title: All on Four® fixed implant support rehabilitation: a masticatory function study.
abstract: BACKGROUND
  Fixed implant-supported prostheses according to All-on-Four® (Nobel Biocare, Goteborg, Sweden) principles have become an accepted treatment modality in totally edentulous patients, whereas the functional effect of this therapy is limited.
  
  
  OBJECTIVE
  The purpose of this study was to evaluate the muscular function of patients totally rehabilitated with All-on-Four.
  
  
  METHODS
  This study evaluated 63 patients. Twenty-one patients were successfully rehabilitated with maxillary and mandibular All-on-Four (no dropout implants, satisfactory aesthetic and function demands prosthesis), 21 patients were dentate, and 21 were rehabilitated with double complete dentures. Electromyography was carried out during clenching, nonhabitual and habitual chewing, and rest. All values were standardized as percentage of a maximum voluntary contraction. Data were analyzed by ANOVA to compare groups and paired t-test was used for comparison between sides within each group.
  
  
  RESULTS
  All groups presented symmetric muscular activity. The All-on-Four and dentate groups had a similar muscles surface electromyography (sEMG) contraction pattern, that is, a higher sEMG activity of masseter than temporalis muscles, differing (p ≤ .05) from those of denture group. Not one statistical difference was found between All-on-Four and dentate groups.
  
  
  CONCLUSIONS
  The muscular function similarity of All-on-Four and dentate patients shows that this treatment concept may be considered as a good option for oral rehabilitation in edentulous patients.
authors.affiliation: School of Dentistry, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.
authors.forename: Moara
authors.initials: M
authors.lastname: De Rossi
authors.forename: Carla Moreto
authors.initials: CM
authors.lastname: Santos
authors.forename: Reginaldo
authors.initials: R
authors.lastname: Migliorança
authors.forename: Simone Cecílio Hallak
authors.initials: SC
authors.lastname: Regalo
mesh_terms: D000328:Adult; D000368:Aged; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D003824:Denture, Complete; D004576:Electromyography; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D057893:Immediate Dental Implant Loading; D007575:Jaw, Edentulous / Q000534:rehabilitation; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation; D008297:Male; D008406:Masseter Muscle / Q000502:physiology*; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D011862:Radiography, Panoramic
chemical_list: D015921:Dental Implants
keywords: All-on-Four®; electromyography; fixed implant prosthesis; implant; masticatory muscles