Orthodontic treatment need of 9, 12 and 15 year-old children according to the Index of Orthodontic Treatment Need and the Dental Aesthetic Index

Abstract

Objective: To assess the differences in occlusal features in three cohorts at 9, 12 and 15 years of age, and compare orthodontic treatment need measured by the Dental Aesthetic Index (DAI) and Index of Orthodontic Treatment Need (IOTN). Design: Cross-sectional study. Setting: School of Dentistry, University of Valencia. Subjects: A total of 1086 children: 321 aged 9, 397 aged 12 and 368 aged 15. Methods: Children were examined to measure their orthodontic treatment need according to IOTN and DAI. The main outcome measure was orthodontic treatment need according to the DAI and IOTN indices. Results: Overbite and inter-incisal diastema were the occlusal features that presented significant differences between the three groups, diminishing with age. Treatment need according to the IOTN was 15.4% at 9 years, 20.9% at 12 years and 12.8% at 15 years. Treatment need according to DAI was 44.8% at 9 years, 21.7% at 12 years and 14.1% at 15 years. The diagnostic agreement between the two indices on the treatment need by age group was very low at 9 years (Kappa 0.18) and moderate at 12 and 15 years (Kappa 0.451 and 0.405, respectively). Conclusions: Orthodontic treatment need is greater in the mixed dentition and falls slightly as the child grows. The greatest variation in results between 9 and 15 years were found in relation to the DAI, which is consequently not recommended for use in the mixed dentition.

Key words:

• Children
• Dental Aesthetic Index
• Epidemiology
• Index of Orthodontic Treatment Need
• Orthodontic treatment need

Acknowledgements

This work was funded by project PI12/02570, part of the 2008–2011 Spanish National R&D&I Plan, and co-funded by the Evaluation Subdirectorate of the Instituto de Salud Carlos III (ISCIII) and by the European Regional Development Fund (ERDF). The manuscript was translated into English by Mary-Georgina Hardinge.

Disclaimer statements

Contributors Montserrat Boronat-Catalá did the explorations and wrote the draft. Carlos Bellot-Arcís and José María Montiel-Company designed and developed tools for analysing data and did the statistics. Montserrat Catalá-Pizarro and José Manuel Almerich-Silla designed the investigation and helped in writing draft. Guarantor: José Manuel Almerich-Silla.

Funding This work was funded by the 2008-2011 Spanish National R&D&I Plan, and co-funded by the Evaluation Subdirectorate of the Instituto de Salud Carlos III (ISCIII) and by the European Regional Development Fund (ERDF) [PI12/02570].

Conflicts of interest No conflicts-of-interest.

Ethics Approval The research was approved by the Human Research Ethics Committee of the University of Valencia (registration number H1372162226937).