Board of Director for International Society of Dermatologic & Aesthetic Surgery(ISDS) Scientific Director for Aesthetic Dermatology Academy Conference(ADAC) Scientific Board for 5 Continent Congress(5CC) Scientific Committee for IMCAS World Congress Scientific Committee for AMWC World Congress International Scientific Director for iSWAM Treasurer for MSAM Japanese Medical Board United States Educational Commission for Foreign Medical Graduates(ECFMG) Malaysian Medical Council Letter of Credentialing and Privileging(LCP)
Medical institution with Dr. Tinson Lim
When considering the performance of hyaluronic acid injections, it is very important to understand the concept of rheology .
Rheology is a branch of physics that aims to analyze and study the properties of matter under stress and pressure. In other words, it attempts to study the behavior of materials under stress and deformation.
In clinical applications, understanding the rheological properties of hyaluronic acid implants is very important as it helps the physician to select the right product for the right indication .
Rheological properties have four main parameters, "viscosity η", "normal force FN", "elasticity G' (shear stress)" and "elasticity E' (dynamic compression)" .
Elasticity G' (shear stress) is often discussed as an important parameter among the rheological properties of hyaluronic acid injections.
Shear stress is a force generated inside an object that causes it to shift. For example, when you smile, shear stress acts on the tissue. The sliding motion of one layer of overlapping skin over the other is called shear stress.
Elasticity G' (shear stress) basically describes the hardness of hyaluronic acid injections. The higher the elasticity G' (shear stress), the harder it is for the gel to deform.
According to Dr. Baste Ajab, Ph.D. in Pharmaceutical Sciences and Mechanical Engineering, one of Kaisense's developers, Kaisense didn't want its elastic G' (shear stress) to be too high . too high and the patient can feel the filler .
Kaisense is said to have found the right balance of elastic G' (shear stress), which represents hardness, while increasing the value of another very important parameter, the normal force FN .
The normal force FN is the force that the gel repels against compression . In clinical terms, it refers to the ability of the gel to lift skin tissue. High uplift (ability to lift tissue) is the most important attribute of the Kaisense series .
Of the Kaisense series, ``Volume'' and ``Extreme'' are said to have an extremely high ability to lift tissue, and are said to have excellent volume-up effects and sustainability.
Here, Dr. Tinsung Lim, a renowned Asian physician and a key opinion leader in the clinical application of filler rheology, summarizes the results of a study comparing the lifting power of Kaisense® Extreme and Juvederm Vista® Voluma XC. I'd like to introduce you to the thesis.
Source: Projection capacity assessment of hyaluronic acid fillers
Jérémie Bon Betemps1, Francesco Marchetti2, Tingsong Lim3, Basste Hadjab1, Patrick Michels4, Denis Salomon5, Samuel Gavard Molliard1
1. Research and Development Department, Kylane Laboratoires SA, Plan-les-Ouates 1228, Switzerland.
2.Surgeon Roma Plastic Surgery Center Private Practice, Roma 00199, Italy.
3.Clique Clinic Private Practice, Petaling Jaya 46300, Malaysia.
4. Dr. Patrick Michels Private Practice, Genève 1206, Switzerland.
5.Clinique Internationale de Dermatologie Genève SA Private Practice, Genève 1201, Switzerland.
Correspondence to: Dr. Samuel Gavard Molliard, Research and Development Department, Kylane Laboratoires SA, Plan-les-Ouates 1228, Switzerland. E-mail: firstname.lastname@example.org
How to cite this article: Bon Betemps J, Marchetti F, Lim T, Hadjab B, Micheels P, Salomon D, Gavard Molliard S. Projection capacity assessment of hyaluronic acid fillers. Plast Aesthet Res 2018;5:19. http:// dx.doi.org/10.20517/2347-9264.2018.24
Received: 17 Apr 2018 First Decision: 18 May 2018 Revised: 11 Jun 2018 Accepted: 11 Jun 2018 Published: 28 Jun 2018
Science Editor: Raúl González-García Copy Editor: Jun-Yao Li Production Editor: Cai-Hong Wang
Purpose: Hyaluronic acid (HA) is considered the gold standard biomaterial used for facial soft tissue correction. For the last eight years, physicians have been clamoring for high-lifting HA products that restore depleted facial volume in the cheeks, cheekbones, chin, crow's feet and jawline. Lifting capability is therefore an essential attribute for HA infusions, especially products dedicated to facial volume restoration.
