Relationship between the retinacula cutis and sagging facial skin

<jats:title>Abstract</jats:title><jats:sec><jats:title>Background</jats:title><jats:p>Sagging skin is one of the most concerning esthetic issues for elderly individuals. Although reduced skin elasticity has been reported as the cause of sagging skin, a loss of skin elasticity alone is insufficient to explain sagging facial skin. This study investigated the mechanisms underlying sagging skin, with a focus on the subcutaneous network of collagenous fibers known as the retinacula cutis (<jats:styled-content style="fixed-case">RC</jats:styled-content>).</jats:p></jats:sec><jats:sec><jats:title>Methods</jats:title><jats:p>To evaluate the structure of the <jats:styled-content style="fixed-case">RC</jats:styled-content> noninvasively, tomographic images of the face were obtained using magnetic resonance imaging (<jats:styled-content style="fixed-case">MRI</jats:styled-content>). The <jats:styled-content style="fixed-case">RC</jats:styled-content> was identified by comparing <jats:styled-content style="fixed-case">MRI</jats:styled-content> results with histological specimens of human skin. A descriptive scale was used to evaluate the degree of sagging, and a device equipped with a 6‐mm‐diameter probe was used to measure the elasticity of deeper skin layers and evaluate the physical properties of the skin.</jats:p></jats:sec><jats:sec><jats:title>Results</jats:title><jats:p>The density of <jats:styled-content style="fixed-case">RC</jats:styled-content> in subcutaneous tissue correlated negatively with sagging scores and positively with elasticity.</jats:p></jats:sec><jats:sec><jats:title>Conclusion</jats:title><jats:p>These results imply that a sparse <jats:styled-content style="fixed-case">RC</jats:styled-content> structure contributes to a reduction in the elasticity of subcutaneous tissue, resulting in a greater degree of sagging facial skin. These findings are expected to contribute to the understanding of the mechanisms underlying sagging skin.</jats:p></jats:sec>