Smile Aesthetics Assessment in Patients Undergoing the Finishing Phase of Orthodontic Treatment: An Observational Cross-Sectional Study

Objective To describe the smile characteristics of patients entering the finishing phase of orthodontic treatment. Methods This observational study involved a non-probabilistic sample of 48 patients. Clinical records served as the basis for determining the type of treatment (with or without extractions). Photographs were analyzed to obtain smile variables. Dental casts and panoramic radiographs were evaluated to ascertain the cast-radiograph evaluation (CRE) index. Univariate and bivariate analyses were conducted at a significance level of 0.05. Results The study evaluated 24 men and 24 women, with an average age of 20.10 ± 6.78 years. Fifty percent of the patients did not undergo extractions, and the average CRE index for the sample was 34.83 ± 9.01. Regarding the smile, a medium smile line was prevalent in 66.7% of cases, and a non-consonant smile arc was observed in 58.3%. Significant differences in the smile arc were found between patients with and without extractions (p=0.019). Right and left buccal corridors measured 2.52 mm ± 1.52 and 2.43 mm ± 1.37, respectively. The upper dental midline deviated by 0.80 ± 0.91 mm and had an angulation of 1.65 ± 2.05º. Both variables showed significant differences between Class I and Class II patients (p=0.020; p=0.027). Symmetrical smiles were also observed (1.05 ± 0.17). Conclusions Based on our findings, clinicians should focus on the smile arc in patients who have not undergone extractions and on the midline inclination in Class II patients. These appear to be the most common areas for improvement in patients who are in the finishing phase of treatment. Additionally, considerable variability exists in the smile characteristics of patients still undergoing orthodontic treatment, leaving room for further enhancement of results.