title: Prevalence of ciliated epithelium in apical periodontitis lesions.
abstract: BACKGROUND
  This article reports on the morphologic features and the frequency of ciliated epithelium in apical cysts and discusses its origin.
  
  
  METHODS
  The study material consisted of 167 human apical periodontitis lesions obtained consecutively from patients presenting for treatment during a period of 12 years in a dental practice operated by one of the authors. All of the lesions were obtained still attached to the root apices of teeth with untreated (93 lesions) or treated canals (74 lesions). The former were obtained by extraction and the latter by extraction or apical surgery. Specimens were processed for histopathologic and histobacteriologic analyses. Lesions were classified, and the type of epithelium, if present, was recorded.
  
  
  RESULTS
  Of the lesions analyzed, 49 (29%) were diagnosed as cysts. Of these, 26 (53%) were found in untreated teeth, and 23 (47%) related to root canal-treated teeth. Ciliated columnar epithelium was observed partially or completely lining the cyst wall in 4 cysts, and all of them occurred in untreated maxillary molars. Three of these lesions were categorized as pocket cysts, and the other was a true cyst.
  
  
  CONCLUSIONS
  Ciliated columnar epithelium-lined cysts corresponded to approximately 2% of the apical periodontitis lesions and 8% of the cysts of endodontic origin in the population studied. This epithelium is highly likely to have a sinus origin in the majority of cases. However, the possibility of prosoplasia or upgraded differentiation into ciliated epithelium from the typical cystic lining squamous epithelium may also be considered.
authors.affiliation: Private practice, Cetraro, Italy. Electronic address: dricucci@libero.it.
authors.forename: Domenico
authors.initials: D
authors.lastname: Ricucci
authors.affiliation: Private practice, Cetraro, Italy.
authors.forename: Simona
authors.initials: S
authors.lastname: Loghin
authors.affiliation: Department of Endodontics, Faculty of Dentistry, Estácio de Sá University, Rio de Janeiro, RJ, Brazil.
authors.forename: José F
authors.initials: JF
authors.lastname: Siqueira
authors.affiliation: Department of Oral Diagnostic Sciences, Georgia Regents University College of Dental Medicine, Augusta, Georgia.
authors.forename: Rafik A
authors.initials: RA
authors.lastname: Abdelsayed
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018441:Biofilms; D002454:Cell Differentiation; D002923:Cilia / Q000473:pathology; D003751:Dental Fistula / Q000382:microbiology / Q000473:pathology; D004847:Epithelial Cells / Q000473:pathology; D004848:Epithelium / Q000473:pathology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010482:Periapical Abscess / Q000382:microbiology / Q000473:pathology; D010484:Periapical Granuloma / Q000473:pathology; D010485:Periapical Periodontitis / Q000473:pathology*; D011842:Radicular Cyst / Q000473:pathology; D019227:Tooth Apex / Q000473:pathology; D019553:Tooth, Nonvital / Q000473:pathology; D055815:Young Adult
keywords: Apical cyst; apical periodontitis lesion; ciliated epithelium; metaplasia; prosoplasia