EVALUATION OF ORTHODONTIC TREATMENT USING THE DENTAL AESTHETIC INDEX

This investigation evaluates dental esthetic differences of orthodonti c patients before and after treatment. The orthodontic treatment provi ded for patients in this investigation involved the use of removable a ppliances in 85% of the cases, use of fixed appliances in 2% of the ca ses, and a combination of fixed and removable appliances in 13% of the cases. Records of patients treated at a dental school clinic between 1959 and 1984 were reviewed. Inclusion criteria for this study include d complete patient records, and the presence of dental casts for estim ation of the Dental Aesthetic Index (DAI). Of the 932 patients, 116 pa tient records were included. Fifty patients began treatment during the mixed dentition (age less-than-or-equal-to 144 months), and 66 were t reated during the permanent dentition (age > 144 months). Pretreatment DAI values and component factors were measured and compared with post treatment values. The DAI scores improved significantly (p less-than-o r-equal-to 0.0001) in both age groups (paired t test; Bonferroni corre ction). However, 20% of the patients showed a worsening or no change i n the DAI with treatment. In the mixed dentition group, maxillary ante rior irregularities, diastema, and overjet showed statistically signif icant improvement after treatment (p less-than-or-equal-to 0.0001). Pa tients in the permanent dentition showed statistically significant imp rovement in the crowding of lower incisors, maxillary anterior alignme nt, and overjet (p less-than-or-equal-to 0.0001). Logistic regression analysis defined five statistically significant factors (p less-than-o r-equal-to 0.05) that could differentiate patients with successful and unsuccessful treatment outcomes. These factors are low DAI scores bef ore treatment, teeth extracted during treatment, a higher pretreatment maxillary overjet, ''normal'' or close to ''normal'' pretreatment ant eroposterior molar relationship, and a short duration of treatment. Th is retrospective study concludes that: (1) treatment failures, related to changes in dental esthetics, occurred frequently for this group of patients, (2) specific pretreatment characteristics can be identified that may help determine the potential for treatment success for ortho dontic patients, and (3) further study is necessary to understand the contributions and interactions of each of these identified factors to the final treatment outcomes.