[Anthropometric analysis of facial aging in 1200 Han adult people in Dalian].

Objective: To investigate the facial aging analysis of 1200 Han adult people in Dalian with iris diameter, so as to provide reference for facial rejuvenation in Han people.

Methods: 1200 facial digital photographs from the second-generation ID card of China were stratified randomly selected as the research sample, excluding facial deformity, tattooing eyebrow, tattooing lid margin, ptosis, lip grain and eyebrow deformity cases, as well as the cases whose join point of upper eyelid and lower eyelid not exposed at the nasal side. These photos were divided into six cohorts: female aged 18, 38, and 68 years old; and male aged 18, 38, and 68 years old, with 200 cases in each cohort. The individual iris diameter was divided into 20 equal parts in each photograph, with each part marked one unit as individual iris diameter ruler. Ten values were made from a horizontal plane between the medial canthus to ten points at one face ( the line between two medial canthus is used as the horizontal line, circumocular and facial soft tissue were measured with individual iris diameter ruler on the photographs), then the results were analyzed with Adobe Photoshop software.

Results: There are statistically significant differences in eyebrow height (36.42 ± 4.22 unit in 18 years old male group, 40.22 ± 6.90 unit in 38 years old male group, 34.83 ± 9.39 unit in 68 years old male group; 37.59 ± 6.72 unit in 18 years old female group, 41.09 ± 5.15 unit in 38 years old female group, 36.84 ± 9.45 unit in 68 years old female group), palpebral fissure height, physiognomic external canthus height, palpebral fissure width, pupil height and other items (P < 0.05).

Conclusions: (1) The brow position rises to the peak level at middle age (38 years old group), then drops down gradually with aging. (2) The physiognomic external canthus moves towards the nasal side and caudal side with aging. (3) Eyeball moves towards caudal side with aging. (4) The soft tissue around bilateral angle of mouth, nasal tip and submaxilla moves towards caudal side with aging. (5) The measurement of individual iris diameter ruler can apply to analyze the aging changes of facial soft tissue, and is more suitable for the case when facial photographs are taken at different distances.