title: A novel colourimetric technique to assess chewing function using two-coloured specimens: Validation and application.
abstract: OBJECTIVE
  Chewing efficiency may be evaluated using cohesive specimen, especially in elderly or dysphagic patients. The aim of this study was to evaluate three two-coloured chewing gums for a colour-mixing ability test and to validate a new purpose built software (ViewGum©).
  
  
  METHODS
  Dentate participants (dentate-group) and edentulous patients with mandibular two-implant overdentures (IOD-group) were recruited. First, the dentate-group chewed three different types of two-coloured gum (gum1-gum3) for 5, 10, 20, 30 and 50 chewing cycles. Subsequently the number of chewing cycles with the highest intra- and inter-rater agreement was determined visually by applying a scale (SA) and opto-electronically (ViewGum©, Bland-Altman analysis). The ViewGum© software determines semi-automatically the variance of hue (VOH); inadequate mixing presents with larger VOH than complete mixing. Secondly, the dentate-group and the IOD-group were compared.
  
  
  RESULTS
  The dentate-group comprised 20 participants (10 female, 30.3±6.7 years); the IOD-group 15 participants (10 female, 74.6±8.3 years). Intra-rater and inter-rater agreement (SA) was very high at 20 chewing cycles (95.00-98.75%). Gums 1-3 showed different colour-mixing characteristics as a function of chewing cycles, gum1 showed a logarithmic association; gum2 and gum3 demonstrated more linear behaviours. However, the number of chewing cycles could be predicted in all specimens from VOH (all p<0.0001, mixed linear regression models). Both analyses proved discriminative to the dental state.
  
  
  CONCLUSIONS
  ViewGum© proved to be a reliable and discriminative tool to opto-electronically assess chewing efficiency, given an elastic specimen is chewed for 20 cycles and could be recommended for the evaluation of chewing efficiency in a clinical and research setting.
  
  
  CONCLUSIONS
  Chewing is a complex function of the oro-facial structures and the central nervous system. The application of the proposed assessments of the chewing function in geriatrics or special care dentistry could help visualising oro-functional or dental comorbidities in dysphagic patients or those suffering from protein-energy malnutrition.
authors.affiliation: Division of Gerodontology, School of Dental Medicine, University of Bern, Freiburgstrasse 7, 3010 Bern, Switzerland; Division of Gerodontology and Removable Prosthodontics, Dental University Clinic, University of Geneva, rue Barthélemy-Menn 19, 1205 Geneva, Switzerland. Electronic address: martin.schimmel@zmk.unibe.ch.
authors.forename: Martin
authors.initials: M
authors.lastname: Schimmel
authors.affiliation: Private Practice of Orthodontics, Ch de la Caroline 18 A, 1213 Petit Lancy, Geneva, Switzerland. Electronic address: slowdent@yahoo.com.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Christou
authors.affiliation: Division of Preventive Dentistry, Department of Oral Health Science, Graduate School of Medical and Dental Sciences, Niigata University, 2-5274, Gakkocho-Dori, Chuo-ku, 951-8514 Niigata, Japan. Electronic address: hideomiy@dent.niigata-u.ac.jp.
authors.forename: Hideo
authors.initials: H
authors.lastname: Miyazaki
authors.affiliation: Department of Orthodontics, School of Dentistry, University of Athens, 2 Thivon Street, 11527 Goudi, Athens, Greece. Electronic address: dhal@dhal.com.
authors.forename: Demetrios
authors.initials: D
authors.lastname: Halazonetis
authors.affiliation: Department of Internal Medicine, Rehabilitation and Geriatrics, University Hospitals of Geneva, Chemin du Pont Bochet, 1226 Thônex, Switzerland. Electronic address: francois.herrmann@hcuge.ch.
authors.forename: François R
authors.initials: FR
authors.lastname: Herrmann
authors.affiliation: Division of Gerodontology and Removable Prosthodontics, Dental University Clinic, University of Geneva, rue Barthélemy-Menn 19, 1205 Geneva, Switzerland; Department of Internal Medicine, Rehabilitation and Geriatrics, University Hospitals of Geneva, Chemin du Pont Bochet, 1226 Thônex, Switzerland. Electronic address: frauke.mueller@unige.ch.
authors.forename: Frauke
authors.initials: F
authors.lastname: Müller
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003124:Colorimetry / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008409:Mastication; D055815:Young Adult
keywords: Chewing gum; Edentulous mouth; Mastication; Symptom assessment