Botulinum toxin A is highly valued in aesthetic dermatology for the correction of mimic wrinkles. The upper third of the face is a classic indication for Botox treatments. However, other facial areas and rarer indications such as the ‘gummy smile’ are also among proven applications.
In the course of the natural aging process, the skin loses its natural elasticity, the eyes become deeper, the facial features sag, the lips become narrower and the face becomes square. However, the most noticeable symptom of aging skin on the face is the formation of wrinkles. You look older than you are, or have an annoyed, tired or sad expression on your face. “We can try to address that through aesthetic treatment,” said Prof. Claudia Borelli, MD, senior physician and head of the Aesthetic Dermatology and Laser Unit at the University Dermatology Clinic in Tübingen, Germany [1]. Here, it is important to first clarify the patient’s wishes and expectations. Achieving realistic expectations can increase compliance and satisfaction. Prof. Borelli emphasizes that it is often possible to achieve a good effect with relatively little effort. This is an important factor, he said, especially for cost-conscious patients.
Botox treatment as a basic anti-aging therapy
The use of the active ingredient botulinum has become an established standard procedure in aesthetic medicine. Botulinum toxin A injections, better known as Botox A, can be used to address and prevent expression lines that result in an unfavorable facial expression. Botox A injections also have some effect on wrinkles, as extensions of the muscles go all the way into the skin. “The skin texture also gets a little better,” she said. Which preparation is used is not so relevant, as the differences are minimal. It is more important not to aim for major changes, but to treat gently and regularly in order to harmonize the facial features. “We should keep in mind the interaction of the muscles, it must be harmonious,” explains Prof. Borelli [1]. For example, horizontal forehead wrinkles, vertical glabellar wrinkles (‘frown lines’), periorbital wrinkles (‘crow’s feet’), wrinkles descending from the lip commissures (‘marionette lines’), chin wrinkles, or wrinkles of the platysma muscle in the anterior neck region are of particular aesthetic importance [2].
Several equivalent preparations – observe dose equivalences
Today, we know a lot about how botulinum toxin works and we know its chemical structure. The first effect occurs as early as 12-48 hours after treatment with Botox A, the maximum effect is usually expected after 3-10 days, and the duration of effect is 3-5 months [3]. Botulinum toxin A is a protein consisting of a heavy chain and a light chain linked by a disulfide bridge. The active neurotoxin prevents the binding and release of acetylcholine from vesicles in presynaptic nerve terminals by cleaving the protein SNAP-25 (synaptosomal-associated protein 25 kDa). This results in blocking neuromuscular stimulus transmission at the motor endplate and inhibiting muscle contractions [3,4].
2021 A Cochrane Review was published on the efficacy and safety of botulinum toxin in facial treatments [5]. The authors included 65 randomized-controlled trials* with a total of 14,919 study participants comparing Botox A with placebo, other types of Botox, or fillers in the treatment of facial wrinkles in adults. The duration of the study was between one week and one year. One conclusion of this secondary analysis was that the differences between different Botox A preparations were minimal, explained Prof. Borelli [1,5]. “We have many good, effective preparations,” she said, adding, “Just look at what is special about each preparation” [1]. It is important, for example, to observe the dose equivalences of the respective preparations, i.e. whether one injects in Botox units or whether one has to multiply by 2.5.
* Minimum number of 50 subjects per study.
Horizontal forehead wrinkles are a common indication: what helps against eyelid ptosis?
Overall, treatment of the forehead (Tab. 1) must be highly individualized after thorough examination, since the area treated and the muscle strength as well as the brow position and mobility vary greatly. Regarding injection technique, the guideline recommends distribution with a few points in a safe region 1.5-2 cm above the brows (convergence line) intramuscularly or subcutaneously/intradermally as a wheal. The recommended guideline for the mean total dose is 4-16 U or 10-40 Speywood E in women and 10-20 U or 25-50 Speywood E in men. To avoid brow ptosis, consider possibly more dilute solution as so-called Microbotox intradermally. If possible, injections near the levator palpebrae superioris should be avoided. The corrugator muscle originates medially at the bony rim of the orbit. It has no connections to the bone in the lateral part, as it penetrates the skin. Injections performed in contact with the bone in the lateral part cause migration of the product into the levator palpaebrae muscle. If the levator palpaebrae muscle is paralyzed by the neurotoxin, ptosis of the eyelids may result. To treat lidptosis, eye drops containing the active ingredient apraclonidine can be used, Prof. Borelli reported [1]. Apraclonidine is an active substance from the group of sympathomimetics, which is actually used to treat glaucoma. For the treatment of lidptosis, the recommended dosage is 1-3 drops, up to 3× daily. The speaker points out that one should pay attention to the contraindications, which include, for example, taking monoamine oxidase inhibitors [1]. As general advice regarding possible side effects of Botox treatment, Prof. Borelli points out that it is always important to have a plan B to deal with any complications that may arise [1].
