title: Non-syndromic and syndromic keratocystic odontogenic tumors: systematic review and meta-analysis of recurrences.
abstract: BACKGROUND
  Keratocystic odontogenic tumors (KCOTs) are locally aggressive benign tumors which occur in the bones of both jaws with a high recurrence rate. The aim of the present study was to define and evaluate the post-treatment recurrence of KCOT lesions in non-syndromic and syndromic patients.
  
  
  METHODS
  A systematic review of the literature and meta-analysis was conducted according to the PRISMA statement. Seven electronic databases were searched from their start up to August 2013 for clinical studies on human patients without limitation to year, language or publication status.
  
  
  RESULTS
  A total of five case series studies with 323 treated KCOT lesions were included in the quantitative synthesis. The recurrence rate of KCOTs for three treatment forms ranged from 7% to 28%. Comparisons among the various treatments suggest that resection or marsupialization might be associated with fewer recurrences. However, high risk of bias and effect imprecision preclude the making of clinical recommendation. Existing evidence regarding nevoid basal cell carcinoma patients was likewise scarce.
  
  
  CONCLUSIONS
  The absence of studies with low risk of bias precludes the making of safe recommendations about the optimal management of KCOTs.
authors.affiliation: Department of Periodontology and Geriatric Dentistry, Institute of Dentistry, University of Oulu, FI-90014 Oulu, Finland.
authors.forename: Georgios N
authors.initials: GN
authors.lastname: Antonoglou
authors.affiliation: Oulu University Hospital, Department of Oral and Maxillofacial Surgery, Institute of Dentistry, University of Oulu, FI-90014 Oulu, Finland; BioMediTech, Institute of Biosciences and Medical Technology, University of Tampere, Finland. Electronic address: george.sandor@oulu.fi.
authors.forename: George K
authors.initials: GK
authors.lastname: Sándor
authors.affiliation: Advanced Education Program in Periodontology, University of Minnesota, 515 Delaware Street SE, Minneapolis, MN 55455, USA.
authors.forename: Vasiliki P
authors.initials: VP
authors.lastname: Koidou
authors.affiliation: Department of Orthodontics, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; Department of Oral Technology, School of Dentistry, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany; Clinical Research Unit 208, University of Bonn, Welschnonnenstr. 17, 53111 Bonn, Germany.
authors.forename: Spyridon N
authors.initials: SN
authors.lastname: Papageorgiou
mesh_terms: D001478:Basal Cell Nevus Syndrome / Q000473:pathology / Q000601:surgery; D015982:Bias; D003131:Combined Modality Therapy; D006801:Humans; D007573:Jaw Neoplasms / Q000473:pathology* / Q000601:surgery; D009364:Neoplasm Recurrence, Local / Q000473:pathology*; D009808:Odontogenic Tumors / Q000473:pathology* / Q000601:surgery; D013577:Syndrome
keywords: Basal cell nevus syndrome; Gorlin–Goltz syndrome; KCOT; Keratocystic odontogenic tumor; Recurrence