Background Quantification of the effect of orthodontic treatment on the gingival mircroaesthetics is lacking. The aim of this exploratory investigation was to investigate the effect of fixed orthodontic appliance therapy on gingival aesthetics associated with the anterior maxillary dentition. Materials and methods A bespoke gingival aesthetic criterion was used to assess 150 sets of pre- and post-treatment intra-oral photographs from a consecutively treated patient sample who had completed fixed appliance therapy. Five assessors rated the images assigning a score per criterion. Reliability of the method was assessed with concordance correlation coefficient (CCC) and Bland–Altman limits of agreement (LOA). Differences by timepoint, assessors, and treatment characteristics were assessed with statistical tests or generalized linear models at α = 5%. Results In the sample of 150 cases, the most common pre-treatment incisor classification was Class III (n = 57) followed by Class II Div 1 (n = 52). The majority of cases were treated on a nonextraction basis (n = 95) and involved orthodontic appliances only (n = 134). The CCC and LOA values for the aesthetic gingival criterion ranged from good-excellent. Average aesthetic summary scores differed from before pre-treatment median = 33.9; interquartile range (IQR) = 24.5–45.2 and post-treatment (median = 75.8; IQR = 65.2–85.3) to a significant degree (mean difference = 38.5; standard deviation = 17.8; P < 0.001). No difference in aesthetic criterion points score was evident for treatment plan (nonextraction vs extraction) (P = 1.00) and treatment type (orthodontic only or orthognathic) (P = 0.52). Considerable variation in summary scores among assessors with different specialty/grades was seen (P < 0.001). Limitations Gingival aesthetic ratings were undertaken in isolation without the assessment of specific contributions made by soft and hard tissues, and changes in tooth position. Conclusions Orthodontic treatment with fixed appliances can have a positive effect on the gingival margin, gingival zenith, gingival embrasure, connector area, and overall rating of gingival symmetry of the anterior maxillary teeth. However, aesthetic ratings depend on the assessor.
Seehra et al. (Thu,) studied this question.