title: Computerized objective measurement of facial motion: normal variation and test-retest reliability.
abstract: OBJECTIVE
  Objective quantitative measurements of facial motion for the assessment of outcomes in patients with facial paralysis have been elusive. This paper will reintroduce an objective computerized program for measurement of facial motion and present data on symmetry in healthy subjects and test-retest reliability in patients with facial paralysis.
  
  
  METHODS
  Cross-sectional analysis of archived images.
  
  
  METHODS
  Tertiary referral center.
  
  
  METHODS
  Good quality video-recordings of 38 healthy subjects and 30 facial paralysis subjects with a wide range of paralysis that had been tested twice were selected.
  
  
  METHODS
  Using image subtraction techniques of digital video recordings, computer-generated strength-duration curves of prescribed facial movements were automatically constructed.
  
  
  METHODS
  The areas under the curve for specific regions of each side of the face were compared as a proportion described as a percentage (left/right in healthy subjects, abnormal/normal side in paralysis) in which 100% would be perfect symmetry.
  
  
  RESULTS
  Thirty-eight healthy subjects had the following left/right symmetry means (95% confidence interval): brow, 98.95 (93.94-103.95); eye, 99.18 (96.31-102.06); and mouth, 96.87 (93.10-100.63).Thirty patients with varying degrees of facial paralysis, tested twice, were evaluated to determine the degree of agreement between trials as measured by the intraclass correlation coefficient. The results showed the intraclass correlation coefficient (95% confidence interval) for brow was 0.972 (0.943-0.987), eye 0.950 (0.898-0.976), and mouth 0.951 (0.901-0.976).
  
  
  CONCLUSIONS
  These results demonstrate no substantial side bias in healthy subjects and excellent test-retest reliability in patients with facial paralysis. This program may be made available for interested investigators upon request.
authors: Facial Nerve Center, Department of Otolaryngology-Head and Neck Surgery, Washington University School of Medicine, St. Louis, Missouri 63110, USA. jgneely@aol.com
authors: John Gail
authors: JG
authors: Neely
authors: Katie X
authors: KX
authors: Wang
authors: Chelsea A
authors: CA
authors: Shapland
authors: Ali
authors: A
authors: Sehizadeh
authors: Amy
authors: A
authors: Wang
mesh_terms: D003627:Data Interpretation, Statistical; D016208:Databases, Factual; D005145:Face / Q000502:physiology*; D005158:Facial Paralysis / Q000175:diagnosis; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D009068:Movement / Q000502:physiology*; D012016:Reference Values; D015203:Reproducibility of Results; D013060:Speech; D014743:Videotape Recording