Revisiting Smile Esthetics: Role of Facial Type and Buccal Corridor Area in Perceived Attractiveness

Abstract

Introduction: Smile esthetics plays a pivotal role in orthodontic treatment planning, with the buccal corridor being a key determinant of smile harmony. This study aimed to evaluate esthetic perceptions of the buccal corridor area ratio (BCAR) across different facial types among orthodontists, orthodontic patients, and laypersons and to determine the influence of BCAR variations on smile attractiveness.

Methodology: This “cross-sectional analytical study utilizing a digital stimulus perception design” included 279 participants, equally divided into orthodontists, orthodontic patients, and laypersons. Standardized frontal smiling images were digitally modified to represent three facial types (mesofacial, brachyfacial, dolichofacial) and five BCAR levels (1%, 5%, 10%, 15%, 20%). Perception scores were recorded using VAS scale. Data were analyzed using SPSS version 26. Mean perception scores were compared using ANOVA with post-stratification to control for effect modifiers such as age and gender. A p-value ? 0.05 was considered statistically significant.

Results: A significant association was found between facial type, BCAR levels, and perception scores. At lower BCARs (1% and 5%), dolichofacial faces received higher scores from patients, while brachyfacial faces were rated more favorably by laypersons and orthodontists. Orthodontists preferred mesofacial types overall, but rated brachyfacial smiles more positively as BCAR increased. Laypersons were more sensitive to BCAR changes in female models than male models. Patients consistently rated dolichofacial types with larger BCARs more favorably. Stratification by age showed higher perception scores in participants over 40 years across most groups.

Conclusions: Orthodontists are more sensitive to variations in buccal corridor size compared to patients and laypersons. BCARs below 15% are generally perceived as esthetically acceptable by all groups. Elimination or reduction of buccal corridors should be considered when BCAR exceeds this threshold, supporting the integration of patient esthetic expectations into clinical decision-making.