Prevalence information on excessive gingival display in post-orthodontic patients is limited. By studying one aspect, namely the size relationship of the clinical crowns of teeth, in an orthodontic population, we can begin to quantify their need for periodontal plastic surgery. In this two part study, 200 plaster models were used as subjects, followed by a clinical exam of 31 of those subjects. These models represented patients before and directly after orthodontic therapy, and the Part 2 clinical exams were performed at least five years later. The lengths and widths of the six anterior teeth were measured and these values were compared to known ideals. This study revealed a significant increase in the length of the maxillary anterior teeth over the three examinations, yet these values were still approximately 1.5mm shorter than ideal. The mean tooth width-to-length ratio was 87-88% for maxillary central incisors, clearly below the accepted "ideal." As well, 61-71% of maxillary central incisors exceeded allowable tooth width-to-length ratios, and 61% of subjects displayed asymmetry in gingival architecture. Although this study only examined one aspect of excessive gingival display, it is the first study to show that in a predominantly young, post-orthodontic population, the prevalence of non-ideal width-to-length ratios is greater than 65%, and that the presence of asymmetry is greater than 60%. Therefore, close interaction between the periodontist and the orthodontist is necessary to diagnose these conditions in order to provide patients with all options for improving their smile.

BACKGROUND: Smile esthetics play a major role in the perception of a person’s attractiveness, as well as other social parameters. The study aim was to see if altering the gingival display of patients would affect perceptions of the aforementioned social parameters. METHODS: Smiling photographs were taken and then digitally altered so as to lengthen the teeth and reduce the amount of gingiva. These photographs were shown to a group of senior dental students, and a group of evaluators with no formal dental training. Groups were asked to rate each picture’s attractiveness, friendliness, trustworthiness, intelligence, and self-confidence. RESULTS: The digitally altered photographs were rated higher for all five social parameters than were their unaltered counterparts (p<0.0001). There were no statistically significant differences between the two groups of evaluators. CONCLUSIONS: Excessive gingival display positively affected how attractive a person’s smile is judged, and also how friendly, trustworthy, intelligent, and self-confident they are.