Commentary on: Use of LetibotulinumtoxinA for AestheticTreatment of Asians: A Consensus

Aesthetic Surgery Journal, Volume 43, Issue 11, November 2023, Pages

NP975–NP976, https://doi.org/10.1093/asj/sjad224

Published: 01 September 2023

See the Original Article here.

It was with great interest that I read the consensus article by Liu et

al on the use of letibotulinumtoxinA for the aesthetic treatment of

Asians. When it comes to the clinical application of newly

approved toxins, these types of publications are invaluable for new

injectors of a given product. Given that botulinum toxin type A

(BoNTA) units of activity for different products are not

interchangeable, the widespread adaptation of BoNTA products for

use in off-label indications, and the fact that doses and injection

patterns used in clinical trials are almost never the same as those

used in clinical practice, early clinical experience is always

welcome. In addition, although letibotulinumtoxinA is not FDA

approved, the diversity of the patient population within the United

States also makes articles like this one a valuable resource, as

preserving patient features and expressivity while also carefully

managing dynamic lines, resting expression, facial shape, and

tissue positions and contours within the lower face should always

be a central treatment goal. As the authors note for their patients

in Asia, it is also uncommon for me to encounter a patient who is

seeking a frozen or unnatural-looking outcome. Thus, dose must

be carefully controlled using di!ering reconstitution or dilution

volumes, and product carefully placed according to each individual

patient’s anatomic patterns and muscle mass.

Although treatment must certainly be individualized, I do not

know that starting with a low dose and titrating up is the optimal

approach, as this may lead to undertreatment and loss of the

patient in some instances if results are not easily apparent to them.

Instead, I recommend estimating the optimal e!ect based on

individual anatomy and resultant pattern of dynamic lines, as well

as muscle mass. Consistent with the authors' recommendations,

however, I do encourage patient feedback, and tell patients at their

initial injection that just like getting to know the personality of

another person with time, with each session we can identify any

needed dose adjustments and compensatory muscle changes as we

get to know their facial muscles. I find that this reinforces both the

need for continuity in care and encourages the patient to carefully

observe their results over time. The authors state that

comprehensively understanding the relationship between the

muscle and overlying skin tissue is essential, and I would argue

this is indeed the case, and relevant for any toxin: the skills that

make one an excellent injector with one toxin can be applied to all

of them.

The authors note that in Asians, the nasalis is stronger than in

Caucasians. This is an important point because the nasalis is often

undertreated, irrespective of patient ethnicity. Instead, lessexperienced

injectors tend to rely only on injections placed in the procerus to reduce the appearance of “bunny lines.” I was also happy to see a discussion of BoNTA injection in the temporalis, as

this is an important part of masseter treatment, especially in

patients who experience tension or pain due to teeth grinding or

clenching. I appreciate that throughout the manuscript, the

authors made note of common compensatory activities which arise

following initial treatment. The authors are right to note the need

to avoid uneven weakening of the frontalis as well, as this can give

rise to a patchy or uneven e!ect that is just as unnatural looking as

a frozen forehead.

One point that I feel deserves some clarification is the

recommendation that the platysma be injected superficially so that

deeper muscle fibers can continue to function normally. The

platysma is an incredibly thin muscle, and BoNTA, once injected,

can diffuse not only in the x and y direction, but also in the z

direction. Thus, any injection in the platysma should be with small

volumes only, and injections should be very superficial. Because

tissue layers in this area are so thin, injections that feel as though

they are just barely subdermal are indeed within the muscle.

Personally, to minimize the risk of any complications I restrict

injections to transverse neck lines, platysmal bands (which are

grasped and pulled slightly away from the neck before injection),

and along the jawline (within 2 cm of the mandibular margin,

behind the marionette line), rather than the entire surface of the

neck as shown in Figure 3 in the original article. Even if these

injections are very superficial, they are likely to act on the muscle

fibers of the underlying muscle, and I am not convinced that a

wider field of e!ect in the platysma is of additional benefit.

Instead, I find it best in the neck to restrict injection to the area

where toxin action is desired, within the bands.

Although I appreciate that there is sometimes a need to manage

the lower aspect of the frontalis, especially in instances where

there is a desire to control brow position (for example in cases of mephisto), in

the schematics shown in the article's Figure 1, the injection points within the

low frontalis are quite close to the orbital rim, and therefore too likely to

drop the brow for my personal practice, even if the injections are superficial. Instead, I

elect to keep injections at least 1 cm above the orbital rim, but as

low as possible within this range, as it prevents di!usion into the

inferiormost fibers of the frontalis, which are very near the

muscles of the glabellar complex.

Although I did spot some di!erences in injection technique

compared to my own, I do believe that this is a very thoughtfully

written paper which takes into account the benefit of more

superficial injection for achieving a balanced aesthetic e!ect. The

authors have clearly provided a considered and complete

description of a wide range of aesthetic applications for

letibotulinumtoxinA and provide valuable information on a wide

range of injections.

Irrespective of BoNTA product used, it is imperative that the

injector understand facial anatomy, variations present (both

within and between di!erent patient populations), common

compensatory actions from other muscles which may emerge

following treatment, and the relationship between product

concentration and delivery on outcomes. Should

letibotulinumtoxinA become available in the United States, this

paper will be a valuable resource for establishing preferred dosing

across areas. Beyond delivery of the product itself, it will be

important to learn more about subtle di!erences in clinical

performance and the “personality” of the toxin when injected. As

always, it is a pleasure to learn from our colleagues in Asia, where

so much of what we know about the activity of BoNTA when

injected into the dermis or for shaping the face and body has been

pioneered. Thank you for this excellent addition to the literature.

Disclosures

Dr Lorenc is a consultant for Allergan (Irvine, CA), Galderma (Fort

Worth, TX), Merz (Raleigh, NC), Suneva Medical, Inc. (San Diego,

CA), and Thermi (Irving, TX), and received an honorarium from

Canfield Scientific (Parsippany, NJ) for scale development.

Funding

The author received no financial support for the research,

authorship, and publication of this article.

REFERENCE

1 Liu S, Cong L, Pongprutthipan M, et al. Use of letibotulinumtoxinA for

aesthetic treatment of Asians: a consensus. Aesthet Surg J.

2023;43(11):NP962-NP974. doi: 10.1093/asj/sjad151

Google Scholar WorldCat Crossref

Author notes

Dr Lorenc is a plastic surgeon, Department of Plastic Surgery, Lenox Hill

Hospital, New York, NY.

Dr Lorenc is a clinical editor for Aesthetic Surgery Journal.

© The Author(s) 2023. Published by Oxford University Press on behalf of The

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