title: Primary double teeth and their effect on permanent successors.
abstract: OBJECTIVE
  Understanding the effects of primary double tooth (PDT) on permanent successors is important to ensure healthy permanent occlusion and aesthetics. The aim of this study is to determine the prevalence and type of PDT, their effect on permanent successors, and the accompanying dental anomalies/pathologies in a Turkish population.
  
  
  METHODS
  Study design: The records of 63 PDTs in 54 healthy Caucasian children among 10,000 patients were investigated. PDTs were classified according to Aguilo's classification.
  
  
  RESULTS
  The prevalence of PDT was 0.6%. Of the 63 PDTs, 14.3% were type I, 11.1% were type II, 31.7% were type III, and 41.3% were type IV; one (1.6%) was a triple tooth. Aplasia of the permanent lateral incisor was observed most frequently in association with type I (56%) PDT. All PDTs associated with a supernumerary permanent tooth were type IV. Dental anomalies/pathologies such as odontoma, talon cusp were observed. Caries involvement was observed most frequently in type IV (58.3%) PDT.
  
  
  METHODS
  The chi-squared test was used to determine whether successor aplasia depended on PDT type, and contingency coefficients (%) were calculated to determine the degree of association between aplasia and PDT type.
  
  
  CONCLUSIONS
  Clinicians should assess PDT clinically and radiographically to determine whether they are associated with aplasia of permanent lateral incisors (type I) or supernumerary permanent teeth (type IV). Type IV of PDT should be sealed with sealant or resin.
authors.affiliation: Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, University of Ondokuz Mayis, Turkey.
authors.forename: A Z
authors.initials: AZ
authors.lastname: Zengin
authors.affiliation: Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, University of Ondokuz Mayis, Turkey.
authors.forename: P
authors.initials: P
authors.lastname: Celenk
authors.affiliation: Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, University of Ondokuz Mayis, Turkey.
authors.forename: K
authors.initials: K
authors.lastname: Gunduz
authors.affiliation: Faculty of Dentistry, Department of Oral and Maxillofacial Radiology, University of Ondokuz Mayis, Turkey.
authors.forename: M
authors.initials: M
authors.lastname: Canger
mesh_terms: D000848:Anodontia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D003731:Dental Caries / Q000453:epidemiology; D019229:Dentition, Permanent; D005260:Female; D005671:Fused Teeth / Q000453:epidemiology*; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D009810:Odontoma / Q000453:epidemiology; D015995:Prevalence; D012189:Retrospective Studies; D019228:Tooth Crown / Q000002:abnormalities; D014092:Tooth Root / Q000002:abnormalities; D014094:Tooth, Deciduous / Q000002:abnormalities*; D014096:Tooth, Supernumerary / Q000453:epidemiology; D014421:Turkey / Q000453:epidemiology