What are dermal fillers?
Dermal fillers are an increasingly popular type of cosmetic products that can be used to correct a number of aesthetic imperfections. Dermal filler injection is suitable for the treatment of lines and wrinkles between the eyebrows, around the mouth, and in the chin area, and it can also correct hollow temples, loss of volume in the cheek, and under eye bags. Injections can also augment the nose and lips and define the jaw.
Many patients are turning to dermal filler injections as an alternative to surgical procedures due to the lower risk associated with injections. Dermal filler injections also require less downtime, and though they are a temporary procedure, they offer results that can last from months to years. The longevity of the treatment depends on the area of treatment as well as the material used in the dermal filler product. The most popular material used in dermal fillers is the natural ingredient hyaluronic acid. There are also synthetic dermal fillers made of poly-L-lactic acid and calcium hydroxylapatite.
While there are a number of benefits for patients when they undergo treatment with a dermal filler, there are many dangers if a filler is injected improperly. This is why it is imperative that medical practitioners are aware of the danger zones of dermal filler injection sites.
Dangers of Injecting a Dermal Filler
When performed correctly, injecting a dermal filler is a safe, non-invasive medical procedure with few side effects. However, if the injector is inexperienced or unfamiliar with facial anatomy, there are serious dangers that can cause long-term harm.
The dangers of dermal filler injection include bruising, edema, skin discoloration, infection, nodular masses, paraesthesia, and vascular compromises that could lead to skin necrosis or blindness. Fortunately, these dangers can be avoided by observing safety measures that include keeping injections away from the biggest danger zones for dermal filler injections. Additionally, dermal filler injections should only be performed by a medical practitioner who has received the proper training.
Danger Zones of Dermal Filler Injection Sites
While it is extremely important that medical practitioners understand where and how to inject a dermal filler in order to achieve a patient’s desired result, it is just as important that injectors know which facial regions to avoid. By avoiding the danger zones of dermal filler injection sites, practitioners can prevent dangerous complications that could cause irreparable harm to the patient.
There are multiple arteries in the cheek area that are subject to the dangers of dermal filler injection. When injecting a dermal filler, medical practitioners must avoid the facial artery, the transverse facial artery, the buccal branch of the maxillary artery, the zygomatic branch of the lacrimal artery, and the infra-orbital artery. When injecting a dermal filler deep into the mid-face, it is vital to avoid intravascular cannulation or vascular injury. For safest results, use lateral injections instead of deep, direct injections. When it comes to approaching the medial cants, medial injections should be avoided all together.
The glabella region is a high-risk area due to the vessels. Vessels are small and are not a great source of collateral circulation. Additionally, injectors must avoid the supratroclear artery and the supraorbital artery. When implanting dermal fillers in the glabella region, it is recommended to use a Low-G filler and a serial puncture technique when injecting into offending rhytides. To occlude the supraorbital and supratroclear vessels along the rim, apply digital pressure to the brow area. This helps avoid complications by preventing back flow if accidental injection of vasculature occurs.
The nose area has a number of danger zones, depending on the procedure being performed. Non-surgical rhinoplasty requires caution in the nasolabial angle, columella, tip/supratip area, cartilaginous and bony dorsum, and alar lobule skin. The nasal ala—which contains the dorsal nasal artery, angular artery, and lateral nasal artery—also poses a risk. This area is so dangerous because these arteries provide blood to the medial check, nasal ala and sidewall, and the dorsum of the nose. Improper injection near the alar grove or direct injection into the vessel can cause necrosis in the nasal ala, nasal tip, nasolabial fold, and upper lip. Additionally, injection into the dorsal nasal artery can cause blindness. For safest results, injections need to be deep on the cartilage or bone and close to the midline when injecting on the cartilaginous dorsum and bony dorsum.
Peri-oral Region and Nasolabial Grooves
The region around the mouth leading up to the nose is another danger zone. In this region, there is the superior labial artery and the inferior labial artery, both of which must be avoided during injection. The facial artery is also near the nasolabial grooves. When injecting in this area, a cannula needle should be considered. If injecting into the deep dermis or superficial subcutaneous tissue in the inferior two-thirds, an anterograde and retrograde thread technique is advised.
The temples are home to the superficial temporal artery and the partial branch of the superficial temporal artery and the frontal branch of the same. For safe results when injecting a dermal filler in the temples, mix the filler in a 1:1 ratio with 0.5 percent lidocaine and epinephrine. When injecting, start at the pretrichial line and proceed laterally to medially in the superficial subcutaneous plane. Injections should be just below the dermis.
Tips for Dermal Filler Injections in Danger Zones
If vascular occlusion should occur, practitioners should respond promptly so as to prevent potential scarring and subsequent necrosis or vision loss. If the patient suffers sudden pain and/or blanching upon injection, vascular occlusion, ischemia, and impending necrosis are possible. Painless, patchy erythema, and/or expanding violaceous reticulated patch are also warning signs of complications. To prevent these harmful complications from occurring, observe the following practical techniques:
- aspirate prior to injecting
- inject the dermal filler in a retrograde fashion
- inject the filler slowly and in small quantities—0.3ml/min is a good rate
- avoid using anesthesia near vascular bundles
- avoid using epinephrine so that blanching can be spotted quickly
- use a small gauge needle to slow the flow of a dermal filler
- pinch the skin to create more space between the superficial branches of main arteries and to move the skin away from underlying vasculature
- use a product that is reversible, such as hyaluronic acid
- occlude the origin of important vessels by pressing manually with the nondominant finger
- inject in a medial and superficial plane
- observe the area of injection, making sure to check for blanching
- communicate with the patient throughout the procedure and assess pain during the injection process.
Injecting a dermal filler is a safe, effective method of correcting facial imperfections so long as the medical practitioner is knowledgeable in facial anatomy and trained in injection procedures. To ensure safe results and to diminish the dangers of injection, medical practitioners must familiarize themselves with the danger zones of injection sites and observe safe, practical techniques for preventing complications.