# Non-Surgical Touch-Up with Hyaluronic Acid Fillers Following Facial Reconstructive Surgery
## 4 Discussion
Even if HA facial fillers usually last about 6-8 months, the achievement of this long-lasting effect could be explained because of deep, periperiosteal HA injections. As demonstrated by [PERSON] et al., this technique provokes an injury and a persisting inflammatory change around the injected HA that activated periosteal stem cells and induced tissue neogenesis, such as fibrosis and ossification [101]. Since separate layers of superficial and deep tissues are injected, we adopted a multi-layer technique for the use of fillers based on surgical anatomy that allows good efficacy, limited use of materials, and optimal longevity. In case of facial trauma approach, we used Juvederm Voluma with Lidocaine (Allergan, Irvine, CA, USA) and Juvederm Vollift with Lidocaine (Allergan, Irvine, CA, USA). These fillers--characterized by a mix high and low molecular weight HA chains (Vycross technology) to improve moldability, ease of modeling/shaping, ease of flow during injection, reduce swelling--improve distribution and integration within the tissue, and increase duration of effect [105]. All of these features make these fillers attractive candidates for our reconstructive goals. In our experience, the concept of facial reconstruction with HA gels is based on surgical logics; thus, the use of the most appropriate product allows the surgeon to achieve optimal results with the minimal amount of product. In fact, we have achieved an excellent reconstruction of an entire malar area with only 1 mL deep to the bone and 1 mL in the superficial layer. Our approach defines a novel reconstructive paradigm shift: in the past, fillers were used for surface treatments and short-lived results, while in our approach, fillers are used mostly to restore both facial symmetry and proportions. In fact, the levels of their injections are the deep planes, and not only the skin; the preoperative planning of injection is based on surgical concepts where maintenance of outcomes is paramount. Our volume restoration technique helps to limit the amount of filler used, improving the impact of facial sagging and depressions and contextually achieving a lifting effect in malar prominence reestablishment. It is remarkable that, in this case, the superficial nasolabial compartment is not affected by volume loss, but tends to move medically due to the lack of lateral support caused by the injury in the lateral malar area and the lack of zygoma fixation points. By this injective approach, vertical pillars are created over the bone in order to restore bone support of the malar area [Figure 1]. The lateral to medial sequence of injection helps in achieving a tenting effect, so that less material is needed in the more medial compartment, avoiding an excessive midface projection and respecting symmetry with the contralateral area. Augmentation of the deep medial cheek increases the anterior projection, not completely addressed by lateral redraping, reduces the nasolabial compartment ptosis, and recreates cheek eurhythmy within its natural boundaries and symmetry. The areas of injection are selected precisely according to the reconstructive aim of restoring anatomy. The strategy is based first on deep injections to the periosteal layer, and later on superficial injections in the superficial subcutaneous fat in a multi-plane technique. A total of 0.2/0.4 mL of gel is released in each deep injection in three separate deposits. The gel is released in small bolus and not in a continuous fashion in order to prevent a sausage effect of too much filling. No more than 0.4 mL is released per bolus to avoid the risk of compression over the lymphatic vessels. Once the deep areas are injected, we move to perform the superficial plane treatment. The treatment of the superficial layer is directed only to the area affected by the traumatic injury. In this case, a microcannula is used in order to prevent bleeding and as a tool to partially undermine the ligamentous areas of the facial retaining ligaments.