In the early 1990s, botulinum toxin type A secreted by Clostridium botulinum began to be used in cosmetic plastic surgery, which is highly favored due to its minimally invasive and high efficiency, and has been widely used in China in the past decade or so. However, as a highly toxic and deadly germ, the toxin secreted by Clostridium botulinum is one of the most toxic proteins, and the side effects should not be underestimated while using it to achieve cosmetic effects.
1. Mechanism of action.
BTX specifically combines with the presynaptic membrane of peripheral motor nerve endings to inhibit the release of acetylcholine from the presynaptic membrane to the neurotransmitter, thus causing flaccid paralysis of the innervated muscles and blocking the conduction of nerves and muscles, and at the same time delaying the production of new wrinkles, and after 3–6 months, the end plate of the neuromuscular junction returns to normal function. After 3 – 6 months, the neuromuscular junction end plate will return to normal function, and the clinical performance of wrinkles will return, so the effective time of one injection is about 4 – 8 months.
2.Main products.
At present, the main commercial A-type botulinum toxin widely used in clinical practice are BOTOX (BOTOX) from the United States and Hengli from China.
3.Indications.
The application of BTX in facial aging was initially used only for wrinkle reduction in the upper 1/3 of the face, such as frown lines, crow’s feet, head lines, etc., but now the scope is expanded to the full face and neck.
4.Implementation methods.
(1) Frontal transverse lines: frontal transverse lines are caused by excessive contraction of frontal muscles. According to the height and width of the patient’s forehead and the direction and depth of the frontal transverse lines, there are 4 injection methods, respectively injecting 5–7 points. The total amount of BTX injected is 12–18 U, and the maximum amount of BTX can be as high as 1.5–2 cm. — 18 U, up to 20 U.
(2) Interbrow lines: The first indication for FDA-approved BOTOX® injections for wrinkle reduction is interbrow lines. There are 4 muscles that form the frown lines. Classically, 4 or 5 dots are injected into the frown lines, including 4 dots between the eyebrows and 1 dot at the base of the nose, and 5 U of BTX is injected into each dot.
(3) Crow’s feet: Crow’s feet are often caused by photoaging, photodamage and excessive contraction of the muscle fibers of the lateral orbicularis oculi muscle, which is also called crow′s feet because of its radial shape. BTX can be injected directly into the lateral edge of the orbicularis oculi muscle at 1-1.5 cm from the outer edge of the orbit, with 2-4 U of BOTOX at each site, for a total volume of 8-20 U. Caution should be exercised when injecting to prevent injection into the blood vessels.
(4) Nasal interbrow lines: There are shallow wrinkles between the nose and eyebrows, and when the nose is lifted upward, nasal magnetic lines or rabbit nose lines appear. BTX 2–5 U can be injected into the lateral wall of the nose and bilateral nasofacial angle, which can make the nasobrow lines disappear.
(5) nasal tip sagging: surgical plastic surgery was previously used for nasal tip downward. Now non-invasive techniques can be used, such as the use of BTX injection into the nasal column (columella) to relax, the general injection dose of 4 – 5 U.
(6) Perioral lines: Perioral lines are both static (photoaging or photodamage) and dynamic (frequent smoking, playing musical instruments), with shallow radiolucent lines around the red lips. BTX 1–2 U can be injected at each 1/4 of the upper lip red edge, and BOTOX 1–2 U at each 1/4 of the lower lip red edge. The depth of injection should reach the junction of dermis and subcutaneous tissue.
(7) Bite muscle hypertrophy: Botox injection causes muscle wasting atrophy is the basic principle of treating bite muscle hypertrophy. Inject the needle at the angle of the jaw and fan out evenly to avoid injecting into the upper edge of the bite muscle.
5, adverse reactions and contraindications.
Botulinum toxin in a long period of clinical application although no serious adverse reactions were found reported, is a relatively safe drug. Side effects are temporary, often occurring 3 – 5 days after treatment, gradually fading after 2 – 4 weeks, mainly including eyelid drooping, orbital fat herniation, blurred vision, local edema petechiae, exposure keratitis, forehead tightness, upper lip sagging, expression is not natural, etc., some patients may have hair loss. Some patients may have systemic reactions such as fever, fatigue, malaise and discomfort. However, it has been reported that patients suddenly develop anaphylactic shock during or after injection, and can die rapidly if not rescued in time. Mild cases can be relieved by epinephrine injection; severe cases need to be resuscitated with fluids and oxygen, antihypertensive drugs, and anti-allergic drugs and adrenocorticosteroids.
Moreover, there are many contraindications to Botox injection: for patients with generalized muscle weakness, pregnant women, lactating women, infection at the injection site, allergy to human albumin, etc. should be listed as contraindications, among which pregnancy and lactation are prohibited. To date, it is not known whether the drug affects the fetus or the infant with lactation; and for diseases such as myasthenia gravis, Lambort-Eaton syndrome, and others, it should be used with caution due to the presence of severe neuromuscular transmission disorders. In addition, BTX was found to be enhanced by quinine, aminoglycoside antimicrobials and cyclomycin, which should also be used with clinical caution.
6. Precautions.
Before injection, the doctor should check the dosage carefully and operate strictly, and inject accurately into the muscles of the area to be wrinkle-free, starting treatment at least 1.5 cm above the orbital rim of the eyes. When selecting the injection sites, it is important to make sure that the distribution is symmetrical and that there is no deviation. If the injection sites are not set symmetrically, sagging of the eyebrows may occur, and if the injection sites at the crow’s feet are not set symmetrically, diplopia may occur.
The injection site should be photographed before treatment, and the patient should be instructed to try to contract the muscles in the area of the wrinkles and to take pictures when the wrinkles are most visible. After the effect of BOTOX injection, the camera should be taken again when the wrinkles disappear completely, and the size and direction of the camera should be exactly the same as before and after the treatment.
After the injection, the patient should avoid massaging the injection area for 2-3 hours; keep the injection site clean and dry for 6 hours; rest in a sitting position for 0.5- 1 hour before leaving the office after the injection.