Background: Perception of beauty is influenced by the individual's geographic, ethnic, cultural, and demographic background. However, objective measurements remain the foundation for aesthetic evaluations. In the quest for to better define "ideal" lip characteristics, this study assumes interdependence between variables such as country of residence, sex, age, occupation, and aesthetic perception.

Objectives: This study will increase surgeons' awareness with respect to different lip size preferences. The provided information might enhance and clarify communication among plastic surgeons and aid to put often quoted "ideal proportions" in context.

Methods: An online survey was designed. Modifiable ranges of lip fullness were achieved via digital alteration, enabling participants to interactively change the shape of a single model's lips. The questionnaire was sent to more than 9000 plastic surgeons and laypeople worldwide. Demographic data were collected and analysis of variance was used to elucidate lip shape preferences.

Results: A total of 1011 responses (14% response rate) from 35 different countries were gathered. Significant differences regarding lip fullness were identified. Surgeons who practice in Asia or non-Caucasian surgeons prefer larger lips, while those in Europe and Caucasians prefer smaller lips. Lastly, laypersons living in Asia prefer the smallest lips.

Conclusions: Country of residence, ethnic background, and profession significantly impact individual lip shape preferences. These findings have implications for patients and surgeons, because differences in aesthetics' preferences can lead to dissatisfaction of patients and surgeons alike. In our increasingly global environment, cultural differences and international variability must be considered when defining new aesthetic techniques, treating patients, and reporting outcomes.