Calculating the Thickness of the Superficial Fatty Layer of the Body Using Age, Gender, and Body Mass Index

January 2020 | Volume 19 | Issue 1 | Original Article | 36 | Copyright © January 2020

Published online December 19, 2019

Sebastian Cotofana MD PhD,a,b Doris Hexsel MD,c Luiz E.T. Avelar MD,d Christine G. Munia MD,e Mariana Muniz MD,f Gabriela Casabona MD,g Thilo L. Schenck MD PhD,h Jeremy B. Green MD,i Nirusha Lachman PhD,j Konstantin Frank MDh

aDivision of Anatomy, Department of Medical Education, Albany Medical College, Albany, NY bDivision of Plastic Surgery, Department of Surgery, Albany Medical Center, Albany, NY cBrazilian Centre for Studies in Dermatology, Porto Alegre, Brazil dPrivate Practice, Belo Horizonte, Brazil ePrivate Practice, Sao Paolo, Brazil fPrivate Practice, Sao Paolo, Brazil gOcean Clinic, Marbella, Spain hDepartment for Hand, Plastic and Aesthetic Surgery, Ludwig – Ludwig Maximilians University of Munich, Germany iSkin Associates of South Florida, Coral Gables, FL jMayo Clinic College of Medicine and Science, Mayo Clinic, Rochester, MN

Abstract

BACKGROUND: Injections of biostimulator agents are increasing in popularity as an alternative to surgical or energy-based skin tightening procedures. The present study was designed to develop a formula that helps to guide health care providers injecting biostimulators into the correct plane to enhance effectiveness and longevity by targeting precisely the superficial fascial system.

METHODS: 150 Caucasian individuals (75 males and 75 females) were investigated with a balanced distribution of age (n=30 per decade: 20–29, 30–39, 40–49, 50–59, and 60–69 years) and body mass index (n=50 per group: BMI≤24.9kg/m2, BMI between 25.0 and 29.9kg/m2 BMI≥30kg/m2). The distance between skin surface and the superficial fascia was measured via ultrasound in the buccal region, premasseteric region, the lateral neck, posterior arm, abdomen, buttocks, anterior thigh, medial thigh, and posterior thigh.

RESULTS: Mean thickness of the superficial fatty layer is variable between the different locations investigated with smallest values for the lateral neck of 3.71mm ± 0.55 [range, 2.00–5.00mm] and greatest values for the gluteal region with 20.52mm±10.07 [range, 6.10–38.40mm]. A formula was developed to estimate the thickness of the superficial fatty layer based on the targeted region, age, gender, and body mass index of the patient: Thickness of superficial fatty layer (mm): Region constant + (XX* BMI) - (YY*Age).

CONCLUSIONS: Injections of biostimulators deeper than the calculated values might result in reduced efficacy as the superficial fascial system is not targeted and the effected collagen neogenesis does not affect the skin surface.

J Drugs Dermatol. 2020;19(1):36-44. doi:10.36849/JDD.2020.4619

INTRODUCTION

Non-surgical, minimally invasive skin tightening procedures have been shown to provide improve-ments for patients seeking skin-lifting and/or skin-tightening to overcome the signs of aging.1-10 The annually statistics report by the American Society of Plastic Surgeons, revealed that a total of 500,428 procedures were performed utilizing biostimulators in 2017.11 In 2018, this number increased by 0.5% to 502,687 procedures performed in the US alone.

The subdermal architecture is arranged in layers with the following sequence from superficial to deep: skin, superficial fat, superficial fascia, deep fat, and deep fascia.12,13 This layered arrangement can be found throughout the entire body.14-18 Of those described layers, the skin, the superficial fatty layer which includes short connective tissue fibers that connect the skin to the superficial fascia and the superficial fascia itself are considered to be a functional biomechanical unit, which has been previously termed the superficial fascial system.17,19-24 The superficial fascial system has been shown to provide major structural support for the skin and the subcutaneous fat as inclusion of this system into suturing techniques increases wound strength resulting in a better aesthetic and functional outcome after surgical procedures.25

The superficial fatty layer and the short connective tissue fibers within it have been previously identified to play a key role in the formation of surface irregularities observed in cellulite.14 This indicates that the subdermal attachment of the short connective