: M
authors.lastname: Vitti
authors.forename: Simone Cecílio Hallak
authors.initials: SC
authors.lastname: Regalo
mesh_terms: D002648:Child; D003818:Dentition, Mixed; D004576:Electromyography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008310:Malocclusion / Q000628:therapy; D008406:Masseter Muscle / Q000503:physiopathology*; D008409:Mastication / Q000502:physiology; D009119:Muscle Contraction / Q000502:physiology; D016382:Orthodontic Appliance Design; D018704:Orthodontic Retainers; D010155:Palatal Expansion Technique / Q000295:instrumentation; D013703:Temporal Muscle / Q000503:physiopathology*; D014716:Vertical Dimension