‘Gummy smile’ is among the rarer indications
The treatment of the gummy smile is also possible with Botox A. According to the guidelines, the neurotoxin is even the first choice therapy. The ‘gummy smile’ is an excessive gum exposure during smiling. The target of Botox treatment is the levator labii superioris alaeque nasi muscle and, if necessary, parts of the levator labii superioris and zygomaticus minor muscles. The injection is performed percutaneously, and the rather deep location of the target muscles should be noted [3]. The aim is to achieve the most perfect smile possible by balancing the three parameters ‘white’ (teeth), ‘pink’ (gums) and lips [6]. In a prospective study (n=14), in cases where more than 2 mm of gingiva was visible, bilateral injections with an average of 5 units at 3 injection sites (lip elevator muscle) with Botox A** resulted in 85% improvement [7].
** Onabotulinum toxin A
‘Facial feedback’ theory: Botox positively influences state of mind
“Depressed people show excessive facial muscle activity,” according to Prof. Borelli [1]. In international studies, antidepressant effects of botulinum toxin applied to the glabella in the frontal facial region were observed beyond the period of action of the neurotoxin. This is clear from a secondary analysis by Qian et al. which evaluated data from 5 randomized-controlled trials involving a total of 417 patients [8]. It was found that a statistically significant reduction in depressive symptoms was achieved in the Botox A groups. This can be explained by the so-called ‘facial feedback’ theory. Accordingly, the mimic expression of emotion and its proprioception reinforce the original emotion. The paralytic effect of Botox A on the frontal muscle groups involved in the expression of negative emotions is thought to be associated with antidepressant efficacy [9]. Botox A is therefore considered an experimental therapeutic option for major depressive disorder [10].
Congress: Training week for practical dermatology
Literature:
- “Botulinum toxin & fillers,” Prof. Claudia Borelli, M.D., 28th Advanced Training Week for Practical Dermatology and Venereology, July 12-17, 2022.
- Götz W: The face in old age, ZWP 9/2009, https://epaper.zwp-online.info/epaper/316/export-article/46,(last accessed 22.11.2022).
- S1 Guideline “Botulinum toxin therapy” (AWMF Registry No. 013-077). 2021 https://register.awmf.org,(last call 11/22/2022)
- Frevert J: Pharmaceutical, biological, and clinical properties of botulinum neurotoxin type A products. Drugs R D 2015; 15 (1): 1-9.
- Camargo CP, et al: Cochrane Database Syst Rev 2021 Jul 5;7(7):CD011301.
- Diaspro A, et al: Gummy Smile Treatment: Proposal for a Novel Corrective Technique and a Review of the Literature. Aesthet Surg 2018: 38(12): 1330-1338.
- Suber JS, et al: OnabotulinumtoxinA for the treatment of a “gummy smile”. Aesthet Surg 2014; 34(3): 432-437.
- Qian H, et al: Efficacy and Safety of Botulinum Toxin vs. Placebo in Depression: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Front Psychiatry 2020, Dec 4; 11: 603087.
- Bartova L, Winkler D: CliniCum neuropsy: special issue 2019; 1-6.
- “Treatment-resistant depression: diagnosis and treatment,” https://oegpb.%C3%..,(last accessed 11/22/2022).
- Alimohammadi M, Punga AR: Neurophysiological Measures of Efficacy and Safety for Botulinum Toxin Injection in Facial and Bulbar Muscles: Special Considerations. Toxins (Basel) 2017; 9(11): 352. Doi: www.mdpi.com/2072-6651/9/11/352/htm,(last accessed Nov 22, 2022).
