title: Non-syndromic hypodontia in an Iranian orthodontic population.
abstract: To investigate the prevalence, characteristics (ie, malocclusion, location, type), and sex distribution of hypodontia in an Iranian orthodontic population. A retrospective study was conducted using periapical and panoramic radiographs and study models of 1,751 subjects attending university orthodontic clinics (870 females, 881 males, age 9-27 years). The Chi-square test was used to analyze differences in the distribution of hypodontia, after stratification by sex and malocclusion type. A total of 197 congenitally missing teeth were observed in 160 patients (9.1%; 74 boys and 86 girls); there were no statistically significant differences between sexes (Chi-square = 0.832, P = 0.36). Hypodontia was more common in patients with Class III malocclusion (45.2%), and was more prevalent in the maxilla (71%) than in the mandible (29%). Maxillary lateral incisors (35.6%) and maxillary second premolars (13.0%) were the most commonly missing teeth, followed by mandibular lateral incisors (9.6%) and mandibular second premolars (8.2%). The prevalence of missing teeth was higher in the anterior segment (incisors and canines) than in the posterior segment (premolars and molars). The prevalence of oligodontia was 0.34%. The prevalence and characteristics of the most frequently missing teeth accorded with the findings of most studies conducted in other countries.
authors.affiliation: Department of Orthodontics, School of Dentistry, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Elaheh
authors.initials: E
authors.lastname: Vahid-Dastjerdi
authors.forename: Ali
authors.initials: A
authors.lastname: Borzabadi-Farahani
authors.forename: Mina
authors.initials: M
authors.lastname: Mahdian
authors.forename: Nazila
authors.initials: N
authors.lastname: Amini
mesh_terms: D000293:Adolescent; D000328:Adult; D000848:Anodontia / Q000150:complications / Q000453:epidemiology*; D016009:Chi-Square Distribution; D002648:Child; D005260:Female; D006801:Humans; D007492:Iran / Q000453:epidemiology; D008297:Male; D008312:Malocclusion, Angle Class II / Q000150:complications; D008313:Malocclusion, Angle Class III / Q000150:complications; D015995:Prevalence; D012189:Retrospective Studies; D055815:Young Adult