In facial aesthetics, the Golden Ratio has been used to derive the “Rule of Thirds”, which states that a well-proportioned face can be divided into equal thirds by drawing horizontal lines across the hairline, glabella, subnasale, and menton. Additionally, there are myriad of other formulations governing ideal facial aesthetics unrelated to the Golden Ratio, such as the “Rule of Fifths”, in which the ideal face is divided transversally into five eye-widths. These fundamental concepts of facial harmony transcend cultural and ethnic norms of beauty and demonstrate universal appeal.
The pathogenesis of facial aging includes aesthetic and anatomic alterations in all layers. Skin, muscle, bone, fat and ligaments all are affected, and both bony, gravitational and volumetric changes work in concert on the aging face. Additionally, hormonal changes often underlie these physical changes.
Understanding the pathogenesis of facial aging is critical for selecting the appropriate treatment modality.