METHODS: This article presents, applies and reviews a new skin model assay to evaluate the uplifting ability of HA infusions.
RESULTS: This skin model assay allows efficient assessment of the uplift ability of HA injections. A comparative evaluation of the benefits of the new OXIFREE technology and the benefits of Juvéderm Voluma reveals that the OXIFREE product has a higher lifting capacity than the Juvéderm Voluma.
CONCLUSIONS: This assay has proven to be an important tool in guiding clinicians in selecting effective tissue thickening products for optimizing facial volumizing cosmetic outcomes. was done.
Keywords: hyaluronic acid injection, lifting capacity, skin model test method, facial volume
Hyaluronic acid (HA) injections are considered the gold standard in aesthetic medicine for treating the signs of facial aging, such as injections into wrinkled, sunken skin, and facial volumization . According to the American Society for Aesthetic Plastic Surgery (ASAPS), 2.49 million cases of HA injection therapy were performed in the United States alone in 2016, showing a high growth of 16.1% compared to the previous year. 2].
Juvéderm Voluma (Allergan, France), the first HA volumizer and still the world market leader in this area, was launched in 2010.
Since then, physicians have become more and more interested in HA injections, which are highly effective in thickening skin tissue .
Juvéderm Voluma is manufactured with patented technology VYCROSS . The technology uses a combination of high and low molecular weight hyaluronan during the cross-linking process to enhance the chemical reaction.
Recently, a novel proprietary manufacturing technology was discovered for the production of innovative HA infusions. That is the OXIFREE technology (Kylane Laboratoires, Geneva, Switzerland), which is characterized by the removal of harmful oxygen during production processes such as the cross-linking step.
This largely retains the inherent property of the HA chain of high molecular weight. With this new technology, HA infusions have been created with advanced rheological properties that are capable of exhibiting a high lifting effect and therefore high resilience to facial skin tissue volume.
Volumizers, such as Juvéderm Voluma and HA injections benefiting from OXIFREE technology, are designed to be injected into subcutaneous tissue and supraperiosteal zones. Such products require high lifting capabilities to effectively treat areas of the face requiring volume, such as the cheeks, cheekbones, chin, corners of the eyes and jawline.
As the rheological properties are very important for the mechanical behavior of HA gels in tissue, these features are of course taken into account during the design [5-7].
A number of papers have been published on this topic over the last few years, some of which highlight the important role of the normal force FN on the tissue prominence of HA infusions [8-11]. In this article, we propose a new skin model assay to evaluate the lifting ability of HA injections.
The assay is applied to Juvéderm Voluma, the market leader in the volumizer space, and a new HA infusion that benefits from OXIFREE technology to compare the lifting effects of these products. The results obtained from the skin model assays are then reviewed with particular attention to the key rheological characteristics of these two products.
Two HA injections intended for facial injection in aesthetic medicine were subjected to flow test, oscillatory shear stress test and compression test using a DHR-1 rheometer (TA Instruments, Newcastle, USA). .
Of the two HA injectables shown in Table 1, one is manufactured with the new OXIFREE technology and the other is Juvéderm Voluma (Allergan, France) with VYCROSS technology.
Table 1: Description of HA volumizers benefiting from Juvéderm Voluma and OXIFREE technology
|product name||Manufacturer||Manufacturing technology||HA concentration (mg/mL)||clinical indications||comment|
|Gel D||Kylane Laboratoires (Geneva, Switzerland)||OXIFREE||twenty four||Injection into adipose tissue or intraepithelial zone, restoration of facial volume||Product with the highest lifting capacity among HA fillers to restore facial volume|
|Juvederm Voluma||Allergan (Pringy, France)||VYCROSS||20||Injection into adipose tissue or intraepithelial zone, restoration of facial volume||/|
The two HA injections were investigated in terms of their rheological properties and also using new skin model assays.
In the flow test, the viscosity η of the gel can be measured. The operating environment was a temperature of 25° C., a shear rate of 0.001-1000 s −1 , a 2 degree cone/plate aluminum geometry at 40 mm, and a 50-μm gap between the cone and plate of the rheometer. The value of viscosity η is evaluated at a shear rate of 1 s-1.
In the oscillatory shear stress test, the elastic modulus G' (G prime) can be measured. The operating environment was a temperature of 25°C, a shear stress oscillation mode with a strain of 1.0%, in the linear viscoelastic regime, a 2 degree cone/plate aluminum geometry at 40 mm, and a rheometer cone-plate gap of 50-µm.
