A team of scientists in Japan published their study in the journal Clinical Anatomy, conducted new research on cadavers which may explain why some wrinkles are shallower in the forehead than in the outer eye area.
The team say that the presence of oil-secreting glands and a thinner inner layer of skin, or dermis, may let the skin deform more easily and might be a cause for the development of wrinkles.
“In conclusion, the findings of this study suggest that sebaceous gland density is one of the multiple factors that prevent wrinkle deepening, and that is why wrinkles are deeper in skin on the lateral canthus than on the forehead,” say the study authors, Yuichi Tamatsu, Kazue Tsukahara, Yasushi Sugawara andKazuyuki Shimada.
“These findings will contribute to the understanding of facial wrinkle development and to the development of anti-wrinkle treatments.”
In their study, the researchers used images of skin specimens from 58 male and female donated bodies ranging in age from 20 to 90-plus at the time of death.
Tissue slices were then analysed for different factors including density, elasticity and the effects of sun exposure.
The existence of moles, wounds or scars excluded the use of some of the bodies for regional observation, leaving 52 cadavers for study of the forehead region and 51 cadavers for study of the outer eye region.
The results showed that on the forehead, wrinkles were shallower in specimens with a higher sebaceous gland density, while no correlation was found around the outer eye due to the lack of sebaceous glands in that region.
The bodies that had a higher sebaceous gland density were also reported to have a thicker dermis and/or less solar damage.
From the results, the research team say that sebaceous gland density seems to be one of the factors that prevents wrinkle deepening, which explains why wrinkles are deeper around the outer eye than on the forehead.