title: Quantification of facial motion for objective evaluation using a high-speed three-dimensional face measurement system--a pilot study.
abstract: OBJECTIVE
  To estimate asymmetry in normal and pathological facial functions using an established computer generated objective evaluation technique.
  
  
  METHODS
  Analysis was performed on three-dimensional (3-D) data captured using a specially designed 3-D face shape measurement system. Six healthy volunteers and six patients with Bell's palsy were analyzed for forced eye closure and grinning actions. The asymmetry was computed at locations that had the greatest effect in each action on both the left and right sides of the face, in reference to a relaxed condition. The patients' data were captured and analyzed repeatedly for a period of three days for an average interval of four weeks, and the results were compared with the Yanagihara scale.
  
  
  RESULTS
  The control set of a normal sample exhibited a low standard deviation and a high correlation coefficient in both facial actions, and this contributed to a robust evaluation. The patients showed a higher standard deviation than the healthy subjects because of the larger degree of scatter of the data points in their respective data distributions. During the three clinical examinations, our proposed quantification method produced a continuous grading scheme, as opposed to the discrete scheme of the House-Brackmann grading.
  
  
  CONCLUSIONS
  Our proposed system shows advantages over the existing methods in that it does not rely on reference points nor does it use markers to analyze facial deformation. In addition, our estimations are very robust and accurate because our approach directly evaluates 3-D spatial variations in normal and pathological facial functions.
authors.affiliation: Department of Otorhinolaryngology, Nagoya University Graduate School of Medicine, Tsurumai-cho Showa-ku Nagoya, Japan. seisay@med.nagoya-u.ac.jp
authors.forename: Seiichi
authors.initials: S
authors.lastname: Nakata
authors.forename: Yukio
authors.initials: Y
authors.lastname: Sato
authors.forename: Pujitha
authors.initials: P
authors.lastname: Gunaratne
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Suzuki
authors.forename: Saiko
authors.initials: S
authors.lastname: Sugiura
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nakashima
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D020330:Bell Palsy / Q000503:physiopathology*; D016022:Case-Control Studies; D005145:Face / Q000502:physiology / Q000503:physiopathology*; D005154:Facial Nerve; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008432:Mathematical Computing; D008875:Middle Aged; D009068:Movement; D010865:Pilot Projects; D012016:Reference Values