Aim To determine the prevalence of dental development anomalies and type of influence on the smile of adolescent students. Method This was a cross-sectional and analytical study carried out in two public (A1) and two private (A2) schools chosen by lot in the city of Parnaíba-Piauí. The sample calculation was based on the target population: number of people enrolled in public and private schools between 15 and 19 years, in the city of Parnaíba-PI, which totaled 6209 students in 2020, according to a survey carried out by the Brazilian Institute of Geography and Statistics – IBGE. A questionnaire on epidemiological data and aesthetic self-perception of the smile was applied to 160 adolescents between 15 and 19 years old, from August 2020 to July 2021. The clinical examination was carried out under natural light, to check for the presence of anomaly(s) in the dental development. Students who presented only one pathology would be called group 1 (G1), those who presented two would be called group 2 (G2) and those who presented 3 or more would be called group 3 (G3). On the other hand, adolescents in whom no anomaly was evidenced would participate in the control group (CG), both in A1 and A2. Results It was observed that 37.5% of the sample had only a type of dental anomaly, corresponding to 60 individuals. The most prevalent were enamel hypoplasia, fusion, transposition, agenesis, ectopic eruption, microdent and dens-in-dent. It was possible to verify a higher prevalence in the maxilla, private schools (76.6%) and females (86.6%). In 45% of adolescents with dental anomalies, embarrassment was observed when smiling. Conclusion The prevalence was relatively high, highlighting the enamel hypoplasia, influencing the smile esthetics of a reasonable number of adolescents, whether for acquaintances, strangers or even for photographs.

Aim To evaluate the prevalence and factors associated with gummy smiles in adolescents aged between 15 and 18 years attending high school. Methods The cross-sectional and quantitative study was carried out during the Covid-19 pandemic, with 160 adolescents, from two public (A1) and two private (A2) schools chosen by lottery, divided into two groups: G1 (with gummy smile) and G2 (no gummy smile). A clinical examination was carried out on the adolescents, investigating the presence or absence of a gummy smile (GS), by analyzing the variables (interlabial distance at rest, upper incisor exposure at rest, smile arc, measurement from the subnasal to the upper lip philtrum, upper lip length, upper lip thickness, hypermobility and lower/middle third ratio). Means and dispersion were obtained, and the Chi-square association test was applied, to compare the results between A1 and A2 and between G1 and G2. Results The prevalence of GS was 33.8% (=54). It was found that no statistically significant associations were found (p > 0.05), regarding the type of school and gender with the presence of GS in adolescents. There was no statistically significant difference (χ2 = 1.82; p = 0.07) between the groups and the age of adolescents. There was a significant association between the studied variables and GS (p < 0.05). Conclusion The prevalence was high with a predominance of females. There were no statistically significant associations regarding the type of school and gender, but there was a significant association between gummy smile and lip dimensions.