title: Quantitative analysis of facial palsy using a three-dimensional facial motion measurement system.
abstract: OBJECTIVE
  The prognosis for facial nerve palsy (FNP) depends on its severity. Currently, many clinicians use the Yanagihara, House-Brackmann, and/or Sunnybrook grading systems to assess FNP. Although these assessments are performed by experts, inter- and intra-observer disagreements have been demonstrated. The quantitative and objective analyses of the degree of FNP would be preferred to monitor functional changes and to plan and evaluate therapeutic interventions in patients with FNP. Numerous two-dimensional (2-D) assessments have been proposed, however, the limitations of 2-D assessment have been reported. The purpose of this study was to introduce a three-dimensional (3-D) image generation system for the analysis of facial nerve palsy (FNP) and to show the correlation between the severity of FNP assessed by this method and two conventional systems.
  
  
  METHODS
  Five independent facial motions, resting, eyebrow raise, gentle eye closure, full smile with lips open and whistling were recorded with our system and the images were then analyzed using our software. The regional and gross facial symmetries were analyzed. The predicted scores were calculated and compared to the Yanagihara and H-B grading scores. We analyzed 15 normal volunteers and 42 patients with FNP.
  
  
  RESULTS
  The results showed that 3-D analysis could measure mouth movement in the anteroposterior direction, whereas two-dimensional analysis could not. The system results showed good correlation with the clinical results from the Yanagihara (r(2)=0.86) and House-Brackmann (r(2)=0.81) grading scales.
  
  
  CONCLUSIONS
  This objective method can produce consistent results that align with two conventional systems. Therefore, this method is ideally suited for use in a routine clinical setting.
authors: Department of Otolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya 467-0001, Japan.
authors: Sachiyo
authors: S
authors: Katsumi
authors: Department of Otolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya 467-0001, Japan; Department of Virology, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, Nagoya 466-8550, Japan. Electronic address: sesaki@med.nagoya-cu.ac.jp.
authors: Shinichi
authors: S
authors: Esaki
authors: Department of Electronics and Information Engineering, College of Engineering, Chubu University, 1200, Matsumoto-cho, Kasugai, Aichi 487-8501, Japan.
authors: Koosuke
authors: K
authors: Hattori
authors: Department of Otolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya 467-0001, Japan.
authors: Koji
authors: K
authors: Yamano
authors: Department of Electrical and Computer Engineering, Nagoya Institute of Technology, Bld. 19 #213, Gokiso-cho, Showa-ku, Nagoya, Aichi 466-8555, Japan.
authors: Taizo
authors: T
authors: Umezaki
authors: Department of Otolaryngology, Head and Neck Surgery, Nagoya City University Graduate School of Medical Sciences and Medical School, Kawasumi 1, Mizuho-cho, Mizuho-ku, Nagoya 467-0001, Japan.
authors: Shingo
authors: S
authors: Murakami
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D020330:Bell Palsy / Q000503:physiopathology*; D016022:Case-Control Studies; D005158:Facial Paralysis / Q000503:physiopathology*; D005260:Female; D016697:Herpes Zoster Oticus / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D012984:Software; D055815:Young Adult
keywords: Facial nerve palsy; House–Brackmann grading scale; Three-dimensional analysis; Yanagihara grading scale