Smile-related oral characteristics in vietnamese students

Aim: We evaluated various oral features related to the smile among Vietnamese students. Additionally, we identified gender differences in the oral features and the prevalence of attractive smiles. Materials and Method: We recruited 490 Vietnamese students with 18-29 years old and recorded their dynamic smiles. We determined the prevalence of the qualitative smile morphological features and the mean and standard deviation of the quantitative features, namely the buccal corridor space, the smile index, and dynamic smile symmetry. Results: There were diverse smile-related oral characteristics among the participants. The most common anterior smile line was “average” (42.6%), and “parallel” was the most prevalent smile arc (43.1%). We observed a “downward” upper lip curvature in 55.9% of the participants, and the “second premolar” was the most frequently displayed posterior tooth (58.6%). Most of the participants (79.2%) showed no contact between the upper teeth and the lower lip while smiling. The mean buccal corridor space was 0.59 ± 0.47 cm, the smile index was 5.85 ± 1.48, and dynamic smile symmetry was 1.01 ± 0.06. There were significant gender differences for several smile- related characteristics. Conclusions: Women more often display a favorable smile arc and more teeth when smiling, while men are more likely to have an attractive anterior smile line and upper lip curvature. These insights are vital to tailor effective aesthetic treatments.