You are in: eMedicine Specialties > Otolaryngology and Facial Plastic Surgery > COSMETIC SURGERY BOTOX® Injections to Improve Facial AestheticsArticle Last Updated: Oct 22, 2006AUTHOR AND EDITOR INFORMATIONSection 1 of 10
  Author: Pramit S Malhotra, MD, MS, Director, Malhotra Center for Plastic Surgery, PC Pramit S Malhotra is a member of the following medical societies: American Academy of Facial Plastic and Reconstructive Surgery, American Medical Association, and American Society of Plastic Surgeons Coauthor(s): Daniel G Danahey, MD, PhD, Consulting Staff, Michiana Eye Center and Facial Plastic Surgery, South Bend, Indiana; Peter Hilger, MD, Professor, Department of Otolaryngology, University of Minnesota Medical School Editors: Jennifer P Porter, MD, Clinical Associate Professor, Department of Otolaryngology - Head and Neck Surgery, Chevy Chase Facial Plastic Surgery; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, eMedicine; Keith A LaFerriere, MD, Clinical Professor, Fellowship Director, Department of Surgery, Division of Otolaryngology, University of Missouri at Columbia; Christopher L Slack, MD, Otolaryngology-Facial Plastic Surgery, Private Practice, Associated Coastal ENT; Medical Director, Treasure Coast Sleep Disorders; Arlen D Meyers, MD, MBA, Professor, Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine Author and Editor Disclosure Synonyms and related keywords: botulinum toxin, botulinum toxin A, Clostridium botulinum, hyperfunctional facial lines, BOTOX® injections, BOTOX®, crows feet INTRODUCTIONSection 2 of 10
  History Botulinum toxin is best known to clinicians as a deadly poison produced by the Clostridium botulinum bacterium. Only within the past 2 decades have clinical applications for this toxin surfaced. Originally, applicability was found for botulinum toxin in the treatment of strabismus; however, this single indication has now grown into many. Currently, the Food and Drug Administration (FDA) has approved botulinum toxin A for blepharospasm, strabismus, cervical dystonia, and the aesthetic improvement of glabellar rhytides. Common clinical uses Currently, botulinum toxin is most commonly used in the management of hyperfunctional lines. Previously, hyperfunctional lines were the source of much consternation for those affected by them. These lines often caused patients to be misinterpreted as angry, anxious, fearful, or fatigued. In the past, facial plastic surgeons only had surgical options in their armamentarium, including excision or implantation of fat, collagen, or silicone. These procedures often provided minimal improvement and exposed patients to the risks associated with surgery. Injections of botulinum toxin A provide an opportunity to manage these hyperfunctional lines with minimal morbidity. The 3 most common sites for injection are the glabella, periorbital crow's feet, and forehead areas. For excellent patient education resources, visit eMedicine's Procedures Center. Also, see eMedicine's patient education article BOTOX® Injections. PATHOPHYSIOLOGYSection 3 of 10
Etiology of hyperfunctional lines Hyperfunctional lines result from the contraction of the underlying facial musculature. The forehead is a complex of the frontalis muscle with insertions onto fibers of the procerus, corrugator, depressor supercilii, and orbicularis muscles. The frontalis muscle, responsible for the surprised appearance when acting unopposed, mediates elevation of the brow and is primarily responsible for horizontal wrinkles. Soft tissue laxity of the forehead and periorbital area causes brow ptosis and reflex contraction of the frontalis muscle to restore brow position, exacerbating forehead rhytids. Treatment of these rhytids with BOTOX® can increase brow ptosis. The frontalis muscle also can be responsible for the appearance of scowling. However, the main agent responsible for the appearance of scowling is the corrugator muscle. The normal function of the corrugator is as a brow adductor, bringing the eyebrow medial and inferior. Chronic contraction of the corrugator results in deep vertical hyperfunctional lines between the eyes, sometimes referred to as a glabellar crease. The depressor supercilii muscle pulls the medial brow inferior and medially. The last muscle in this group is the procerus muscle, which overlies the nasal root. Contraction of the procerus results in a snout-nose appearance and a horizontal rhytid at the nasal root. The anatomy of hyperfunctional lines in the orbit is intricate. Contraction of the orbicularis oculi muscle is primarily responsible for the clinically observed periorbital crow's feet. The orbicularis oculi muscle is bordered superolaterally by fibers of the frontalis muscle and medially by the levator palpebrae muscle. Injection of this area requires special cognizance of adjacent musculature to avoid upper lid ptosis. Pharmacology The Clostridium botulinum bacterium produces 7 distinct toxins lettered A through G. All 7 toxins are antigenically distinct; however, toxin A is most familiar to clinicians. Botulinum toxin A (BOTOX®) causes paralysis by inhibiting acetylcholine release at the neuromuscular junction. This is accomplished in 3 steps. First, the toxin binds the nerve. Second, the toxin is internalized into the nerve. Third, the toxin is cleaved by internal proteolytic enzymes, and the degradation byproducts interfere with the normal process of vesicle fusion to the plasma membrane. This results in the inhibition of the exocytosis of acetylcholine. The toxin requires 24-72 hours to take effect, reflecting the time necessary to disrupt the synaptosomal process. In very rare circumstances, some individuals may require as many as 5 days for the full effect to be observed. The dose of the toxin is measured as 1 standard unit, which is equal to the amount necessary to kill 50% of Swiss-Webster mice injected with that dose. The effect of botulinum toxin lasts 8-12 weeks. INDICATIONSSection 4 of 10
Current indications for BOTOX® injections include the following:
CONTRAINDICATIONSSection 5 of 10
Contraindications to BOTOX® injections include the following:
TREATMENTSection 6 of 10
