title: Site-specificity of tooth agenesis in subjects with maxillary canine malpositions.
abstract: Tooth agenesis (hypodontia) was studied in two samples of nonsyndromic subjects possessing either maxillary canine-first premolar transposition (Mx.C.P1; N=43, M9:F34) or palatal displacement of the maxillary canine (PDC; N=58, M21:F37). Agenesis of permanent teeth was identified by x-ray film analysis. Significantly elevated tooth-agenesis frequencies were noted in both samples. Statistically significant differences between the Mx.C.P1 and PDC samples were found in locations of absent teeth, indicating site-specificity of tooth agenesis associated with these canine malpositions. In Mx.C.P1, agenesis of third molars (M3) occurred at a near-normal rate (19%) while maxillary lateral incisor (I2) agenesis showed a thirteen-fold increase (26%). In PDC, the prevalence rate for associated M3 agenesis was 40%, twice the normal rate, while I2 agenesis was 3%, a slight elevation of no statistical significance. These new findings may warrant a hypothesis of anteroposterior site-specific shift in the occurrence of tooth agenesis, associated genetically or epigenetically with distinct anomalies of maxillary canine position and possibly other abnormalities.
authors.affiliation: Department of Orthodontics, Harvard School of Dental Medicine, Boston, Mass., USA.
authors.forename: S
authors.initials: S
authors.lastname: Peck
authors.forename: L
authors.initials: L
authors.lastname: Peck
authors.forename: M
authors.initials: M
authors.lastname: Kataja
mesh_terms: D000293:Adolescent; D000848:Anodontia / Q000150:complications* / Q000235:genetics; D001641:Bicuspid / Q000002:abnormalities / Q000473:pathology; D002648:Child; D003481:Cuspid / Q000473:pathology*; D005260:Female; D006801:Humans; D007180:Incisor / Q000002:abnormalities; D008297:Male; D008437:Maxilla; D008964:Molar, Third / Q000002:abnormalities; D010159:Palate; D015995:Prevalence; D013045:Species Specificity; D014079:Tooth Eruption, Ectopic / Q000150:complications* / Q000235:genetics