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PROMOTION


HYALURONIC ACID DERMAL FILLERS


Dr Uberto Giovannini explains why hyaluronic acid dermal fillers are so important for aesthetic treatments


DR UBERTO GIOVANNINI, CPRE Millenaire Montpellier


T


HE CONCEPT OF SOFT tissue augmentation is continuously attracting individuals who are ageing but are eager to look better.


implants date back to 1889 with the introduction of paraffin


The first injectable heterologous in humans.


Owing to the side-effects produced, use of paraffin had to be abandoned. The use of liquid silicone was evaluated from 1961 in the medical field and was successively extended to the area of aesthetic procedures. Since 1970, new technologies have introduced the


immunogenic


potential of bovine collagen, used for the correction of wrinkles and scars. In 1985, different types of collagen were introduced to the market, followed by other substances, such as hyaluronic acid (HA), known generically as dermal fillers. Hyaluronic acid was first described in 1934 as a crystal modifier. In the foetal wound healing process, the prolonged presence of the hyaluronic acid is provided as long as the matrix orchestrates signal healing by regeneration. Hyaluronic acid and the HA-


stimulating activity decrease during the transition period from foetal-like to


adult healing. The skin constitutes the primary reservoir of HA in the body—more than 50% of the total reserve—and it has a half-life of 24– 48hours. The total quantity of HA found in a 70kg person is approximately 15g. Its average turnover rate is 5g/d. Hyaluronic acid is actually used


across a wide variety of medical fields, while a HA-rich matrix is permissive for cell motility proliferation. In cosmetic practice, HA is the


injectable dermal filler of choice for most surgeons. However, long lasting alternative substances such as calcium hydroxylapatite and poly-L-lactic acid have appeared with improving results in recent years. However, they often cause reactive fibrosis of tissues and are only indicated for filling into deep tissues.


A cosmetic surgery revolution The dermal fillers have brought in a virtual revolution in the field of cosmetic surgery in recent years. The hyaluronic acid provides a safe and effective method for neutralising the effects of ageing and stress and regain a youthful and healthy appearance, without coming under the sharp knives of surgeons and


with minimal down time. The dermal fillers vary widely in their physical and chemical characteristics and many variables contribute to their overall performance. The degree of crosslinking, gel hardness, gel consistency, viscosity, extrusion force, HA concentration, and extent of hydration are a cornerstone in the outcome of the cosmetic procedure. For stabilising the cosmetic


hyaluronic acid it is necessary to reticulate it. The most common product used for linking is 1,4-Butanediol diglycidyl ether (BDDE). The problem of BDDE is the mutagenic potential and the residual product after HA degradation. The adverse effect of BDDE are erythema, oedema and ecchymoses.


In long


lasting complications we can describe granulomas, infection, and extrusion. BDDE is the cross-linker used in the majority of the market-leading HA fillers. After reaction with HA, the epoxide groups of BDDE are degraded but unreacted BDDE remain. The quantity and the toxicity are undergoing studies, but increasing awareness associated with the procedures popularity brings us to suggest that BDDE free production is a safer alternative.


Figure 1


Augmentation of the lips with Medifeel


90 ❚


28mg. (A) before, (B) during, and (C) after procedure


March 2015 | prime-journal.com


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