New Interview of Dr. Babak Azizzadeh with Medscape.com on Fillers

Medscape: To set the stage, could you give a brief overview of the different filler types and their modes of action?

Babak Azizzadeh, MD: First, I think for the general medical population, it’s important to differentiate the injectables. We have neuromodulators, which are the botulinum toxins , such as onabotulinumtoxinA (Botox® Cosmetic; Allergan Inc; Irvine, California) and abobotulinumtoxinA ( Dysport™; Medicis Pharmaceutical Corporation; Scottsdale, Arizona). Then we have the filler group, and under the filler group we have what I would call nonstimulatory and stimulatory fillers. The nonstimulatory fillers are the traditional collagen and hyaluronic acid (HA) fillers. Then we have the biostimulatory fillers, such as poly-L-lactic acid (PLLA; Sculptra® Cosmetic; sanofi-aventis; Bridgewater, New Jersey) and calcium hydroxylapatite (CaHA; Radiesse®; BioForm Medical; San Mateo, California). Then there is a third category, the permanent fillers, such as polymethylmethacrylate (PMMA; Artefill®; Suneva Medical Inc; San Diego, California) and silicone.

Medscape: Could you talk a bit about the significant differences in mode of action within those categories?

Dr. Azizzadeh: The nonstimulatory fillers, such as the HAs, basically fill hollows, lines, and folds by replacing lost tissue without any other form of stimulation to the area. The stimulatory fillers, such as PLLA, actually stimulate collagen production rather than replacing tissue. CaHA is what I would call a hybrid filler: it does form replacement tissue like a HA, but it also has some stimulatory effect.

Medscape: Are there fundamental differences in injection technique among the different fillers?

Dr. Azizzadeh: Absolutely. First of all, there has been a huge transformation over the last 5-7 years in the way that all fillers are injected. Originally, most people had experience with collagen, and collagen is an intradermal and/or subdermal product. It works very well for lines, but as we’ve learned in the past decade, lines are not the most important factor in facial rejuvenation. Our advanced understanding of the role of lipoatrophy in the the aging process has given us a whole new world of facial rejuvenation. As a result, cutting-edge facial rejuvenation requires facial reshaping by replacing volume rather than filling lines.

We are, therefore, putting fillers in very different locations. For example, the HAs, such as Restylane® (Medicis Pharmaceutical Corporation) and Juvedérm® (Allergan, Inc) can not only be injected in the subdermal layer, but also deeper tissue as well such as the subcutaneous or perimuscular area, or even near the periosteum. Obviously, the deeper you inject an HA, the more product you’re going to need to use.

CaHA typically will require a deeper plane of injection than you would with a HA. You could inject at the junction of the dermis and subcutaneous tissue and be very safe and effective, and you could go deeper — near the periosteum, deep to the muscles, above the muscles. You do not want to inject CaHA near the lips or the tear trough. Your margin of error is a lot less and you end up getting nodules and so forth when you do that. That’s the key with CaHA.

With PLLA, you want to stay in the deep subcutaneous tissue. By injecting deeply, you avoid any major adverse events because the product stimulates collagen very well in those areas and gives you the outcome that you need. PLLA is not a product to fill in lines, it’s really to fill and replace lost volume in the mid face, prejowl region, preparotid region, pyriform aperture, and the temporal region. PLLA is the most powerful “volumizer” of all the injectables with great duration of 2-4 years in my experience.

For the permanent fillers such as silicone and PMMA, you want to be in the subcutaneous region and be extremely cautious. Silicone requires a microdroplet technique, where you inject a minute amount of product, wait for the results, and re-inject after the results have presented themselves. Silicone really doesn’t work as a filler; it’s much, much more of a stimulator. Permanent fillers are much more technique-dependent than other fillers. I always recommend extensive training of permanent fillers under the guidance of experienced injectors.

Medscape: You mentioned the changing paradigm of the aging face, and treating volume loss rather than chasing after lines and wrinkles. Do you find that your patients understand this new paradigm or do you need to educate them?

Dr. Azizzadeh: The paradigm shift is significant, and I think that patients understand it more and more. Still, the majority of patients come in asking for line-filling. Those patients, if you just fill in the lines, will be happy but not ecstatic. They are likely not going to come back or spread a positive word of mouth. During the consultation, we always talk about the paradigm shift, about volume changes, and I point out the areas, such as the mid face, prejowl area, pyriform aperature, and temporal region, that would benefit from volume restoration and rejuvenation. Once they see the results, they really get it, and they are the most satisfied of all patients.

