August 15, 2022

lip filler techniquesChances are, you have heard of the 4-millimetre needle technique for lip enhancement – Teoxane heavily promote this method for use with their Teosyal RHA2 dermal filler brand, however, it works well with other low viscosity hyaluronic acid-based products.

In this blog, Dr Tim Pearce will share some expert tips on the 4mm needle technique for lip shaping and contouring of the vermillion border, and adding volume to the lip as a low trauma injection technique. He will also discuss the advantages and disadvantages of the technique.

Shh…Dr Tim will soon be revealing a very exciting new ‘ultimate’ lip course that will cover EVERYTHING you need to know about injecting the lips. Sign up >> to be the first to know when it goes live!

What is the 4mm lip injection technique?

The 4mm technique minimises the amount of trauma required to deliver a good result with lip shaping and augmentation procedures. The concept behind the technique is the use of a potential space that is almost hidden in the vermillion border to allow product to flow in a way that maintains the natural shape of the mouth. The crux of the technique, and for it to work well, is that it relies on the use of a very low viscosity hyaluronic acid-based product, examples being Teosyal RHA2, Juvéderm Volbella, or Belotero Soft. If the needle is placed correctly, you can allow product to flow in a very neat line in the vermillion border.

What are the advantages of using the 4mm lip injection technique?

Like many injection techniques, there are advantages and disadvantages to the use of the 4mm technique. These should be weighed up against the risks, desires, benefits, and expectation of your patients.

Advantages to the 4mm techniques include a significant decrease in the amount of trauma caused to the patient’s lips, for two reasons. One, because you are only placing 2-3 mm of the needle into the lip to place your injection. Alternative approaches would include placing the entire length of a longer needle into the lip which would cause more trauma. And two, the ability of low viscosity products to flow along the vermillion border decreases the amount of trauma and injection points required to deliver the product – we simply harness this natural ability to flow, instead of having to be ‘placed’ with a needle, to achieve a low trauma result.

Another advantage comes if you choose to aspirate as you inject; it is much more sensitive using a short (4mm) needle with a low viscosity product, which will increase your safety.

There may also be an aesthetic advantage because as you are tracking the natural shape of the vermillion border you get a more natural result. It is therefore also likely to be less painful for your patient than other techniques since you are following the natural structure of the tissues and using a very short needle.

What are the disadvantages of using the 4mm lip injection technique?

As the product flows centrally along the vermillion border, a small amount of volume is added to the pink lip and a small amount to the white lip. This has the downside of slightly enhancing the white part of the lip, which may be a disadvantage in some cases and an alternative approach to lip shaping may be more suited to some patients.

Sometimes, the labial artery may be closer to the surface than we would expect, some evidence suggests that it lies 6mm beneath the skin, whereas other cadaveric studies have demonstrated a depth of only 3mm. Thus, as injectors, we cannot simply rely on the use of a short needle to decrease the risk and increase our safety, we must inject in a way that minimises the depth of injection – thus Dr Tim notes that the technique is better used as a 1-2mm depth, rather than a full 4mm needle technique.

As the injection technique is very superficial, aspirating can sometimes pull the needle out of the vermillion border causing you to lose your needle placement. It may be safe not to aspirate with such a superficial approach, as the superior and inferior labial arteries are usually relatively deep underneath the orbicularis oris muscle. As you are injecting, you should easily see where the product is flowing along the vermillion border. If this were to change and you could not see it moving, then you should stop injecting immediately.

How to perform the 4mm lip injection technique

4mm lip filler techniqueThe classic 4mm technique relies on placement of the needle right in the vermillion border within this ‘channel’ which is only a potential channel at this stage.

You should place it in such a way that if product travels upwards, away from the injection point, you are going to enhance the vermillion border. This takes practice and you will need to try it many times before finding a smooth flow when treating most patients. The average distance that the dermal filler will flow before it stops and you need to reinsert your needle higher up the vermillion border varies from case to case, sometimes it will be 2mm or 3mm, and sometimes it can be up to 10mm or more. With an average set of lips, you can expect two to three injection points on either side of the lip with product flow of approximately 1cm per section. As you inject there will be a little bit of higher pressure product deposition from one end to the other, so you will need to employ gentle massage to even out the linear thread of product.

Now we have enhanced the vermillion border, the next stage is volumisation, still using the 4mm needle to place dermal filler within the middle quadrant of the lip. Here, you place 0.1ml per section, but this is variable dependent on the result you are aiming to achieve; you can place more or less filler as required. Most of the volume is placed medially, in the middle three fifths of the lip. To enhance the Glogau-Klein point (the two apex points of the Cupid’s bow at the end of each philtral column), use a small injection at each apex and place 0.05ml-0.1ml for projection.

With the 4mm lip technique, some of the injections are designed to create definition and some to produce volume, but this approach can be varied to fit each patient and should not be relied upon as a cookie-cutter solution for all patients, you should adapt to suit.

4mm lip fillers technique


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Lip Filler Treatment & Complications

With all the conflicting advice out there about lip filler treatments – vertical or horizontal? needle or cannula? – it can be difficult to know how to inject to create the lips your patient desires.

If you are suffering from technique overwhelm, worrying about causing a vascular occlusion (VO), or panicking about injecting thin lips, then Dr Tim Pearce’s brand-new ultimate lip course is going to teach you the different techniques, anatomy, and skills you need to create medically beautiful lips.



Dr Tim Pearce eLearning

Dr Tim Pearce MBChB BSc (Hons) MRCGP founded his eLearning concept in 2016 in order to provide readily accessible BOTOX® and dermal filler online courses for fellow Medical Aesthetics practitioners. His objective was to raise standards within the industry – a principle which remains just as relevant today.

Our exclusive video-led courses are designed to build confidence, knowledge and technique at every stage, working from foundation level to advanced treatments and management of complications.

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