title: Morphology of human fungiform papillae after severing chorda tympani nerve.
abstract: OBJECTIVE
  We aimed to clarify the postoperative morphology of the fungiform papillae (FP) of the tongue in patients who recovered gustatory function after the chorda tympani nerve was severed during middle ear surgery.
  
  
  METHODS
  Fifty-four patients with normal preoperative gustatory function measured by electrogustometry (EGM) were included. The proximal and distal stumps of the severed nerves were re-adapted or re-approximated during surgery to promote regeneration of the nerve. The EGM thresholds over 2 years after surgery were compared with preoperative values. At the same time, the morphological characteristics of the FP in the midlateral region of the tongue were recorded with a digital microscope.
  
  
  RESULTS
  One month after surgery, EGM showed no response in any patients. At a time point of more than 2 years, the FP showed complete atrophy and no response to EGM on the surgical side in 21 of the 54 patients. In 16 patients who showed complete recovery of the EGM threshold (below 20 microA), the FP showed an almost normal appearance, and the mean number of FP was 77.5% (10 +/- 4.1 papillae per square centimeter) of that on the contralateral side (12.9 +/- 4.9 papillae per square centimeter; p > 0.05).
  
  
  CONCLUSIONS
  The morphology of the FP was maintained in patients who recovered gustatory function after the chorda tympani nerve was severed. Because the results indicate regeneration of the taste buds, further observation is needed to detect regenerated taste buds in the FP.
authors.affiliation: Department of Otolaryngology-Head and Neck Surgery, Faculty of Medicine, University of Fukui, Fukui, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Saito
authors.forename: Norihiko
authors.initials: N
authors.lastname: Narita
authors.forename: Takechiyo
authors.initials: T
authors.lastname: Yamada
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Manabe
authors.forename: Tetsufumi
authors.initials: T
authors.lastname: Ito
mesh_terms: D000328:Adult; D018424:Cholesteatoma, Middle Ear / Q000601:surgery; D002814:Chorda Tympani Nerve / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D009416:Nerve Regeneration / Q000502:physiology*; D020127:Recovery of Function; D012189:Retrospective Studies; D013649:Taste / Q000502:physiology*; D013650:Taste Buds / Q000033:anatomy & histology* / Q000502:physiology