Patient outcomes can also be rewarding for one’s practice. Most “filler” patients understand that the physician’s injection skills are tantamount to good outcome. They are more likely to return to the physician if satisfied with their results. On the other hand, neurotoxin patients tend to doctor shop much more often even if they have gotten great results in the past.

Medscape: How does longevity of effect vary among the products?

Dr. Azizzadeh: The different products have different longevities. In my experience, the HAs, depending on the location, will last anywhere from 4 to 12 months. In the lip area, they typically last from 4 to 6 months. In the cheek, mid face and nasolabial folds, Has can last between 6 and 10 months. In the tear trough, they last more than 12 months on average.

The longevity of CaHA varies depending on whether you mix it with lidocaine. If you don’t mix it with lidocaine, I think the longevity is between 10 and 14 months. If you do mix it with lidocaine, I think the longevity is shorter — anywhere from 8 to 12 months.

For PLLA, the longevity is much longer. In my experience, after the completion of treatments, it’s probably in the 2-4 year range. In most of the clinical trials, it was demonstrated that at 2 years, patients still had significant correction. In my experience, that probably carries out to about 3 years

Obviously with PMMA and silicone, the results are more permanent. Again, my thought process is that the aging process continues, and we have changes and shifts of the face. That’s why I really prefer the use of PLLA and shorter-lasting fillers rather than permanent fillers.

Medscape: With PLLA, how many treatment sessions are typically needed to achieve the desired correction and how do you space those treatments?

Dr. Azizzadeh: Typically it depends on the location, amount of volume loss and degree of aging changes that we’re treating. It’s anywhere between 2 and 5 treatment sessions typically, the average being probably 4 treatment sessions. The midface and lower face will typically require 3-5 treatment sessions, while temple rejuvenation will take 2-3 sessions.

I generally wait about 6 weeks between treatment sessions. Typically, most people wait about 4 weeks, but I like to extend that to about 6 weeks and I like to use an 8-cc dilution. With this protocol, I’ve been able to get excellent outcomes using less product. I used to use 2 vials per treatment session for each patient; now I use on average 1 vial per patient.

The mechanism of action is such that the stimulatory effect takes awhile, and I think 4 weeks may be too short a period of time for that effect to be realized. However, over a 6-week period you get a more reliable outcome and you can then assess and reinject depending on which areas still need improvement. Adverse events are exceedingly low for my patients who have been on this protocol.

Medscape: Are there facial areas where you prefer to use certain injectables? Are there are areas that you avoid certain injectables?

Dr. Azzizadeh: I avoid the lips and lower lids when using PLLA and CaHA. For the temple area, I love PLLA. Temple atrophy is currently underestimated, and treatment results are great. I also like PLLA for volume loss in the mid face and the prejowl sulcus. CaHA and HAs are my other choices that I use for those areas. HAs work very well for the tear trough and the lips.

Medscape: Are there different types of patients for whom specific fillers are best?

Dr. Azizzadeh: If someone has a wedding to go to in the very near future, you’re going to use a short-acting product such as an HA or CaHA. For individuals with moderate to severe aging changes who don’t want to keep coming back for injection after injection and want a long duration of effect, they’re going to do best with PLLA. For younger patients who are getting lip augmentation, obviously they’re going to do better with a HA.

I don’t really look at the patients’ age, I look at his or her goals, and I go through all the options and the different products. I don’t particularly like the permanent fillers, such as silicone and PMMA, because I think these products present a unique set of issues that patients typically are not comfortable with. Again, there are some patients who want that, and if they do, I refer them to physicians who treat with permanent products. In my hands, I really love PLLA, CaHA, and the HAs.

Medscape: Is there anything you would like to add?

Dr. Azizzadeh: We have to listen to our patients and we have to educate our patients so that we can explain the procedures and products that will give them the best results. Balance is very important. I think that we usually under treat patients, and as a result they’re not happy with the results. It’s always important to make sure that we achieve the correction that will give the patient a great result.

On the other hand, we should also recognize that the face should not be overfilled or overstuffed; there should still be contours and shadows that preserve a natural-looking face. We sometimes see people whose buccal spaces have been overfilled, so they get an unattractive round face when they started out with an oval face. Make sure that the zygomatic arch, lips and cheeks aren’t overfilled.

The injection techniques and the injection protocol are very important so that too much — or too little — product isn’t injected. Balance is very important.

Medscape: Thank you so much for being generous with your time and your expertise.

Dr. Azizzadeh: My pleasure.