Sewing needles date back some 60,000 years, but the history of needles in medicine can be traced to 1844, when the first hypodermic needle was created in Ireland. Biocompatible facial injectables, meanwhile, came to market in the 1960s and 1970s, but it took a few more decades for the technology to become what it is today. With the boom of medical aesthetics, it’s not just the tools that have seen innovation. The techniques in which they are administered has also evolved to offer a more comfortable experience that yields a subtle, natural-looking, and youthful result.
Dermal fillers address soft tissue loss, depressed scars, atrophy, or asymmetry, while neuromodulators, like Botox®, temporarily relax muscles to prevent wrinkles or reduce the appearance of them (they also have therapeutic indications to treat excessive sweating, migraines, and even jaw pain). Many consider aesthetic providers akin to sculptors, molding and shaping the face with aesthetics and anatomy in mind. The structure of facial muscles and the location of blood vessels and nerves will determine where injectables are placed, how they are administered, and what kind of needle is used.
Skilled with a syringe and instructed with a vision, their hands work to gently insert the injectable in ways that complement the facial structure. To further understand the process of injecting from a provider’s perspective, we spoke with the experts.
During the consultation process and facial assessment, “providers should discuss their method of injecting with their patient,” explains Kian Karimi, MD, a double board certified facial plastic reconstructive surgeon in Los Angeles. Those who are needle-wary can feel safe as their faces are marked for proper injection placement, as each requires the utmost precision.
So, what goes on as the needle is inserted? Here are a few of the techniques used in aesthetic medicine:
- Multiple Injection: Also known as serial puncture or ‘string of pearls,’ this technique is done through multiple injection sites to address specific areas of concern. In cases when a single droplet or a few are necessary to help create symmetry, the single-injection technique is referred to as ‘depot.’ This has become the preferred method in the last few decades for neuromodulator injections, though it may create more bruising. “With depot, you can go down to the bone or tissue and do a bolus of filler,” explains Jason Emer, MD, a board certified dermatologist in West Hollywood.
- Linear Threading: Also known as tunneling, linear threading works as the needle is inserted, withdrawing the injectable in one move. This method can be performed in two ways: retrograde and anterograde. With the retrograde technique, the injectable is withdrawn in droplet amounts as the injector removes the needle. With anterograde, the product is injected when the needle is inserted. Anterograde may be performed for tear troughs or the vermilion border because it allows the injector to better visualize the product tracking. Retrograde linear threading is used to fill in deeper wrinkles (think: the nasolabial folds and marionette lines) or to plump the lips.
- Fanning: Often done in the cheeks, this technique allows for more product to be distributed throughout the area. Referred to as fanning because the needle is only inserted once and then redirected to a different radial plane, Dr. Emer says this style decreases bruising risk due to limited injection sites.
- Cross-Hatching: Done through a row of linear threads overlapped by another row aligned at an ‘X’ angle to create a slanted grid-like pattern, this technique allows for the injector to fill more product in the desired area. The multiple linear thread injections may be performed in specific areas, such as nasolabial folds or cheeks, to evenly distribute the product, though it may lead to more bruising.
- Grid: Similar to cross-hatching, the grid technique is done through linear threads at a right angle to allow for more distribution of the injectable.
- Ferning: Similar to linear threading and fanning, ferning is performed by inserting the needle and injecting the product while retracting it in a retrograde fashion. Then, along the thread, the needle is moved out to the sides imitating a fern leaf.
So, Needle or Cannula?
Injectable technique depends on the facial landscape, patient's desires, and product used, Dr. Emer says, and there are different tools that have different benefits. Traditional needles provide more precise injection, while cannulas are favored for their decreased risk of bruising and swelling. “Ultimately, you should seek a skilled professional regardless of if they use needles or cannulas,” says Lesley Rabach, MD, a double board certified facial plastic and reconstructive surgeon at LM Medical in NYC.
Allowing for more precision but also, often, more bruising, Dr. Karimi says needles are best used for deep temples, midline of the chin, hairline, and fine line injections. “In the temple, for example, you can inject with a needle safely deep on the bone of the temporal fossa,” he explains. Needles may also provide more precision, especially in depot injections.
“The use of a cannula turns injecting into an art form – you become a sculptor,” Dr. Karimi explains. He notes that the tool itself is a longer, blunt-tipped version of a needle, which allows it to target more areas of treatment from a single insertion port. “I inform all of my patients of my use of the cannula almost exclusively and the benefits, such as minimal bruising, with them,” Dr. Rabach shares.
While she believes that cannulas are “inherently safer to be used for injectables,” they come with their own side effects. “The one downside is that it can sometimes cause more swelling temporarily that is self-limited, but patients would much prefer this than the potential of weeks of bruising,” she says.
Interchanging Techniques & Needles
With individual patient concerns come individual solutions, and, for many, their skin, gender, and age will play a role in the approach the injector takes. Providers will assess the patient and, in some cases, alter the tools, techniques, or even formulations used. “A cannula is safer in the superficial portion of the temple hollow,” Dr. Karimi explains. “I use a 25-gauge cannula and dilute the filler in a one to one dilution with 0.9 cc saline and 0.1 cc 2 percent lido.” This approach “minimizes the risk of a vascular occlusion” and helps to “avoid a puffy look in this area,” he adds.
It should also be noted that certain treatment areas will require a multimodal approach, Dr. Emer notes. “Each technique has its pros and cons,” he says. “The average injector does a mix of depot and linear threads.” Dr. Rabach agrees, explaining that, in areas such as the cheeks, singular drops or depots will be needed. In such cases, “a needle is preferred,” she says.
But, in the right cases, she maintains that “a cannula provides a nearly pain-free experience, significantly reduced chance of bruising, and precise placement of filler as opposed to a needle.” Experience, however, is key. “It is a highly technical approach that cannot be done by just anyone,” she cautions.
Like Rome, injectable skills and techniques are not built in a day. They require a medically astute injector who understands the anatomy of the face, the behavior of the injectable, and the needs of the patient. To deliver the best results in the most comfortable way, providers may use one of the various treatment methods in their arsenal. Before undergoing any aesthetic procedure, be sure to consult with a board certified doctor or surgeon who is highly trained in the procedure and methodolgy you are interested in.
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