title: Age changes in orthodontic treatment need: a longitudinal study of 10- and 13-year-old children, using the Dental Aesthetic Index.
abstract: The Dental Aesthetic Index (DAI) was used to assess the prevalence of unmet orthodontic treatment need in 150 13-year-old schoolchildren in Dunedin, New Zealand, and to compare the findings with those obtained in the same children at 10 years of age. Fewer 13-year-olds (27%) had a "mandatory" need of orthodontic treatment than when they were 10 years old (33%), 20% had "no/little" need for orthodontic treatment, 33% had an "elective" need for treatment and 20% had a "desirable" need for treatment. The fall in DAI scores is attributed to over-sensitivity of the Index to mixed dentition traits. When the individual scores were analysed, only 7% of the 10-year-olds were given the same scores as when they were 13 years old, 52% were given higher scores and 41% were given lower scores. This disagreement between scores was masked to a limited extent by the DAI categories: 49% of the 10-year-olds were assigned to the same DAI category at 13 years of age, 20% to a greater treatment-need category and approximately 30% to a lower treatment-need category. The DAI, in common with other malocclusion indices, is unreliable over time because it is affected by developmental changes in the occlusal traits measured.
authors.affiliation: Jonathon.Chi@ahmg.com.au
authors.forename: J
authors.initials: J
authors.lastname: Chi
authors.forename: M
authors.initials: M
authors.lastname: Johnson
authors.forename: M
authors.initials: M
authors.lastname: Harkness
mesh_terms: D000293:Adolescent; D000367:Age Factors; D016009:Chi-Square Distribution; D002648:Child; D003724:Dental Arch / Q000473:pathology; D003818:Dentition, Mixed; D003970:Diastema / Q000473:pathology / Q000628:therapy; D004955:Esthetics, Dental; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008310:Malocclusion / Q000145:classification / Q000473:pathology / Q000628:therapy*; D008445:Maxillofacial Development; D020380:Needs Assessment; D009520:New Zealand; D015588:Observer Variation; D009971:Orthodontics, Corrective; D015203:Reproducibility of Results; D012737:Sex Factors