Improvement in smile esthetics following orthodontic treatment: A retrospective study utilizing standardized smile analysis

Abstract

To quantify smile esthetics following orthodontic treatment and determine whether these changes are correlated to the severity of the initial malocclusion. A standardized smile mesh analysis that evaluated nine lip-tooth characteristics was applied to two groups of successfully treated patients: group 1 (initial American Board of Orthodontics Discrepancy Index [DI] score<20) and group 2 (initial DI score>20). T-tests were used to detect significant differences between the low-DI and high-DI groups for baseline pretreatment measurements, baseline posttreatment measurements, and changes from pre- to posttreatment. A Spearman correlation test compared the initial DI values with the changes in the nine smile measurements. Five of the smile measurements were improved in both groups following orthodontic treatment. Both groups demonstrated improved incisor exposure, an improved gingival smile line, an increase in smile width, a decreased buccal corridor space, and an improvement in smile consonance. Spearman correlation tests showed that initial DI value was not correlated to changes in any of the individual smile measurements. Smile esthetics is improved by orthodontic treatment regardless of the initial severity of the malocclusion. In other words, patients with more complex orthodontic issues and their counterparts with minor malocclusions benefitted equally from treatment in terms of their smile esthetics.