A comparison between DAI and SCAN in estimating orthodontic treatment need.

This study was undertaken to assess the reliability and the correlation between two aesthetic indices, the Dental Aesthetic Index (DAI) and the Standardised Continuum of Aesthetic Need (SCAN Index) in estimating orthodontic treatment priority. The indices were applied to 53 randomly selected study models and records of orthodontic patients treated at Mount Vernon Hospital, Middlesex, UK. The patients ages at initial presentation ranged from 10.7 to 16.4 years (Mean 12.8 years, SD 1.0). The DAI and the SCAN Index were moderately correlated (r = 0.67) and the association was highly statistically significant (p < 0.001). The findings indicated that the two indices could be used consistently. The limitations of both indices are also discussed.