New finding that might explain why the skin wrinkles more on various parts of the face.
Tamatsu Y, Tsukahara K, Sugawara Y, Shimada K.
Clin Anat. 2015 Sep;28(6):745-52. doi: 10.1002/ca.22571. Epub 2015 Jul 1.
Crow’s feet wrinkles (laterally to the eyes; lateral canthus area) are typically the first to appear and wrinkles tend to be more present in some parts of the face
There are many types of wrinkles but the most common ones are due to volume loss in the dermis. This is caused by age-dependent reduction of net* hyaluronic acid / collagen production by fibroblasts
In this study from Japan (Nikko and Kyushu) 58 post mortem examinations were done on cadavers aged between 20 and 90:
-2 areas of normal facial skin were systematically analyzed (moles, wounds or scars were excluded, 52 were left):
- -forehead (approximately 10 mm above the superior margin of the right or left eyebrow
- -lateral canthal region (5 mm lateral
from the right or left lateral canthus)
Measurement of the following was done:
- -presence of wrinkles and their depth
- -sebaceous gland density
- -density of retinacula cutis (retinacula cutis are fibrous strands linking the deep dermis to the superficial fascia by drillling through the subcutaneous fat (hypodermis).
On the lateral epicanthus where Crow’s feet wrinkles are located, sebaceous glands are absent.
On the other hand, sebaceous glands are more dense on the forehead where wrinkles are less deep.
Sebaceous glands appear to play a “volume filling role” which might explain the differential distribution of wrinkles of the face.
Crow’s feet wrinkles do not have them and the first visible wrinkles often appear here
It might be useful to analyze their specific chemical properties, or if they might influence dermal cells (fibroblasts) in the production / degradation of collagen and hyaluronic acid.
*net production = production – degradation
Photo credit: wikipedia