Skin filling. Collagen and other injectables of the skin.

Minimally invasive soft tissue augmentation of the face with injectable substances has been performed for more than a century. During this period, many substances have been used to cosmetically improve soft-tissue defects and deficiencies. Some have lasted; most have not. These procedures have become increasingly important as more patients seek aesthetic improvement without major surgical procedures. This article reviews the current status of these materials and techniques.

Complications and adverse reactions with the use of botulinum toxin.

Botulinum toxins are the causative agents of the severe food-borne illness botulism. With lethal doses approximating 10(-9) g/kg body weight, these neurotoxins represent some of the most toxic naturally occurring substances. Regardless, botulinum toxin is considered a safe therapy for inappropriate muscle spasms with adverse effects being typically self-limited. This article deals with some of the complications that have occurred with these treatments. The greatest concern with the use of BOTOX is probably the formation of blocking antibodies leading to nonresponse of subsequent treatment. Prevalence of resistance is less than 5%. Most complications associated with its aesthetic use are few and anecdotal. Nevertheless, the common problems and pitfalls associated with aesthetic treatment of the various areas of the face and neck with botulinum toxin are discussed. Also included are recommendations as to how to avoid these very undesirable, yet common, problems.

Collagen substances.

Soft tissue enhancement has become increasingly important as more patients seek aesthetic improvement without major surgical procedures. Injectable Zyderm bovine collagen has come to be regarded as the "gold standard" of injectable or implantable fillers, against which all other fillers are measured. This article describes the techniques of injection for bovine collagen and discusses the indications, allergenicity, and adverse responses. Other types of available collagen substances are also discussed.

Collagen substitutes: bovine collagen.

Injectable collagens (e.g., ZC-I, ZC-II, ZP) provide the physician with a manner for approaching mild contour defects. They are a temporary, biocompatible solution to many, but certainly not all, soft-tissue deficiencies. The adverse reaction profile is of an acceptably low level and indeed only of local significance. For the physician and patient to benefit from these agents, however, effective, reproducible implantation techniques must be developed by the treating physician. As the physician's experience with these agents increases, so will his or her ability to produce aesthetically pleasing results.

Proliferation of glial cells in vivo induced in the neural lobe of the rat pituitary by lithium.

Lithium salts are widely used for treatment of psychiatric illness. Lithium also affects cell proliferation. During investigation of the effect of lithium chloride on the central nervous system (CNS) of nephrectomized rats, we noted numerous mitotic figures in the neural lobe of the pituitary. Morphologic criteria established that the mitotic cells were astrocytes, the supporting glial cells of the CNS, also known as pituicytes. Equimolar doses of chlorides of chemically related cations (sodium, potassium, rubidium) had no such effect.

Dilution and storage of botulinum toxin.

BACKGROUND: There has been an ongoing controversy as to the best dilution for botulinum toxin for use in cosmetic applications. Recommended dilutions have ranged from 1 ml per vial to 10 ml per vial. There has also been much discussion on the diluent, i.e., preserved versus unpreserved saline, to be used and on storage time of the material after dilution. OBJECTIVES: The objective of this paper is to examine the literature and experience of practitioners in the field to try to resolve some of the questions concerning dilution and storage of botulinum toxin. CONCLUSIONS: Although there is great variation in the dilutions adopted by various physicians, much of this is a matter of personal preference. It does seem to appear that most clinicians use a dilution near 2.5 to 3.0 ml per vial and three-quarters of them limit the storage of the diluted product to 1 week or less.

Electromyographic guidance in injecting botulinum toxin.

BACKGROUND: Many practitioners involved with the cosmetic applications of botulinum toxin believe that electromyography (EMG) is an invaluable tool in determining the precise locations to inject. Others feel that it is unnecessary and of no value whatsoever. OBJECTIVES: The objective of this paper is to (1) demonstrate the proper technique for usage of the EMG machine, and (2) determine if its use in connection with injection of facial muscles for cosmetic purposes is worthwhile. CONCLUSIONS: The anatomy of the muscles of the face is somewhat variable from person to person. Electromyography can be a valuable adjunct when injecting botulinum toxin for cosmetic purposes by ensuring that the injecting needle is precisely in the muscle, thereby ensuring that the botulinum toxin will have the greatest possible effect.

Treatment of facial furrows and rhytides.

Many substances have historically been used to address facial soft tissue defects. Currently in the United States autologous fat and injectable bovine collagen are the most commonly utilized injectable fillers. Additionally, the judicious application of BOTOX in the upper face as well as neck has all but revolutionized the use of filling agents in these locales. While other agents are briefly mentioned, this is an in-depth review of the characteristics and application of autologous fat, bovine collagen.