title: Degeneration of fungiform and circumvallate papillae following molar extraction in rats.
abstract: OBJECTIVE
  Proper occlusion facilitates food intake and gustatory function is indispensable for the enjoyment of food. Although an interaction between dentoalveolar and gustatory afferent neurons has been suggested by previous studies, the relationship between occlusion and gustation remains unclear. This study investigated the effect of upper molar extraction which diminished occlusal support on peripheral gustatory receptors in rats.
  
  
  METHODS
  Thirty-six 7-week-old male Wistar rats were randomly assigned to either the experimental or the control group. All maxillary molars were extracted from rats in the experimental group under anesthesia, while a sham operation was conducted in the control group. The rats were euthanized 7, 14 or 28 days after the procedure. The morphology of the circumvallate papillae and taste buds using immunohistochemical methods and the fungiform papillae were visualized with 1% methylene blue.
  
  
  RESULTS
  Defects in the gustatory epithelium were observed after maxillary molar extraction. Rats in the experimental group had significantly fewer fungiform papillae, narrower circumvallate papillae, shallower trench depth, smaller trench area, smaller taste bud area, lower ratios of taste bud area to trench area and fewer taste buds than those in the control group.
  
  
  CONCLUSIONS
  The findings indicate that molar extraction would affect peripheral gustatory receptors. This is the first study to characterize changes in rat fungiform and circumvallate papillae after maxillary molar extraction. This study suggests a possible synergic relationship between dentoalveolar perception and gustatory function, which has clinical implications that occlusion is closely correlated with gustatory perception.
authors.affiliation: Department of Orthodontic Science, Graduate School of Medical and Dental Science, Tokyo Medical and Dental University (TMDU) , Yushima, Tokyo , Japan.
authors.forename: Jui-Chin
authors.initials: JC
authors.lastname: Hsu
authors.forename: Ippei
authors.initials: I
authors.lastname: Watari
authors.forename: Rieko
authors.initials: R
authors.lastname: Ono
authors.forename: Jutiporn
authors.initials: J
authors.lastname: Privatananupunt
authors.forename: Mariko
authors.initials: M
authors.lastname: Mizumachi-Kubono
authors.forename: Koji
authors.initials: K
authors.lastname: Honda
authors.forename: Yuji
authors.initials: Y
authors.lastname: Ishida
authors.forename: Takashi
authors.initials: T
authors.lastname: Ono
mesh_terms: D000818:Animals; D004396:Coloring Agents; D004848:Epithelium / Q000473:pathology; D007150:Immunohistochemistry; D053533:Keratin-8 / Q000032:analysis; D008297:Male; D008437:Maxilla / Q000601:surgery; D008751:Methylene Blue; D023421:Models, Animal; D008963:Molar / Q000601:surgery*; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013649:Taste / Q000502:physiology; D013650:Taste Buds / Q000473:pathology*; D014059:Tongue / Q000294:innervation / Q000473:pathology; D014081:Tooth Extraction / Q000379:methods*
chemical_list: D004396:Coloring Agents; D053533:Keratin-8; D008751:Methylene Blue
keywords: cytokeratin 8; immunohistochemistry; taste