The development of microplastic surgery is based on the interaction between material science and plastic surgery concepts, and new tissue fillers have been introduced, from the first generation of hyaluronic acid to the second generation of collagen stimulators; The "ascending" of the concept is from simply filling the low-lying to the overall evaluation of the contour boundary. In the recent study, I took out a little "dry goods" to share, this is a clinical observation in 2023, through more than 200 cases of scientific observation and data analysis pairsFour-zone injection of the outer contour of the faceCarry out**. The Posterior Facial Frame (PFF) is one of the most important aesthetic units of the face, defined as the contour line from the hairline and zygomatic arch to the transverse process of the mandible and the glenoid region. In Asian populations, PFF typically presents with congenital temple depression, prominent lateral orbital border and zygomatic arch, and dysplastic mandible contours that convey messages of aging and depression. Injectable soft tissue fillers are a promising method of PFF** that has two main aspectsOne is to make PFF natural and smooth, and the other is to relieve buccal laxity. Previous injection** strategies have focused on a single site (e.g., nasolabial folds and temples), and this literature explores a solution that combines face lift and volume increase in multiple areas of the face to answer poor PFF. Based on different facial features prior to injection, 200 patients were evaluated and classified into four types (types I-IV). Type I presents with markedly sunken temples and a pronounced lateral orbital border with mid-facial posis. Type II is characterized by sunken cheeks and sagging in the front of the cheeks. Type III has the characteristics of both Type I and Type II. Type IV presents with mandibular angle dysplasia and accumulation of perioral tissues on the basis of the above three types. 
The entire injection process is as follows:1.Routine injection points are designed according to the patient's facial presentation. 2.HA is injected periosteum at the temples (A1 4 and B1 6) using a 27g 13 mm needle (BD) with a conventional injection of 03 ml HA. A total of 3 mL of HA was injected on both sides of the face. 3.Subcutaneous cheek lift technique: Using a 23g 70 mm blunt-tipped cannula, HA is injected into the superficial subcutaneous fat layer (C1 zone) and evenly distributed on each side of the face with a blunt-tipped needle5 ml of HA. 4.HA was injected supraperiosteal (D1 zone 3) and subcutaneously (d4 zone) using a 23g 70 mm blung-tipped cannula and a 27g 13 mm needle (BD) with co-injection on both sides of the face**15 ml ha。
Improving the facial contour with injections is a safe and effective way to avoid post-operative complications caused by surgery. In the 200 patients using the four-zone technique**, there were no acute vascular events, and the common uncomfortable symptoms were postoperative temple swelling and pain, which resolved within 2 weeks without any**. Although the anatomical areas involved in this technique are relatively safe, care needs to be taken to avoid injury to the superficial temporal and facial arteries. Four-zone injections are a concept that does not limit the type of filler, and there are currently a variety of injectable fillers to choose from: calcium hydroxyapatite, various HA products, polycaprolactone (PCL-"maiden needle") and some other materials with good biocompatibility and rich mechanical properties for intradermal, subcutaneous and supraperiosteal injections. In injections of the outer contours** of the face, the more supportive HA is preferred, while the low molecular weight HA used for superficial modification may cause displacement. The filler used in this literature is: hyalumatrix at a concentration of 16 mg ml, g'The value is 150Pa, the dynamic viscosity is 200000MPas, and the cohesion is 012 g/10 mm'/min。The four-zone injection method provides a combination of facial contour curves and face lifts**, and the face lift results can be attributed to the support of true ligaments and SMAS, unlike the classic MD Code strategy. However, a more rigorous study of facial anatomy is needed to explain the face lift effects of injections. Long-term clinical follow-up is necessary to fully understand the duration of the face lift and the reproducibility of the procedure. References: Chen X, Xu Y, Xiao Z, Liu G, Li M area four technique: an effective injection approach to the posterior facial frame aesthetic treatment with injectable hyaluronic acid fillers. j cosmet dermatol. 2023;22:2440-2447. doi:10.1111/jocd.15736