Comparison of mini aesthetic parameters of smile in pre- and post-treatment periods in patients underwent orthognathic surgery

Aim: The aim of this study is to compare the mini-aesthetic parameters of smile in patients underwent orthognathic surgery at the pretreatment, preoperative and post treatment periods. Materials and Methods: This retrospective research was carried on the photographs of 50 patients who underwent orthognathic surgery and met the inclusion criteria. The "mini-aesthetic parameters of smile" were measured and compared on extraoral frontal smile photographs taken at the "beginning of treatment", "before orthognathic surgery" and "end of treatment" stages. Dolphin Imaging Version 11.8.06.22' (Dolphin Imaging and Management Solutions, Chatsworth, CA, USA) Program was used to measure the reference values in the photographs. These eight mini-aesthetic parameters of the smile were "outer commissural width", "inter labial gap", "amount of upper incisors display", "buccal corridors", "upper lip curvature", "smile arc", "amount of gingival display" and "smile index". For this study, the sample selection was not made by calculating the minimum number of individuals, and the photographs of all patients who met the criteria were included in the study. Statistical analysis of the data was carried out using the SPSS 22.0 program. Results: It was determined that the means of "outer commissural width", "inter labial gap", "amount of upper incisors display" increased in the pre-operative and end-of-treatment stages compared to the beginning of the treatment (p<0.05). Before orthodontic treatment, an inverted smile arc was observed in 43 patients, and a straight smile arc was observed in 7 patients. At the end of the treatment, the number of patients with a convex smile arc was 36 while the number of patients with a straight smile arc was 14 and any inverted smile arc was never detected. There was no significant change in the upper lip curvature among the stages. The smile index parameter was significantly higher in women than in men at the initial and preoperative stages of treatment. Conclusion: The findings indicate that in patients who underwent orthognathic surgery mini-aesthetic smile parameters show significant improvement.