Relationship between the depth of facial wrinkles and the density of the retinacula cutis.

Objective To identify whether there is a relationship between the depth of facial wrinkles and the density of the retinacula cutis in the subcutaneous tissue of the skin. Design Wrinkle depth was assessed with image analysis on the forehead and the lateral canthus of human cadavers. The density of the retinacula cutis was measured in Azan-Mallory –stained skin sections obtained around the wrinkles. Setting Gross Anatomy Section, Kagoshima University Graduate School of Medical and Dental Sciences. Participants Fifty-five male and female cadavers (35-93 years old). Main Outcome Measures The maximum depth of each wrinkle was used to represent the wrinkle's degree. In the skin sections, the density of the retinacula cutis was measured around the deepest point of each wrinkle in a 1-mm-wide area (the wrinkle-specific area) and a 10-mm-wide area that included the wrinkle (the wrinkle-inclusive area). Results In both the wrinkle-specific and wrinkle-inclusive areas, the retinacula cutis densities became lower in the forehead and in the lateral canthus areas. When a wrinkle was shallow, the density was lower in the wrinkle-specific area than in the wrinkle-inclusive area. With wrinkle progression, the density difference between the wrinkle-specific and the wrinkle-inclusive areas gradually decreased until there was no apparent difference. Conclusions Facial wrinkles seem to develop above sites of reduced lower retinacula cutis density. As a wrinkle develops, the density decreases in both the wrinkle-specific and the wrinkle-inclusive areas, whereas the density difference between those areas vanishes.