# Non-Surgical Touch-Up with Hyaluronic Acid Fillers Following Facial Reconstructive Surgery
## 4 Discussion
Even if many approaches have been proposed, the treatment of choice for post-parotidectomy deficit restoration is still missing [112], and invasive surgical procedures are related with the risk of facial nerve injuries. These reconstructions include a stem-ocleidomastoid flap rotated into the defect and elevating a superficial musculoaponeurotic flap prior to performing parotidectomy. These reconstructive options help in postoperative facial symmetry improvements, reducing contour asymmetry, especially in cases of total parotidectomy [111]. Multiple microsurgical reconstructive options exist for soft tissue reconstruction. Anterioral thigh free flaps have been the \"mainstay\" of treatments due to variability in their size and shape, and the presence of large vessel calibers available for microvascular anastomosis [113]. Other options include the latissimus dorsi free flap, which is difficult to harvest, a high postoperative donor site morbidity, and a superficial inferior epigastric artery free flap, which has much smaller caliber vessels [112]. Because of the rising interest in minimally invasive techniques for aesthetic and functional head and neck surgeries, [PERSON] and [PERSON] proposed autologous fat graft reconstruction as a means of restoring post-parotidectomy facial defects [114; 115]. The usefulness of minimally invasive HA injections for the treatment of post-parotidectomy facial defects is supported by the significant, subjective improvements after treatment. The rationale underlying the potential effectiveness of HA injections is that this technique should fill the gap between the skin and the residual parotid lodge tissue, restoring the appropriate facial volume and contouring. Thus, the injections have a good aesthetic impact, as they fill the depression left by parotid gland excision, as shown by the post-operative VAS in the treated case. This technique could be performed without any anesthesia; it is well tolerated, safe, and does not lead to significant morbidity or facial nerve injury. Nevertheless, patients have to be informed that the procedure may need to be repeated to achieve a definitive result. The parotid area is injected superficially under the skin in the subcutaneous tissue overlying the parotideomasseteric fascia with microcannia. Then, the cannula is cautiously inserted underneath in a plane parallel to the skin and slowly directed inferentially in fan-like movements. The aim is to deposit the gel in the subcutaneous layer in the region delimited cephalad by the zygomatic arch and caudal by the region between the angle of the mandible and mastoid process, just above the deep cervical fascia. The end point of the treatment is the elimination of the concavity of the area injured from the previous surgery and the achievement of a uniform or even slightly convex contour among the zygomatic arch, mandibular angle, and sternocleidomastoid muscle. The superficial subcutaneous layer is mostly important in the parotid area where it contributes to the contour and the general shape of the face. An optimal deposition of the material with cannula requires two ports of entry, one in the pretragal area and the other located caudally in front of the earlobe. Working superficially with a cannula in this area prevents damage to the numerous vessels in the area and to the branches of the facial nerve located under the subcutaneous layer and superficial musculaponeurotic system (SMAS). According to our reconstructive purposes, we need only a tightening effect that is commonly achieved with cohesive gels with moderate G' and G\", used in order to have good spreading of the material throughout the compartment, with a filling effect potentially improvable with a delicate massage. Thus, a 26 mg/mL, PEGDE cross-linked, HA hydrogel (Neauvia Organic Intrase Flux, Matex Lab, Lugano, Switzerland) was used in order to spread evenly in the subcutaneous tissue and to not be \"heavy\" on the skin of the area.