title: A new electroneurography as a prognostic tool for marginal mandibular nerve paralysis after parotid gland surgery: A preliminary evaluation.
abstract: OBJECTIVE
  Marginal mandibular nerve paralysis is the most frequent complication of benign parotid tumor surgery and results in cosmetic deformity. The purpose of this study was to develop a new electroneurography method for marginal mandibular nerve paralysis using electroneurography (ENoG) and judge its usefulness for clinical practice.
  
  
  METHODS
  Twenty-seven patients who underwent surgery for benign parotid tumor were enrolled. We proposed and use the mandibular angle method, in which the recording electrode was placed on the skin above the depressor anguli oris muscle while the reference electrode was placed on the skin of the parietal region, and percutaneous electrical stimulation was applied to enclose the mandibular angle that could measure the function of the marginal mandibular nerve solely. Preoperative and postoperative ENoG values were compared in paralytic and non-paralytic patients.
  
  
  RESULTS
  The mean postoperative ENoG value (35.0%) was lower than the preoperative value (90.5%) in paralytic patients, whereas no difference was observed between preoperative (79.3%) and postoperative (69.5%) ENoG values in non-paralytic patients.
  
  
  CONCLUSIONS
  A new ENoG method (mandibular angle method) was thought to reflect marginal mandibular nerve injury and might be useful for determining the likelihood of paralysis.
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, Osaka Medical College, Takatsuki, Japan. Electronic address: hagi@osaka-med.ac.jp.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Haginomori
authors.affiliation: Clinical Examination Department, Kagawa Prefectural University of Health Science, Takamatsu, Japan.
authors.forename: Shin-Ichi
authors.initials: SI
authors.lastname: Wada
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, Osaka Medical College, Takatsuki, Japan.
authors.forename: Takahiro
authors.initials: T
authors.lastname: Ichihara
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, Osaka Medical College, Takatsuki, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Terada
authors.affiliation: Department of Otolaryngology - Head & Neck Surgery, Osaka Medical College, Takatsuki, Japan.
authors.forename: Ryo
authors.initials: R
authors.lastname: Kawata
mesh_terms: D000328:Adult; D000368:Aged; D004558:Electric Stimulation; D005158:Facial Paralysis / Q000175:diagnosis* / Q000209:etiology; D005260:Female; D006801:Humans; D008340:Mandibular Nerve; D008875:Middle Aged; D010306:Parotid Gland / Q000601:surgery; D010307:Parotid Neoplasms / Q000601:surgery*; D011183:Postoperative Complications / Q000175:diagnosis*; D011379:Prognosis; D061221:Trigeminal Nerve Injuries / Q000150:complications / Q000175:diagnosis*
keywords: Electroneurography (ENoG); Marginal mandibular nerve paralysis; Parotid tumor; Prognosis; Surgical complication