Under the Microneedling Scope
Dr Abs Settipalli asks if RF Microneedling is really worth all the hype
RF microneedling has become an increasingly popular procedure. But with so many devices on the market, practitioners need to have a factual understanding of electricity and physics to see for themselves which devices are a waste of time and money and which are truly fantastic treatments. Crucially, this can be done without any marketing, opinions or subjectivity.
What is Fractional RF needling (FRFN)?
‘Fractional’ refers to a fraction of a portion of skin being treated at a time. Specifically, it is a regular pattern of needle point-sized dots that correlate to the needles in the handpiece. ‘RF’ refers to the form of energy being sent into the target tissue. ‘Needling’ refers to the fact that this energy in the form of radiofrequency is being delivered from the end of needle tips.
All energy devices take energy in one form and convert it into another to deliver it to the skin. This delivery then causes either damage (e.g. coagulation) or non-damage (e.g. enzyme activation) changes in the skin. In all cases, the initial energy form is electricity. Our devices then use internal circuitry to convert this into something else. That ‘something else’ is then what interacts with our skin. In the case of FRFN, the electricity goes from needle to needle once it’s inside the skin. Very importantly, this means that the skin becomes part of the electrical circuit. As a result of this energy (being too much for it to handle), it coagulates. This coagulation zone is then taken away by the body, and new tissue is created to take its place. This is where we see visual changes - once this has taken place. The new tissue should be much more youthful than that which it replaced.
Herein lies the crux of where all clinicians have no idea why their device is terrible or fantastic. It is for this reason that readers should check their devices against these facts. This is something many manufacturers fail to make clear in their marketing.
What determines coagulation and, therefore, quality of the result?
To understand this answer, one must remember that the skin is essentially the same as a wire; it is in a circuit that electricity is flowing through. Therefore, the laws of electricity apply whether the clinician thinks their device is the best already or not. Pay close attention…
Electricity, when it travels through a medium, encounters resistance. Theoretically, there may be instances where this isn’t the case, e.g., using a superconductor. This is beyond the scope of this article, however.
Think of the resistance as a protesting crowd trying to go down a particular road. The police have now arrived and are trying to ‘resist’ the crowd. They form a line with riot shields to push back - to ‘resist’ their advance. This resistance has reduced the amount of crowd travelling down the road. Some of the officers are injured, and the crowd starts to push through much easier - the resistance has reduced, and the crowd can flow much more now.
Resistance in a circuit is the ability to ‘resist’ the attempt of charge carriers to circumnavigate the circuit and deposit the energy they are carrying to specific outputs, e.g., a bulb in the case of a ceiling light’s circuit. The resistance is affected by factors such as temperature and the atomic makeup of the medium the electricity is trying to travel through. For example, when a semiconductor such as silicon gets hotter, it has less resistance; when it’s very cold, your car has trouble starting up.
This means that when there is more resistance in the ceiling light’s circuit, but the amount of energy going into the circuit is the same, the light is dimmer. With higher resistance, we have to increase the energy going into the circuit so the bulb is still the same brightness as before. Reread this paragraph if needed. It underpins every case you will ever treat with FRFN.
Now let’s imagine the bulb can be picked up and carried around with you. Whenever you visit anywhere, you have to plug your bulb in. But, wherever you plug it in, you can increase or decrease the voltage going into it so that if you plug it in at the pub where there’s more resistance, you can still have the same brightness by increasing the voltage. After the pub, you decide to go to the gym. At the gym, they have almost no resistance whatsoever. So, when you plug your bulb in here, it’s far too bright; you have to reduce the voltage you select to keep the bulb at the same brightness… The output of your bulb’s brightness can only ever be the same if you manipulate the voltage going into it by taking into account how much resistance there is in the circuit that it’s plugged into.
