Smile Attractiveness Perception of Three Malaysian Ethnic Groups Related to Upper Dental Midline Deviations in Three Facial Forms in Individuals of Both Genders

Aim:The upper dental midline is a critical component of smile attractiveness; however, dental practice guidelines on midline shift and its influence on smile attractiveness are inadequate.This study aimed to compare smile attractiveness perceptions related to upper midline deviations among three facial types in three ethnic groups in Malaysia.Materials and methods: Smiling images of a man and a woman with adequate smile characteristics and mesoprosopic face were selected from seven people by a panel of three orthodontists.Selected images were modified to create two different facial types (euryprosopic and leptoprosopic) and later into six upper midline deviations (0, 1, 2, 3, 4, and 5 mm).A total of 36 images were evaluated using a 100-mm visual analog scale (VAS) by a total of 150 Malaysian raters (Malay, Chinese, and Indian; 50 each) (age range: 18-50 years).The scores were compared statistically using one-way analysis of variance (ANOVA) and Tukey's honestly significant difference (HSD) and paired t-test (p < 0.05).Results: No statistically significant differences were observed in attractiveness scores for female subjects across all combinations of three facial types with five midline deviations.Smile attractiveness of the male smile with a 5-mm midline deviation in the leptoprosopic face showed a statistically significant difference (p < 0.05) among all three groups of raters.Smile attractiveness of female smiles among three major ethnic groups was found to be significantly higher in all midline deviations and all three facial types compared with male smiles.More statistically significant differences (p < 0.05) between both genders were found in normal faces compared with short and long faces.Conclusions: Smile attractiveness of females was not influenced by midline deviations and facial types.A midline deviation of 5 mm in a leptoprosopic male impacted smile attractiveness perception.Gender of the individual affects the perception of smile attractiveness related to upper midline deviation among three major Malaysian ethnic groups.Midline deviation in both genders is more noticeable in normal facial types than in short and long facial types.Clinical significance: Midline deviation of an individual with any facial form may not be noticeably perceived by the general population up to 4 mm in both genders.Hence, "no treatment" could be one of the treatment options for the patient for correction of deviated midline in smile designing and related treatments with orthodontic, prosthodontic, and restorative approaches.