Orthodontic treatment need and the dental aesthetic index

The Dental Aesthetic (DAI) was devised as a measure of dental appearance and based on lay opinions as opposed to professional assessments of need. The DAI is calculated from the weighted scores of ten occlusal variables. These same variables have been used in other malocclusion indices intended to measure morphological deviations from normality. It is, therefore, important to ask if the DAI might be used to screen both deviations of dental appearance and deviations of occlusion from accepted norms. The original DAI design was based on analysis data from permanent dentitions. However, a large percentage of orthodontic assessments are carried out in the mixed dentition. Therefore, the present study includes a sample of mixed dentitions to test the effectiveness of the DAI in this group. The DAI was tested against the subjective assessments of severity made by orthodontists. Sensitivity and negative predictive power were high. Performance in the mixed dentition group was slightly lower than the permanent dentition group. It is concluded that while the DAI is not sufficiently reliable for assessment of treatment need in the individual, its sensitivity and negative predictive power might provide a useful screening mechanism which reflects both the concerns of patients regarding appearance and the general treatment recommendations of orthodontists. Testing on much larger samples is now required.