title: Dental anomaly patterns associated with tooth agenesis.
abstract: OBJECTIVE
  The objective of this study is to evaluate the relationship between tooth agenesis and the occurrence of other dental anomalies in children and adolescents.
  
  
  METHODS
  Panoramic radiographs of 195 subjects with tooth agenesis, except for the third molar, were retrospectively examined and compared with a non-agenesis control group of 600 subjects. Their ages ranged from 7 to 15 years. Panoramic and periapical radiographs were used to analyze the presence of other associated dental anomalies. The occurrences of these anomalies were compared with those in the non-agenesis group.
  
  
  RESULTS
  Subjects with tooth agenesis showed a significantly higher prevalence of a small maxillary lateral incisor (17.7%), distoangulation of the mandibular second premolar (6.5%), delayed development of a permanent tooth (10.8%), and hypo-occlusion of a primary molar (11.8%). In contrast, the prevalence of a supernumerary tooth was higher in the control group, and no difference was observed in the prevalence of ectopic eruption of a first molar. According to the agenesis area, microdontia of the maxillary lateral incisors occurred more often in patients with anterior or premolar agenesis than in the molar agenesis groups. Distoangulation of the mandibular second premolars, delayed tooth development, and hypo-occlusion of the primary molars were associated with premolar tooth agenesis.
  
  
  CONCLUSIONS
  A small maxillary lateral incisor, distoangulation of the mandibular second premolar, delayed development of a permanent tooth, and hypo-occlusion of a primary molar were frequently associated with tooth agenesis, providing additional evidence of a genetic interrelationship in the causes of these dental anomalies.
authors.affiliation: a Department of Pediatric Dentistry, College of Dentistry , Wonkwang University , Iksan , Republic of Korea.
authors.forename: Su Ji
authors.initials: SJ
authors.lastname: Choi
authors.affiliation: a Department of Pediatric Dentistry, College of Dentistry , Wonkwang University , Iksan , Republic of Korea.
authors.forename: Je Woo
authors.initials: JW
authors.lastname: Lee
authors.affiliation: a Department of Pediatric Dentistry, College of Dentistry , Wonkwang University , Iksan , Republic of Korea.
authors.forename: Ji Hyun
authors.initials: JH
authors.lastname: Song
mesh_terms: D000293:Adolescent; D000848:Anodontia / Q000000981:diagnostic imaging* / Q000453:epidemiology; D002648:Child; D003766:Dental Occlusion; D019229:Dentition, Permanent; D005260:Female; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D008963:Molar / Q000002:abnormalities / Q000000981:diagnostic imaging*; D011862:Radiography, Panoramic; D014071:Tooth Abnormalities / Q000000981:diagnostic imaging* / Q000453:epidemiology; D014079:Tooth Eruption, Ectopic / Q000000981:diagnostic imaging; D014096:Tooth, Supernumerary / Q000000981:diagnostic imaging
keywords: Genetic predisposition; hypodontia; panoramic radiograph; tooth abnormalities