How Does a Physician Know Exactly What Layer S/he is Injecting a Filler Into?

There really is no substitute for injector experience and training when discussing filler treatments. It really is a "feel" that the injector has for the level of the injection. The dermis (the layer most superficial) is more firm, the subcutaneous layer, which is mostly fat, is more "loose", the injector can get an idea of the level by the resistance on the needle. When injecting in the superficial dermis, the needle is almost visible in the skin, the deeper dermis is just above where the needle resistance lessens. Experience and training are necessary to “feel” the difference.

Thank you for your very good question. This demonstrates the critical importance of choosing an experienced injector who knows exactly how deep to place an injection to achieve a safe and effective result. In most cases, the process is done by feel, and is adjusted based on the type of filler used, the treatment area, and the goal of the procedure. For example, treatment for fine lines usually involves more superficial injections, which treatments to restore volume are usually performed deeper. As long as you are working with a very experienced, board-certified injector, you can rest assured your injector will know precisely where to place the needle or cannula to ensure an optimal outcome.

A well-trained and experineced injector knows by feel which "layer" he or she is injecting to, when placing dermal fillers. Be sure you're consulting and meeting with someone reputable and experienced for best results!

     An experienced plastic surgeon, particularly one who performs many facelifts, eyelid surgeries, rhinoplasties, chin surgeries, brow lifts, fat grafting, etc., can place the filler in virtually every millimeter possible. 

It is difficult to tell the exact location of the layers but here is a general guideline.

Superficial (epidermis): you can see the needle

Mid skin depth ( dermis): you cannot see the needle and the tissue is thick and needs force to push the needle through.

Deep skin (Sub-dermis): Needle can move through easily in all directions.

To be accurate in placement takes practice and experience.

Regards

Dr J

Disclaimer: This answer is not intended to give a medical opinion and does not substitute for medical advice. The information presented in this posting is for patients’ education only. As always, I encourage you to see your personal physician for further evaluation of your individual case.

Yes, if the injector is experienced, they can feel what layer they are in.  If your injector is a board certified plastic surgeon, they know the layers very well as see them during their surgical dissections and also have studied them in anatomy.  If your injector is not a plastic surgeon or doctor or does not have a lot of experience, you need to be very careful having them inject you.

 

Good Luck

The dermis is very dense.  The cannulas are blunt and cannot effectively be manipulated to be used for dermal applications.  They are primarily used for subcutaneous filler placement.  Small needles are used for intradermal application.  While a physician should know with approximately accuracy how deep they are with filler product, in fact it is not possible to know this with certainty.  Intended intradermal treatment may end up just below the dermis.  Generally this does not seem to be much of an issue except in cases when a little too much product is placed in the dermis producing a Tyndall effect.  These are easy enough to correct when they occur.

Normally, it is possible to tell which layer an injection of Restylane, or any other filler is placed.  The depth of injection and the resistance to the needle can both be used to determine if the injection is in the dermis or below it.  The levels within the dermis itself are determined more by the depth of the needle alone.  

An experienced injector is trained in the levels of the skin and knows without thinking about it how deep to inject.  It really is second nature to someone who has been injecting for many years.  That is why it is so important to go to someone experienced.  All too often I see injections too superficial etc.  Always seek out a board certified dermatologist.

OhSoCurious,

You ask a smart question: How does the injector know how deep she is injecting dermal fillers like Restylane, Juvederm, or Perlane? The answer is that it is NOT "readily obvious" as you ask. There are accidentally decent injectors, who can do all right on the more straightforward areas (which can still lead to permanently damaging defects in the face if done wrong), and there are trained, experienced injectors who can visualize what's going on under the skin because they've SEEN IT with their own two eyes doing surgery. There is a big difference between these two groups. Go for an experienced dermatologic surgeon, plastic surgeon, ENT surgeon, or oculoplastic surgeon when picking your injector. Good luck!