Perception gap of aged facial appearance; self-perception is younger than actual status due to angle of viewing.

Background: Facial morphology changes with aging, resulting in an aged appearance that is a great matter of concern for people. However, it is not clear whether people perceive their own facial appearance accurately, in part because there are few methods to evaluate this.

Aim: The aim of this study is firstly to establish an evaluation system for the perception gap of aged facial appearance between the self-perceived status and the actual status, and then to use this evaluation system to quantify the perception gap and to clarify the mechanism of this gap METHOD: Thirty-six middle-aged female volunteers were first asked to rate their facial aging-related morphology according to a 6-grade set of photos taken at a 45° angle from the front showing progressive stages of sagging severity, without looking either in a mirror or at photos of themselves (self- or "subjective" perception).

Subcutaneous fat infiltration into the dermal layer induces wrinkle formation.

Background: Wrinkles appear with aging, producing an aged impression, but the mechanism of wrinkle formation has not yet been fully elucidated. We recently reported that subcutaneous fat infiltrates into the dermal layer with aging and impairs skin elasticity, but the contribution of this process to wrinkle formation is still unclear.

Purpose: We aimed to clarify the contribution of dermal fat infiltration to wrinkle formation by analyzing the relationship between them in the forehead of female volunteers.

Vellus hair condition is related to dermal elasticity and facial sagging severity.

Background: Sagging of facial skin is a critical factor associated with an aged appearance. However, the mechanism of sagging has not been fully elucidated. The facial skin contains vellus hair (fine hair), but the contribution of vellus hair to skin condition and facial aging has yet to be studied.

Fat infiltration into dermal layer induces aged facial appearance by decreasing dermal elasticity.

Background: Facial morphology changes with aging, producing an aged appearance, but the mechanisms involved are not fully established. We recently showed that subcutaneous fat infiltrates into the dermal layer with aging, but it is not yet clear whether and how this drastic change of the dermal layer influences facial appearance.

Purpose: We aimed to establish the role of fat infiltration in producing an aged facial appearance and to clarify the mechanism involved.

Quantitative characterization of 3D structure of vellus hair arrector pili muscles by micro CT.

Background: Vellus hair is the fine, wispy hair found over most of the body surface, and the arrector pili muscles (hair muscle) serve to raise these hairs. Hair muscles are also critical for skin regeneration, contributing to the maintenance of stem cells in epidermis and hair follicles. However, little is known about their fundamental properties, especially their structure, because of the limitations of conventional two-dimensional histological analysis.