tissue fibers influences the position and the tension of the overlying skin.
Agents classified as biostimulators are injected into the subcutaneous tissue to induce neocollagenesis.7,9,26 It can be assumed that placing the product deep to the superficial fascial system may result in a limited skin tightening effect as the short connective tissue fibers or the superficial fascia are not precisely targeted. On the contrary, it can also be assumed that biostimulator agents have their greatest effect on the skin surface if they are positioned inside the superficial fascial system ie, between the skin and the superficial fascia where they can directly affect the subdermal short connective tissue fibers improving skin firmness and the support of subcutaneous structures. Of note, this subdermally located layer of fat has been shown to vary in thickness with age, body mass index (BMI), and gender.15,16,18 This can create challenges in correct product placement and can thus influence the aesthetic outcome of the procedure.
The goal of this ultrasound-based study is to measure the thickness of the superficial fatty layer in a large sample with a balanced distribution of gender, BMI, and age. The measurements will be used to develop mathematical formulas whereby the thickness of the superficial fatty layer can be estimated based on the information of gender, BMI, and the age of the patient. This could potentially guide practitioners to more effective outcomes with biostimulator products as the superficial fatty layer including the short connective tissue fibers can be precisely targeted.
Agents classified as biostimulators are injected into the subcutaneous tissue to induce neocollagenesis.7,9,26 It can be assumed that placing the product deep to the superficial fascial system may result in a limited skin tightening effect as the short connective tissue fibers or the superficial fascia are not precisely targeted. On the contrary, it can also be assumed that biostimulator agents have their greatest effect on the skin surface if they are positioned inside the superficial fascial system ie, between the skin and the superficial fascia where they can directly affect the subdermal short connective tissue fibers improving skin firmness and the support of subcutaneous structures. Of note, this subdermally located layer of fat has been shown to vary in thickness with age, body mass index (BMI), and gender.15,16,18 This can create challenges in correct product placement and can thus influence the aesthetic outcome of the procedure.
The goal of this ultrasound-based study is to measure the thickness of the superficial fatty layer in a large sample with a balanced distribution of gender, BMI, and age. The measurements will be used to develop mathematical formulas whereby the thickness of the superficial fatty layer can be estimated based on the information of gender, BMI, and the age of the patient. This could potentially guide practitioners to more effective outcomes with biostimulator products as the superficial fatty layer including the short connective tissue fibers can be precisely targeted.
MATERIALS AND METHODS
Study Sample
150 Caucasian individuals (75 males, 75 females) with a mean age of 44.03 ± 14.08 years [range, 20–68 years] and a mean BMI of 26.93 ± 4.49 kg/m2 [range, 19.57–39.18] and Fitzpatrick skin types I–III were investigated applying ultrasound imaging (Table 1). The study was conducted between January and December 2017 at the Vida Skin Surgery and Laser Centre, Clinica Vida, Sao Paulo, Brazil.
The total sample consisted of 15 males and 15 females from each of the following decades: 20–29 years, 30–39 years, 40–49 years, 50–59 years, and 60–69 years. Of the 30 individuals investigated (15 males and 15 females) per decade, 10 individuals (5 males and 5 females) had a BMI ≤24.9 kg/m2, 10 individuals (5 males and 5 females) had a BMI between 25.0, and 29.9 kg/m2, and 10 individuals (5 males and 5 females) had a BMI ≥30 kg/m2 (Table 1).
Written information and verbal explanations about the aims and the scopes of the study as well as about the risks of the procedure (ultrasound imaging) were provided to the participants before the inclusion into this study. Following the Declaration of Helsinki protocols (1996), written informed consent to participate in this study was obtained from all participants. This study was conducted in accordance with regional laws and good clinical practice.27
Ultrasound Imaging
Ultrasound imaging was performed using a linear 15 MHz transducer (MTurbo portable, Fujifilm SonoSite, Inc., Bothell). Patients were standing upright during the scanning process to account for the effects of gravity. Measurements were performed without application of pressure to the skin as the transducer was placed into the visualization gel only without direct skin contact (Aquasonic® Clear Ultrasound Gel, Parker Laboratories Inc., Fairfield, NJ). Measurements were performed bilaterally in the following locations (Figures 1-3):
150 Caucasian individuals (75 males, 75 females) with a mean age of 44.03 ± 14.08 years [range, 20–68 years] and a mean BMI of 26.93 ± 4.49 kg/m2 [range, 19.57–39.18] and Fitzpatrick skin types I–III were investigated applying ultrasound imaging (Table 1). The study was conducted between January and December 2017 at the Vida Skin Surgery and Laser Centre, Clinica Vida, Sao Paulo, Brazil.
The total sample consisted of 15 males and 15 females from each of the following decades: 20–29 years, 30–39 years, 40–49 years, 50–59 years, and 60–69 years. Of the 30 individuals investigated (15 males and 15 females) per decade, 10 individuals (5 males and 5 females) had a BMI ≤24.9 kg/m2, 10 individuals (5 males and 5 females) had a BMI between 25.0, and 29.9 kg/m2, and 10 individuals (5 males and 5 females) had a BMI ≥30 kg/m2 (Table 1).
Written information and verbal explanations about the aims and the scopes of the study as well as about the risks of the procedure (ultrasound imaging) were provided to the participants before the inclusion into this study. Following the Declaration of Helsinki protocols (1996), written informed consent to participate in this study was obtained from all participants. This study was conducted in accordance with regional laws and good clinical practice.27
Ultrasound Imaging
Ultrasound imaging was performed using a linear 15 MHz transducer (MTurbo portable, Fujifilm SonoSite, Inc., Bothell). Patients were standing upright during the scanning process to account for the effects of gravity. Measurements were performed without application of pressure to the skin as the transducer was placed into the visualization gel only without direct skin contact (Aquasonic® Clear Ultrasound Gel, Parker Laboratories Inc., Fairfield, NJ). Measurements were performed bilaterally in the following locations (Figures 1-3):