Patient selection Several prospective studies by Blitzer et al and Pribitkin et al have examined the effectiveness of botulinum injections for hyperfunctional lines. From these studies, certain characteristics of successfully treated patients have been identified. The ideal patients have thin skin, fine wrinkles, lines that are exacerbated by muscle contraction, and hyperfunctional lines that can be spread out with their fingers. Blitzer et al describe a "glabellar spread test" in which the physician is able to spread out the hyperfunctional glabellar lines to project the maximum benefit that a paralytic injection could achieve. Candidates that have received minimal improvement from botulinum injections include those that failed the spread test, those with previous surgery near treated areas, those with thick skin or deep dermal scarring, and those with actinic skin changes. Facial lines resulting from the loss of dermal elasticity associated with aging are unlikely to respond to botulinum toxin injections. These areas are more appropriately treated with injectable fillers, which efface the static rhytids. Treatment Before the procedure is undertaken, a thorough history (including prior facial surgical procedures) and medication review are undertaken. Attention is focused on looking for those patients with contraindications as previously discussed. Preprocedure photographs often are taken by the individual surgeons' photography studio. A close-up photograph that isolates the area of interest should be taken, as well as a full-face photograph. Photographs are taken at rest and during muscle contraction. Botulinum toxin A (BOTOX®) arrives on dry ice and must be stored frozen at temperatures lower than -4°C. It comes in a 100-U bottle. One unit is defined as the median lethal dose in mice. The median lethal dose in humans is estimated at 3000 U. The toxin generally is mixed with 2.5 mL of 0.9% nonpreserved sterile saline solution, creating a concentration of 40U/mL. Carruthers et al, in an outstanding consensus panel article, noted that panel members agreed that preserved saline could also be used. An insulin syringe with a 30-gauge needle works nicely for injection. The insulin syringe does not waste any of the in the hub of the syringe. Some clinicians are moving to 32-gauge needles, which demonstrate better patient tolerance. The area of injection can be covered with topical anesthetic cream (eg, eutectic mix of local anesthetics [EMLA]) or can be anesthetized using ice. The solution then lasts up to 4 hours if refrigerated between injections, according to the manufacturer. Hexsel et alconducted a blinded multi-institution study and demonstrated that reconstituted BOTOX® retained its efficacy for up to 6 weeks when stored at 4°C. Studies by Blitzer et al and Carruthers et al, and the BOTOX® Consensus Group provide some very reasonable dose suggestions, as follows:
Electromyograph monitoring Many authors have chosen to perform their injections under the guidance of EMG monitoring. This technique involves using a 27-gauge (1.5 in) polytef-coated EMG needle connected to an EMG recorder by an alligator clip on its shaft. The patient is asked to contract the muscle in question. The injection is placed where the maximal EMG recording can be found within the muscle. This technique ensures that the injection is at the portion of the muscle that is contributing most to the hyperfunctional facial line. As these injections have become routine, many centers have obtained satisfactory results without EMG guidance. Many physicians use a readily available 30-gauge insulin syringe instead. However, EMG-guided injections remain a useful adjunct in patients who have residual function after their initial injection. Reinjection If a patient feels that little benefit was derived from the original injection, reinjection can be performed 1 week postinjection. However, 2-3 weeks postinjection is probably a more practical time for a return clinic visit. Generally, 2.5-5 U are used for reinjection. Reinjection strategies are still evolving. Once the patient has a satisfactory result, the next visit is at 2-3 months or when the patient requests another treatment. COMPLICATIONSSection 7 of 10
The most feared complication is temporary paralysis of nearby facial musculature. Approximately 1-3% of patients may experience a temporary upper lid or brow ptosis; the most troublesome complication to the patient is upper lid ptosis. This results from migration of the botulinum toxin to the levator palpebrae superioris muscle. The ptosis usually lasts 2-6 weeks. It can be treated with apraclonidine (Iopidine, Alcon). This is an alpha-adrenergic agent that stimulates the Müller muscle and immediately elevates the upper eyelid. This treatment usually can raise the eyelid 1-3 mm. The treatment of 1-2 drops 3 times per day continues until the ptosis resolves. Bruising can occur, particularly if a small vein is lacerated or a patient is taking aspirin, vitamin E, or NSAIDs. Ideally, patients should stop taking these products 2 weeks before the procedure. Headaches can occur after BOTOX® injections; however, in one study by Carruthers et al, this did not exceed the placebo group. This is thought to be due to the trauma of the injection and not something inherent in the toxin. In fact, botulinum toxin injections are extremely safe. To date, no significant long-term hazards of botulinum toxin injections have been identified in excess of placebo groups. FUTURESection 8 of 10
Future The popularity of BOTOX® is unmatched in cosmetic surgery. The utility and scope of botulinum toxin increases every year. Patients have shown a high degree of satisfaction with the procedure. Current research focuses on using BOTOX® as an adjunct to a myriad of surgical and ablative procedures. Botulinum toxin A now has been used in significant numbers for 20 years. Its injection has proved to be an extremely safe strategy for selectively inducing muscle paralysis. MULTIMEDIASection 9 of 10
REFERENCESSection 10 of 10
BOTOX® Injections to Improve Facial Aesthetics excerpt Article Last Updated: Oct 22, 2006 | ||||||||||||||||||||||||||||
