title: Prevalence of second premolar hypodontia in the Polish cleft lip and palate population.
abstract: BACKGROUND
  Cleft lip and/or palate is the most frequent congenital abnormality occurring in the craniofacial region and is often associated with numerous dental defects such as tooth agenesis, supernumerary teeth, microdontia, taurodontism, crown malformations, or delay in eruption. The prevalence of hypodontia in cleft-affected patients is much higher in comparison with a healthy population. The aim of this study was to evaluate the prevalence of second premolar hypodontia in patients with cleft lip and/or palate.
  
  
  METHODS
  We performed a retrospective, evaluation of panoramic radiographs and dental casts in the Department of Dentofacial Orthopeadics and Orthodontics, Wroclaw Medical University. Two independent observers evaluated the records of 469 patients with various types of clefts and analyzed dental casts and panoramic radiographs.
  
  
  RESULTS
  202 individuals met inclusion criteria. The sample comprised 120 UCLP patients, 38 BCLP patients, 28 CP patients, and 17 CLA patients. Hypodontia in the premolar region was observed in 39 individuals (19.3%). A total number of 58 second premolars were missing, of which 35 were maxillary second premolars (U5) and 23 were mandibular second premolars (L5).
  
  
  CONCLUSIONS
  Estimated hypodontia in the Polish CL/P sample was considerably higher than the hypodontia in permanent dentition reported for a European healthy population. The number of congenitally missing second premolars was higher in the maxillary arch than in the mandibular.
authors.affiliation: Department of Dentofacial Orthopedics and Orthodontics, Division of Facial Abnormalities, Wrocław Medical University, Wrocław, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Mikulewicz
authors.affiliation: Department of Dentofacial Orthopedics and Orthodontics, Division of Facial Abnormalities, Wrocław Medical University, Wrocław, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Ogiński
authors.affiliation: Department of Orthodontics, Technische Universität, Dresden, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Gedrange
authors.affiliation: Department of Orthodontics, University of Szeged, Szeged, Hungary.
authors.forename: Adam
authors.initials: A
authors.lastname: Berniczei-Royko
authors.affiliation: Department of Management in Health Care, University of Medical Sciences, Poznań, Poland.
authors.forename: Elżbieta
authors.initials: E
authors.lastname: Prussak
mesh_terms: D000848:Anodontia / Q000150:complications* / Q000453:epidemiology*; D001641:Bicuspid / Q000002:abnormalities*; D002675:Child, Preschool; D002971:Cleft Lip / Q000150:complications* / Q000453:epidemiology*; D002972:Cleft Palate / Q000150:complications* / Q000453:epidemiology*; D005260:Female; D006801:Humans; D008297:Male; D011044:Poland / Q000453:epidemiology; D015995:Prevalence; D020390:Tooth Socket / Q000002:abnormalities