title: Evaluation of reliability of perioral muscle pressure measurements using a newly developed device with a lip piece.
abstract: OBJECTIVE
  We examined the reliability of measurements using a newly developed perioral muscle pressure measuring device with a lip piece in healthy adults.
  
  
  METHODS
  Subjects were 40 healthy men (25.8 years) with normal stomatognathic function. Perioral muscle pressure measuring device with a lip piece was used to measure upper lip, lower lip and tongue pressure, and a balloon-based measurement device was used to measure tongue and cheek pressure. Each measurement was taken twice with a 1-min interval between the two measurements. We determined intra-rater reliability by using the intra-class correlation coefficient as a test of relative reliability. As a test of absolute reliability, Bland-Altman analysis was used to assess systematic bias and the 95% confidence interval of the minimal detectable change was calculated. Additionally, the coefficient of variation was calculated. The Spearman-Brown formula was calculated the number of measurements needed to achieve a confidence coefficient ≥0.9. Each set of measurements was followed by a second set that were taken 1 week later.
  
  
  RESULTS
  All measurements showed high values of intra-class correlation coefficient. Upper lip, tongue, and cheek pressure can be determined based on a single measurement, while lower lip pressure requires averaging twice. No systematic bias was observed. The coefficients of variation of measurements were almost the same between the two devices.
  
  
  CONCLUSIONS
  Measurements were highly reliable regardless of the type of perioral muscles. Our findings suggest that the method described in this study is useful as a quantitative chair side method for examining perioral muscle pressure.
authors.affiliation: Department of Removable Prosthodontics, The Nippon Dental University School of Life Dentistry at Niigata, Japan.|Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, Japan.
authors.forename: Mutsumi
authors.initials: M
authors.lastname: Takahashi
authors.affiliation: Department of Removable Prosthodontics, The Nippon Dental University School of Life Dentistry at Niigata, Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Koide
authors.affiliation: Department of Oral Function and Rehabilitation, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Suzuki
authors.affiliation: Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Satoh
authors.affiliation: Department of Physiology, The Nippon Dental University School of Life Dentistry at Niigata, Japan.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Iwasaki
mesh_terms: D000328:Adult; D006801:Humans; D008046:Lip / Q000502:physiology*; D008297:Male; D053581:Muscle Strength Dynamometer; D009132:Muscles / Q000502:physiology*; D011312:Pressure; D015203:Reproducibility of Results