Botox injection fundamental
Dr. Kamal Alhallak
- Administering Botox injection is an essential skill for physicians and qualified healthcare providers who wish to incorporate aesthetic medicine into their practice. According to statistics from the American Society of Plastic Surgeons, since its approval for cosmetic use by the U.S. Food and Drug Administration (FDA), Botox has become the most commonly performed minimally invasive cosmetic procedure, with over 3 million treatments performed annually. To successfully perform Botox procedures, an understanding of relevant anatomy and an appreciation for facial aesthetics, in addition to injection skill, are necessary to achieve desirable results.
- Skin Aging Wrinkling is a prominent feature of skin aging. Skin naturally thins and loses volume over time as dermal collagen, hyaluronic acid, and elastin gradually diminish. This process of dermal atrophy is accelerated and compounded by sun exposure and other extrinsic factors such as smoking. Hyperdynamic facial musculature also contributes to the formation of visible lines and wrinkles. Initially, lines and wrinkles are seen only during active facial expression such as frowning, laughing, or smiling and are referred to as dynamic lines (Fig. 1A). Over time, dynamic lines become permanently etched into skin resulting in static lines (Fig. 2B), which are present at rest. Skin laxity, redistribution of facial fat, and biometric changes such as bone resorption, contribute to skin folds and facial contour changes. In addition, aged skin exhibits dyschromia such as mottled pigmentation, vascular ectasias such as telangiectasias and cherry angiomas, and undergoes benign and malignant degenerative changes.
- Botox Indications (Year Approved) • Botox is FDA approved for the temporary treatment of moderate to severe dynamic glabellar frown lines in adults aged 18– 65 years (2002). • Botox is FDA approved for the temporary treatment of primary axillary hyperhidrosis (2004). • Other FDA approved indications include blepharospasm (1989), strabismus (1989), cranial nerve VII disorders (1989), cervical dystonia (2000), upper limb spasticity (2010), prophylaxsis for chronic migraine (2010). • Other off-label cosmetic uses include reduction of wrinkles in the upper and lower face, neck, and chest; lifting of facial areas; and correction of facial asymmetries.
- Mechanism of Action Botox is a neurotoxin protein derived from the Clostridium botulinum bacterium. When small quantities of Botox are injected into target muscles, localized chemical denervation occurs due to inhibition of acetylcholine release at the neuromuscular junction (Fig. 3). This temporarily reduces muscle contractions and smooths skin wrinkles in the treatment area.
- Basic and Advanced Procedures Basic. Areas of hyperdynamic muscles in the upper third of the face (frown lines, crow’s feet and horizontal forehead lines) yield the most predictable results with the greatest efficacy, and fewest reported side-effects when treated with botulinum toxin. These areas are ideal for providers getting started with cosmetic Botox injections and are referred to as basic treatment areas (Table 1) in this book. Advanced. Botox treatments in the lower face are considered advanced procedures (Table 1). This is a highly functional region and, in addition to facial expression, lower face muscles serve essential functions of mastication and elocution. Treated muscles in the lower face must retain partial functionality which requires more practiced injection skill with precise placement of small doses of toxin. Botox treatment of neck bands, hyperhidrosis and all facial areas other than the basic treatment areas, are considered advanced procedures in this book. These procedures have a greater risk of complications, and it is advisable for novice injectors to gain skill and confidence with basic procedures before proceeding to advanced Botox procedures.
- Patient Selection Patients with dynamic wrinkles that have minimal to no static component (Fig. 1) demonstrate the most dramatic improvements with Botox treatments. Results for patients with static wrinkles (Fig. 2) are slower and cumulative, and may require two to three consecutive treatments for significant improvements. Deep static lines may not fully respond to Botox treatment alone and may require combination treatment with dermal fillers or resurfacing procedures to achieve optimal results. Severe static wrinkles and laxity, commonly seen in patients aged 65 years or older, may require surgical intervention. Discussion regarding realistic expectations and results during the evaluation and consultation process is essential.
- Treatment Goals Botox treatments are directed at specifically targeted muscles or regions of muscles to focally inhibit contraction and achieve intended effects such as smoothing the skin or elevating facial areas. An optimal result yields a pleasing aesthetic effect with minimal to no functional impairment in the treatment area and, lack of other undesired effects and complications. The degree of muscle inhibition achieved with Botox in a given treatment area is determined by patient preference and the need to preserve functionality in the treated muscles. For example, some patients may desire complete inhibition of the glabellar complex muscles with Botox treatment of frown lines, whereas others may desire partial muscle inhibition with retention of some ability to frown. A greater degree of muscle inhibition is typically sought for treatments in the upper third of the face than in the lower face. In the lower face, partial muscle inhibition is the desired result as the treated muscles must still be able to perform essential functions, such as eating, drinking, and speaking. Treatment goals listed in the following chapters are based on common patient preferences and considerations of muscle functionality in the treatment areas.
- Products C. botulinum bacteria produce eight serotypes of Botox proteins (A, B, Cα, Cβ, D, E, F, and G). Botox serotype A is the most potent and is used for cosmetic indications. The FDA currently approve two Botox serotype A products for the treatment of the glabellar complex muscles that form frown lines: onabotulinumtoxinA (OBTX) (Botox ® manufactured by Allergan, Inc, Irvine, CA) and abobotulinumtoxinA (Dysport ® manufactured by Medicis Pharmaceutical Corp, Scottsdale, AZ), both of which were formerly known as Botox type A. OBTX and abobotulinumtoxinA vary in formulation, diffusion capability, onset of action, efficacy, and complications and are not interchangeable.
- Contraindications • Pregnancy or nursing • Active infection in the treatment area (e.g., herpes simplex, pustular acne, cellulitis) • Hypertrophic or keloidal scarring • Bleeding abnormality (e.g., thrombocytopenia, anticoagulant • Impaired healing (e.g., due to immunosuppression) • Skin atrophy (e.g., chronic oral steroid use, genetic syndromes such as Ehlers-Danlos syndrome) • Active dermatoses in the treatment area (e.g., psoriasis, eczema) • Sensitivity or allergy to constituents of Botox (including Botox serotype A, human albumin, lactose, or sodium succinate) • Milk allergy with abobotulinumtoxinA products • Gross motor weakness in the treatment area (e.g., due to polio, Bell’s palsy) • Neuromuscular disorder including, but not limited to amyotrophic lateral sclerosis, myasthenia gravis, Lambert-Eaton syndrome, and myopathies • Inability to actively contract muscles in the treatment area prior to treatment • Periocular or ocular surgery within the previous 6 months (e.g., laser-assisted in situ keratomileusis, blepharoplasty) • Medications that inhibit neuromuscular signaling and may potentiate Botox effects (e.g., aminoglycosides, penicillamine, quinine, calcium channel blockers) • Uncontrolled systemic condition • Occupation requiring uncompromised facial expression (e.g., actors, singers) • Unrealistic expectations or body dysmorphic disorder Advantages • Technically straightforward with short treatment time • Safe and effective, particularly in the upper third of the face • High patient satisfaction Disadvantage • Short duration of action relative to other cosmetic procedures, although effects may be cumulative over time with recurring treatments