title: Prevalence of congenital dental anomalies in the primary dentition in Taiwan.
abstract: OBJECTIVE
  The purpose of this study was to investigate the prevalence of congenital anomolies in the primary dentition in preschool Taiwanese children compared to Caucasion populations.
  
  
  METHODS
  The study group comprised 2,611 children (1,442 boys ond 1,169 girls) between 2 and 6 years-old in the primary dentition phase using a random sampling technique. The presence of hypodontia, hyperdontia, and double teeth (fusion ond gemination) were recorded ond analyzed using Fisher's exact test.
  
  
  RESULTS
  The prevalence of hypodontia was approximately 2%. Unilaterol missing teeth were more frequently observed than bilateral missing teeth. The primary mandibular right lateral incisor was the most frequently missing tooth. The prevalence af hyperdontia was less than 1%. All of the supernumerary teeth were located in the primary maxillary incisor area. The prevalence of double teeth was approximately 3%. All double teeth were located in the anterior region, and most of them were found in the mandibular lateral incisor and canine area. There were no differences in the prevalence of anomalies between the sexes.
  
  
  CONCLUSIONS
  The prevalence of hypodontia and double teeth, but not hyperdontia, was significantly higher in Taiwanese children vs Caucasian children. Early detection of primary dental anomalies may help prevent oral disease in children.
authors.affiliation: Buddhist Tzu Chi General Hospital, Taipei Branch, Taipei, Taiwan.
authors.forename: Yi-Horng
authors.initials: YH
authors.lastname: Chen
authors.forename: Nai-Chia
authors.initials: NC
authors.lastname: Cheng
authors.forename: Yi-Bing
authors.initials: YB
authors.lastname: Wang
authors.forename: Chin-Yuh
authors.initials: CY
authors.lastname: Yang
mesh_terms: D000848:Anodontia / Q000453:epidemiology; D044466:Asian People / Q000706:statistics & numerical data*; D002648:Child; D002675:Child, Preschool; D005260:Female; D007839:Functional Laterality; D005671:Fused Teeth / Q000453:epidemiology; D006801:Humans; D008297:Male; D015995:Prevalence; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology; D014071:Tooth Abnormalities / Q000453:epidemiology*; D014094:Tooth, Deciduous / Q000002:abnormalities*; D014096:Tooth, Supernumerary / Q000453:epidemiology; D044465:White People / Q000706:statistics & numerical data