title: Cytokeratin 14 and cytokeratin 18 expressions in reduced enamel epithelium and dentigerous cyst: Possible role in oncofetal transformation and histogenesis- of follicular type of adenomatoid odontogenic tumor.
abstract: BACKGROUND
  Odontogenic cysts and tumors arise from the structures and remnants associated with tooth development. Cysts and tumors derived from the odontogenic tissues constitute an unusually diverse group of lesions. This diversity reflects the complex development of the dental structures, since all these lesions originate through some alteration from the normal pattern of odontogenesis. Cytokeratin (CK) 14 is the typical intermediary filament of odontogenic epithelium, CK 18 is the major components of the intermediate filaments of simple or single layered epithelial tissue; it is not expressed in stratified squamous epithelium. The present study was undertaken to understand the expression pattern of these cytokeratins in dentigerous cyst, dental follicular tissue, adenomatoid odontogenic tumor (AOT) and unicystic ameloblastoma.
  
  
  METHODS
  The present study consists of 60 specimens consisting of 20 samples of Dentigerous cyst, 20 samples of Reduced enamel epithelium/dental follicles, 10 samples of Follicular type of AOT, 10 samples of unicystic ameloblastoma. The sections of these specimens were stained for CK 14 and CK 18. The number of cells positive for CK 14 and CK 18 was counted per 100 cells. The cells were counted in four randomly selected high-power fields and the mean was calculated. Scoring of cytokeratin 14 expressions was done using Remmele score.
  
  
  RESULTS
  The highest expression of cytokeratin 14 was noted in AOT, least was seen in dental follicle/Reduced enamel epithelium (REE). CK18 was negative in all the cases included in the present study.
  
  
  CONCLUSIONS
  In the present study, the expression of CK14 was noted in AOT, Dentigerous cyst (DC), Unicystic Ameloblastoma (UCA) and Dental follicle/REE. The expressions between these lesions were compared. These expression pattern may provide an insight to the histogenesis of AOT.
authors.affiliation: Department of Oral Pathology and Microbiology, Subbaiah Institute of Dental Sciences, Shimoga, Karnataka, India.
authors.forename: D K
authors.initials: DK
authors.lastname: Shruthi
authors.affiliation: Department of Anaesthesia, Subbaiah Institute of Medical Sciences, Shimoga, Karnataka, India.
authors.forename: M C
authors.initials: MC
authors.lastname: Shivakumar
authors.affiliation: Department of Oral Pathology and Microbiology, Coorg Institute of Dental Sciences, Virajpet, Karnataka, India.
authors.forename: Anand S
authors.initials: AS
authors.lastname: Tegginamani
authors.affiliation: Department of Oral Pathology, Rishiraj Dental College, Bhopal, Madhya Pradesh, India.
authors.forename: B
authors.initials: B
authors.lastname: Karthik
authors.affiliation: Department of Oral and Maxillofacial Surgery, Subbaiah Institute of Dental Sciences, Shimoga, Karnataka, India.
authors.forename: B I
authors.initials: BI
authors.lastname: Chetan
keywords: Adenomatoid odontogenic tumor; Cytokeratin 18; UnicysticAmeloblastoma; cytokeratin 14; dental follicle; dentigerous cyst; reduced enamel epithelium