Your skin is the bulb. The coagulation is the brightness. To guarantee that you get the same brightness/coagulation every time, you must measure the resistance across that skin before sending voltage through the circuit. Otherwise, when you plug your bulb in at the pub and don’t increase the voltage to account for the high resistance, you may as well be using a glow worm in a jam jar. Otherwise, when you insert the needles into patient ABC with higher resistance in that part of the face, your coagulation zone will be smaller. Then, there will be less remodelling. Then, there will be less new and youthful tissue. Then you will have less of a clinical result. If you don’t have a device capable of doing this and claim to get good results still, think how much better your results and reputation would be if you had a device that did.
Remember this article when a sales rep attempts to tell you that you don’t need to measure resistance to get the same coagulation zone every time.
Clinically, how do we replicate optimal coagulation every time?
Unfortunately, there are not many devices in the world currently that can measure the resistance of the skin between the needles and instantly change the voltage of the circuit before delivering power for a split second. Some may give a resistance reading but offer nothing beyond that. At the time of writing this article, the Genius by Lutronic may be the only one in the world capable of this. Before continuing, Consulting Room and the author here have no connection to Lutronic or conflict of interest. Mentioning the Lutronic Genius is a matter of objective and bias-free education only.
The Genius has a unique system whereby needles penetrate a specified depth and pause for a split second before energy is delivered. This measurement of resistance is shown on the screen, and a feedback light on the handpiece glows either green or red to signify whether the same amount of energy has been delivered.
What other factors affect coagulation?
Many factors exist, and to go through every single one would require literary real estate far beyond the scope of this article, unfortunately. However, touching upon a few should help the reader ask the correct questions to manufacturers to buy the most clinically effective device.
The ability to reach the desired depth is important. If 2mm is chosen as the desired treatment depth, but the needles only make it 1.75mm, clearly, there will be sub-par results. This may happen due to factors such as:
- Friction between the needles and the layers they travel through.
- Movement of the skin away from the handpiece when needle pressure is applied.
- Increased number of needles requiring more pressure to push them all through.
The friction between two surfaces is measured with the mathematical constant ‘μ’, pronounced ‘mew’. The higher the μ, the more force is needed to create movement. For example, a 25kg ice block resting on ice will be easier to slide in comparison to a 25kg rubber block resting on a rubber floor. The former has a much lower μ than the latter.
The movement of the skin deep into itself can occasionally occur because after the needles make contact, instead of piercing, they push the skin deep. This happens to us all when we inject a blunt needle instead of a sharp one. Sharpness is key to preventing this, and we tend to find this phenomenon occurring more towards the end of the appointment than the beginning for reasons which should now be obvious. Another reason is the number of needles…
The number of needles increasing means it’s harder for the same force to ensure penetration just as easily. For example, many people choose to lie in a bed of nails for whatever personal reason(s). These needles don’t penetrate their skin because there are so many - the pressure on their body is spread out over a larger surface area. But, if they lied down with a single nail, I’m sure we can all imagine this coming close to killing them. This is because their body’s pressure is now falling on such a tiny surface area. Hence, when people insist on handpieces/needle cartridges with an ever-increasing number of needles for quicker treatments, they don’t always see improved results - it’s harder for them to reach the same depth as easily.
- What should I ask a manufacturer to ensure I buy a clinically effective device?
- Can the device measure resistance before energy delivery and change voltage to account for this?
- What’s the durability of needle sharpness?
- How do you ensure the correct depth has been reached?
- What is the μ between your needles and skin?
- How many needles are in each cartridge available?
- How much are these cartridges?
- What’s the max depth these needles can reach?
FRFN can be a life-changing treatment and is a very unique modality. The biological remodelling it induces can be very effective in creating a tightening effect for our patients, amongst other things. However, the laws of physics, which Maxwell, Tesla, Faraday and Einstein owe gratitude for, still apply. To not account for their discoveries when designing an effective device is to mock at their altar. If any of them were alive today, I suspect they would be severely disappointed with the current range of devices we are pedalling.
Regardless of how good a company’s subjective marketing is, it will never outweigh the non-subjective factual laws of these great scientists. A manufacturer disagreeing with these laws is a manufacturer disagreeing with Einstein.