Measurements were performed at frequencies ranging from 0.1 to 5 Hz. The values of elastic modulus G' were measured at 1 Hz, the physiological oscillation frequency.
The compression test in static mode allows measurement of the normal force FN. The operating environment was a temperature of 25 °C, a normal force mode, a cone/plate aluminum geometry of 2 degrees at 40 mm. Lower to squeeze the gel. Normal force (FN) was measured at a cone-plate gap of 1.11 mm (inverse gap = 0.9 mm-1).
Compression tests in dynamic mode allow measurement of the elastic modulus E' (E prime). The operating environment was a temperature of 25°C, a stress vibration mode with a strain of 1.0%, in the linear viscoelastic regime, a 40 mm plate/plate aluminum geometry, and a 0.5-µm gap between parallel rheometer plates. Measurements were performed at frequencies ranging from 0.1 to 5 Hz. The values of elastic modulus E' were measured at 1 Hz, the physiological vibrational frequency.
All measurements were performed in triplicate. Data are expressed as mean ± standard deviation. A coefficient of variation of less than 10% was considered good. Results were statistically evaluated by Student's t-test with the significance level fixed at α =0.05.
The skin model 'Injection trainer' (Limbs & Things, Bristol, UK) used to evaluate the uplift ability is a multi-layered structure consisting of epidermis, dermis, fat and muscle tissue. This artificial skin model may also be used for training to practice intradermal, subcutaneous and intramuscular tissue injection techniques. A layer of skin can also be ripped off.
For evaluation of the uplift ability of two HA infusions, Juvéderm Voluma and OXIFREE product (Gel D), we apply the following protocol and use an artificial skin model as follows.
- Exactly 0.80 g of each HA gel is pipetted onto the surface of the middle layer of skin after stripping off the top layer of skin.
- Overlay the top layer of skin with two HA gels.
- Take a standard image from a distance of 30 cm (front view, camera used is Nikon D5000, lens is Nikon AF-S DX VR II 18-200 mm f/3.5 - 5.6 ED).
- Measure the height of the bump produced by each HA gel administration in millimeters [the difference between the apex of the ellipse and the baseline (the baseline is the section connecting the two inflection points of the ellipse)].
One test is performed with Juvéderm Voluma on the left side and Gel D on the right side on the skin and one with Juvéderm Voluma on the right side and Gel D on the left side.
Each measurement was performed in triplicate. Data (ridge height) were expressed as mean ± standard deviation.
Statistical tests are used to compare the average of 6 bump heights of Juvéderm Voluma with the average of 6 bump heights of Gel D (OXIFREE technology).
In this two-way test (comparing two means at a given value), the mean difference (Juvéderm Voluma and Gel D) is compared to the D0 value. The D0 value is fixed as equal to zero to allow verification of the equivalence of the two means.
Important Rheological Properties Viscosity η, Static Compression FN, G Prime in Dynamic Shear Stress and E Prime in Dynamic Compression in a Novel HA Injectable (Gel D) Benefiting from Juvéderm Voluma and OXIFREE Technology was measured. Table 2 shows the results.
Table 2: Key rheological properties of the two HA volumizers
|product name||Viscosity η (Pa.s) at 1 sec-1||Compression normal force FN at 0.9mm-1 (cN)||Elastic modulus G' at shear stress at 1 Hz (Pa)||Elastic modulus E' in compression at 1 Hz (Pa)|
The elevation height measured by the skin model assay is shown in Figure 1 and the global findings are summarized in Table 3.
Figure 1: Diagram of ridge height measured in skin model assay
Step 1: Deposition of tested HA gels Step 2: HA gels are covered with a top skin layer Step 3: Measurement of the height of bumps induced by each HA gel
Table 3: Protrusion Heights of Two HA Volumizers Obtained in Skin Model Assays
|product name||Bump height (mm)|
|Gel D||2.38 ± 0.07|
|Juvederm Voluma||1.77 ± 0.08|
Statistical comparison of the mean values of each of the six bump heights for Juvéderm Voluma and Gel D (OXIFREE technology) revealed a statistical difference between the two mean values (Juvéderm Voluma and Gel D). be done.
A new OXIFREE product, Gel D, shows a 34% higher lift height than Juvéderm Voluma.
This article presents a new skin model assay, applied to two HA volume formulations, including the market-leading Juvéderm Voluma, that yields reproducible bump heights and a significant difference between the two products tested. is allowed.
Therefore, this new assay is effective and reliable for assessing the ability of HA infusions to thicken and volumize.
