Canons of ideal facial dimensions and facial beauty

Canons of ideal facial dimensions have been known since antiquity (ancient Greek and European Renaissance art) and remain relevant. Horizontal (into thirds) and vertical (into fifths) anatomical proportions can provide a valuable framework for cosmetic interventions. Symmetry is a hallmark of pretty faces. Overall, facial harmony needs to be considered for better esthetic results.

Facial esthetic procedures’ success depends not only on improving facial features but also on facial harmony. Several canons of esthetic dimensions have been described, and these concepts can provide a valuable basis for procedural planning.

Dermatologists can modify facial proportions with available cosmetic interventions. The established parameters and ratios of facial dimensions are elaborated here.

Horizontal thirds – Leonardo da Vinci described dividing the face into equal thirds in his writings on human anatomy. The upper third extends from the trichion (the midline point of the normal hairline) to the glabella (the smooth prominence between the eyebrows). The middle third extends from the glabella to the subnasale (the midline point where the nasal septum meets the upper lip). The lower third extends from the subnasale to the menton (the inferior end of the chin).

The lower face can be divided into thirds, with the upper third extends from the sub nasale to the stomion (the midline point of the oral fissure when the lips are approximated) and the lower two-thirds extends from the stomion to the menton. A 30% upper lip to 70% lower lip-chin proportion may be the most appropriate per current standards.

Vertical Fifths – in the vertical dimension, as per the neoclassical canon, the face is divided into into equal fifths. The two most lateral fifths extend from the lateral helix of each ear to the lateral canthus of each eye. The eye fissure lengths (measured between each eye’s medial canthus and lateral canthus) represent one-fifth. The middle fifth is estimated between the medial canthi of both eyes (medial canthus to medial canthus). This length is equal to the width of the nose, as measured between both alae. Finally, the width of the mouth represents 1.5 times the width of the nose. These ratios of the vertical fifths are seen in both males and females.

Lips – in the lower facial third, the lips are a crucial component of attractiveness. Recently, lip augmentation, aimed at creating full and plump lips, has dominated popular culture and social media. An upper-lip-to-lower lip ratio of 1:2 was judged to be the most attractive.

Golden ratio – about 2400 years ago, the Pythagoreans enlightened us with the golden ratio, also called the “Divine Proportion.” The golden ratio, also known as Phi, is approximately equal to 1.618. The golden ratio can be observed in nature, art, and architecture. It may be a possible marker of beauty in the human face and has sought the attention of many. The ratio of mouth width to nose width or the ratio of tooth height to tooth width are some ratios applied to several proportions and structures of the face. Trichion, menton, nasion, and subnasale are among those researchers of facial beauty consistently employ. Its utility in clinical practice is limited. At present, no evidence suggests that the golden ratio determines facial beauty.

Age-related changes – facial proportions are guided by genetic and racial factors. Several changes in facial proportions occur with increasing age due to the changing dimensions of the skin (decrease in skin elasticity and collagen produces the appearance of wrinkles and skin laxity), soft tissue (fat atrophy and hypertrophy affect soft-tissue proportions, seen as hollowing at the temples, cheeks, and around the eyes, along with fullness in the submental region and jowls), and bone (bone resorption and expansion cause a reduction in facial height as well as an increase in facial width and depth). Dermal fillers, fat grafting, liposuction, and skin tightening techniques can help to provide a youthful appearance in old age.

Genetic, cultural, and environmental factors may alter facial beauty. Faces of different cultures and ethnic groups have other characteristics too which may be found attractive. Improving facial esthetics requires to know the norms of facial proportions. Most notably, clinicians should be mindful of facial proportions and overall facial harmony in ideal vertical and horizontal divisions of the face when injecting fillers or implants at the temples, zygomatic arch, jaw, chin, and lips. Giving attention to all target areas leads to greater patient satisfaction. Current technology allows for a better assessment of facial beauty by utilizing a combination of techniques to evaluate the facial structures (bone, muscle, fat, and skin).