title: Validity and reliability of a Self-Implementable method to evaluate masticatory performance: use of color-changeable chewing gum and a color scale.
abstract: OBJECTIVE
  The objective of this study was to confirm the validity of a Self-Implementable method to evaluate masticatory performance using a newly developed color scale and color-changeable chewing gum.
  
  
  METHODS
  We developed a dedicated color scale that enables anyone to easily check the color of the chewing gum instead of using specialist equipment. To examine the reliability of evaluating the masticatory performance by the subjects themselves, three groups of six subjects were recruited: a group of dentists, a group of adults and a group of elderly adults were asked to check the colors of the chewed samples using the color scale. The correlation between the use of the color scale and the use of a colorimeter to determine the color of the chewing gum was studied to confirm the validity of the color scale. To assess the reliability, intraclass correlation coefficients (ICCs) were determined.
  
  
  RESULTS
  A strong correlation was found between the a* value measured by the colorimeter and the mean scores from the color scale. The ICCs for intra-examiner and inter-examiner consistency were more than 0.88 for all three groups.
  
  
  CONCLUSIONS
  This research confirmed the validity and reliability of colorimetric analysis of color-changeable chewing gum using a color scale as a Self-Implementable method of evaluating masticatory performance.
authors.affiliation: Complete Denture Prosthodontics, Department of Masticatory Function Rehabilitation, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8549, Japan. m.nakamura.ore@tmd.ac.jp
authors.forename: Miho
authors.initials: M
authors.lastname: Kamiyama
authors.forename: Manabu
authors.initials: M
authors.lastname: Kanazawa
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Fujinami
authors.forename: Shunsuke
authors.initials: S
authors.lastname: Minakuchi
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002638:Chewing Gum; D003116:Color; D003124:Colorimetry / Q000379:methods*; D005505:Food Coloring Agents; D006801:Humans; D008409:Mastication / Q000502:physiology*; D015588:Observer Variation; D015203:Reproducibility of Results; D016353:Self-Examination / Q000379:methods*; D055815:Young Adult
chemical_list: D002638:Chewing Gum; D005505:Food Coloring Agents