In the literature there is significant confusion between the terms hypodermis and subcutaneous adipose tissue, which are often used interchangeably. They are however two distinct and independent structures, with independent metabolic responses. The distinction between these two layers and the knowledge of their behavior is of crucial importance for choosing the appropriate treatment. The objective of the present study was to review the existing literature on the topic, in order to demonstrate the anatomical and histological differences between the two tissues.

Keywords: SUBCUTANEOUS FAT; ADIPOSE TISSUE; SUBCUTANEOUS TISSUE.

Cellulite or gynoid lipodystrophy in its various degrees is extremely common in the female population, setting on between the ages of 15 and 45 years of age, which corresponds to a woman's reproductive phase. Around 95% of women will present some degree of cellulite at some point in their lives. Despite being highly prevalent, only a few studies have been published in the international literature - many with contradictory conclusions - making it difficult to choose the appropriate treatment regimen.
The present study discusses anatomical differences in the hypodermis of men and women, the complex physiopathology of gynoid lipodystrophy, and mechanisms involved in its development.
Gynoid lipodystrophy is a skin disorder, which can only be controlled and not fully cured due to the fact that it is not a true disease, but rather a predisposition. Nevertheless, persistent or more advanced cases should be considered pathological, and be treated and controlled, given that they are indicative of peripheral vascular insufficiency.

Keywords: ADIPOCYTES; LYMPHATIC SYSTEM; LIPODYSTROPHY

INTRODUCTION: During aging, the skin undergoes structural, cellular, and molecular changes that alter its mechanical properties as well as its biological and physiological functions.These changes manifest as loss of elasticity, and turgor, with consequent appearance of fine wrinkles, lines, and creases that are difficult to resolve, being considered a therapeutic challenge.
OBJECTIVE: To describe the technique of applying cohesive polydensified matrix hyaluronic acid for the treatment of superficial wrinkles.
MATERIALS AND METHODS: In this retrospective and observational study, the technique of superficial and transverse application to superficial wrinkles with cohesive polydensified matrix hyaluronic acid was performed in women with this type of wrinkles in the perioral, periorbicular and lateral regions of the face, which did not disappear after treatment with botulinum toxin, facial volumization with fillers and technology.The study was conducted over 22 months between 2016 and 2018.The degree of improvement was assessed by a questionnaire applied to the patients who observed paired standardized photographs taken in the previous period and one month after the treatment.
RESULTS: The technique was performed on 40 women aged 55 to 80 years, whose response to the evaluation questionnaire was improved between 90% and 100% after one month of treatment.
CONCLUSIONS: The technique of superficial and transverse application to wrinkles with cohesive polydensified matrix hyaluronic acid proved to be an excellent option for the treatment of affected areas, without significant adverse events and/or Tyndall effect, with a high degree of patient satisfaction.

Keywords: Hyaluronic acid; Skin aging; Skin care