The raised height measured by this assay method can be considered equivalent to the ability of the tested gel to push up and thicken the skin tissue and restore the volume of the face.
Therefore, this assay is very convenient for comparing the uplifting ability of HA infusions, especially HA volumizers.
For the two HA volumizers reviewed in this article, the new OXIFREE product has significantly and statistically higher elevation height as measured by the skin model assay than Juvéderm Voluma. The lifting capacity obtained with the OXIFREE product is thus higher than with Juvéderm Voluma.
This finding is consistent and correlates with the rheological properties of the two HA volumants tested. As stated in the prior literature on the important rheological characteristics of HA injectables, the normal force of compression FN plays a key role in the uplift ability of HA injectables.
That is, the higher the FN, the higher the ability of HA products to lift skin tissue. In this regard, the normal force of compression, FN, may be referred to as the projection force to emphasize the significance of its capacity for tissue uplift and volume formation.
For the product and Juvéderm Voluma, as shown in Figure 2, the uplift force FN and uplift height of the OXIFREE product is considerably higher than that of Juvéderm Voluma. This explains the considerably higher lifting ability of the OXIFREE products observed in the skin model assay.
Therefore, the uplift capacity measurement by the skin model assay is a novel and valid tool for the medical community to evaluate and compare the uplift capacity of HA injectables, which reinforces and correlates with the rheological properties of FN. .
This measurement allows physicians to select HA volumizers with maximum lifting capacity for the treatment of facial indications that require significant volume restoration such as cheeks, cheekbones, chin, corners of the eyes and jawline. become.
This choice leads to optimized cosmetic outcomes and improved patient satisfaction.
This new skin model assay is not only capable of demonstrating the lifting ability of HA injections, but also has the simplicity and speed of visual observation of the lifting ability on models with the product applied.
Figure 2: Rheological properties and ridge height of two HA volumizers
A: Graph of uplift force of two HA gels
B: Photo of ridge height with two HA gels
C: Graph of ridge height of two HA gels
In conclusion, volumizers play an increasingly important role in minimally invasive cosmetic procedures and contribute significantly to the global growth of the HA infusion market.
HA volumizer is an important clinical indication for facial rejuvenation, such as treatment of cheeks, cheekbones, chin and chin contour, liquid gold for rejuvenating facial volume loss, especially mid-face correction. Clearly the standard.
Rheological characterization has proven to be very useful in guiding physicians in optimal product selection and use, dosing technique and depth of injection for the intended treatment.
This article proposes a new skin model assay to evaluate the lifting ability of HA injections. This skin model assay was proven to be reliable and reproducible using two HA volumizers, including market-leading Juvéderm Voluma.
This makes it easier to appreciate the ability of HA infusions to lift tissue and create volume. It is also possible to compare the level of lifting ability of different volumizing HA products.
Therefore, this model complements the rheological properties of the uplift force FN and is considered an important new tool for assessing the uplift potential of HA injectables.
Additional insights from this new skin model assay will better characterize HA infusions that may be selected and used by physicians seeking patient safety and satisfaction while optimizing cosmetic outcomes. It will be a boost for
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Biography of Mr. Baste Ajab
Ph.D. in pharmacy and mechanical engineering. Entered the HA field in 2006. Involved in research and development, engineering, and manufacturing.
・Actively participate in and develop the renewal of HA filler (Belotero®).
• Successful start-up of HA filler production plant for Belotero's FDA approval.
・In 2014, medical science education is the main activity.
As an independent expert, as International Brand Director for Merz, and as Global Head of Medical Affairs, he has given numerous lectures to aesthetic medicine organizations.
・Currently contributes to the development of HA fillers for Kylein, as well as several research and development and clinical programs
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Introducing Dr. Tinson Lim
Dr. Tingsong Lim from Malaysia, who is one of the most active young doctors in Asia and serves as a director of the International Society of Dermatology and Cosmetic Surgery (ISDS). He is actively involved in academic research and training in Asian face and body aesthetics, clinical application of rheology of fillers, facial hyperfilling syndrome, pigmentary disorders, laser treatment, and regenerative medicine. Dr. Tinsung Lim, who graduated from Tohoku University School of Medicine on a Monbukagakusho Scholarship, is fluent in four languages (English, Chinese, Bahasa Malay, and Japanese) and gives frequent lectures at home and abroad.
This seminar includes content that has not been approved by the Pharmaceutical Affairs Law.
Only medical personnel (doctors, nurses, and hospital staff) can view this page.