title: Prevalence and distribution of hypodontia in a Turkish orthodontic patient population: results from a large academic cohort.
abstract: OBJECTIVE
  Purpose of this study is to investigate the prevalence and distribution of congenitally missing permanent teeth (CMT) in a Turkish orthodontic patient population.
  
  
  METHODS
  Panoramic radiographs, intraoral photographs and dental casts of 2761 patients (females 1677, males 1084) aged from 9 to 46 who underwent orthodontic treatment at Selcuk University Department of Orthodontics from 1990 to 2005 were retrospectively reviewed for CMT. A comprehensive chart review was conducted in all subjects. Patient and treatment-related data were registered in a computer database for comparative analysis.
  
  
  RESULTS
  When missing third molar data were included, prevalence of CMT in the overall population was 30.64% with no significant differences between male and female patients (p=0.546). On the other hand, prevalence of CMT excluding third molars was 6.77% with a significantly higher prevalence in females compared to male patients (7.63% vs. 5.44%, p=0.030). The most commonly congenitally missing tooth types in decreasing order were the third molars followed by maxillary lateral incisors and mandibular second premolars. The majority of missing third molars were located in the maxilla (55.7%) with no significant gender differences (p=0.334). 58.4% of CMT excluding third molars in females were located in the maxilla compared to only 40.8% in males (p=0.001). In both gender groups, majority of CMT excluding third molars were located in the anterior segment (55.6% and 58.4% in male and female patients respectively, p=0.713).
  
  
  CONCLUSIONS
  The most commonly congenitally missing tooth type is third molars followed by maxillary lateral incisors and mandibular second premolars in our population. Although there were no gender differences in prevalence and anatomical distribution of missing third molars, CMT excluding third molars was significantly more prevalent in females with predominantly maxillary distribution in our population.
authors.affiliation: ahutopkara@gmail.com
authors.forename: A
authors.initials: A
authors.lastname: Topkara
authors.forename: Z
authors.initials: Z
authors.lastname: Sari
mesh_terms: D000293:Adolescent; D000328:Adult; D000848:Anodontia / Q000453:epidemiology*; D001641:Bicuspid / Q000002:abnormalities; D002648:Child; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D008334:Mandible / Q000473:pathology; D008437:Maxilla / Q000473:pathology; D008875:Middle Aged; D003765:Models, Dental / Q000706:statistics & numerical data; D008964:Molar, Third / Q000002:abnormalities; D009971:Orthodontics, Corrective / Q000706:statistics & numerical data*; D023861:Photography, Dental / Q000706:statistics & numerical data; D015995:Prevalence; D011862:Radiography, Panoramic / Q000706:statistics & numerical data; D012189:Retrospective Studies; D012737:Sex Factors; D014421:Turkey / Q000453:epidemiology; D055815:Young Adult