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Anatomy and Botulinum Toxin Injections

Section Editor(s): Gruber, Ronald P. M.D.; Review Editor

Plastic and Reconstructive Surgery: November 2011 - Volume 128 - Issue 5 - p 1149–1150
doi: 10.1097/PRS.0b013e3182311baa

As a service to our readers, Plastic and Reconstructive Surgery® reviews books, DVDs, practice management software, and electronic media items of educational interest to reconstructive and aesthetic surgeons. All items are copyrighted and available commercially. The Journal actively solicits information in digital format (e.g., CD-ROM and Internet offerings) for review.

Reviewers are selected on the basis of relevant interest. Reviews are solely the opinion of the reviewer; they are usually published as submitted, with only copy editing. Plastic and Reconstructive Surgery® does not endorse or recommend any review so published. Send books, DVDs, and any other material for consideration to: Ronald P. Gruber, M.D., Review Editor, Plastic and Reconstructive Surgery, UT Southwestern Medical Center, 5323 Harry Hines Boulevard, HD1.544, Dallas, Texas 75390-8820.

Anatomy and Botulinum Toxin Injections is a handy, detailed, soft-cover atlas/text that is divided into 10 chapters based on the muscles of the face and neck that might benefit from botulinum injections. It is accompanied by a DVD. As the authors state in the Preface, each chapter represents a muscle, and each muscle is reviewed from a similar perspective, beginning with a description of the muscle and ending with injection technique and dosage. Sections 3 through 5 of each chapter contain beautiful cadaver dissections that are valuable for any physician operating on or treating facial structures. Indeed, the artwork and accompanying cadaver dissections are the most valuable aspects of this book and are unlike any other botulinum injection reprints that we know of. The book fills a void in appreciating facial anatomy as it relates to botulinum toxins.



Although we enjoyed and highly recommend this atlas on a global scale, we have some concerns. There are no references and no index, which may not always be a requirement for this type of format but would have helped confirm the anatomical findings and locate for the reader additional resources. Conversely, the inclusions of muscle innervations and the location of motor end plates are too detailed and, although anatomically interesting, clinically somewhat irrelevant. To their credit, the authors do include both commercially available neurotoxins and the corresponding units that they prefer. However, they omitted their reconstitution, their recommended conversion ratio between Botox and Dysport (which appears to be 1:2.5), and their technique of injecting small and precise amounts. Furthermore, there is little rationalization in their dosing guidelines and if they believe, as is implied in the book, that different toxins have the same injection sites, that should be stated. Also, they frequently recommend inserting the needle to the bone and withdrawing “1-2 mm” back into the belly of the muscle. Although that maneuver may assist proper placement for a novice injector, it tends to be more painful to the patient and moreover is worrisome when treating small muscles or those that overlie adjacent muscles.

On a regional level, the authors state “never inject the inferior portion of the frontalis muscle.” Few dogmas in medicine are absolute, and in theory this may have some validity, but in reality, the inferior fibers of this muscle interdigitate with the lateral fibers of the corrugator supercilii, and it would be futile to truly isolate them. They also initially state that these inferior injections should be “1 to 2 cm above the orbital superior border to reduce the risk of ptosis”; five pages later, that margin of safety is changed to “2 to 3 cm.” It should be acknowledged that some patients accept a lowered brow if all rhytides are ameliorated (this is one of the most important discussions we have with any patient considering frontalis muscle treatment). In this discussion, they mention the levator palpebrae muscle, a muscle that many associate with eyelid ptosis, but it cannot be found on any of their very nice dissections or illustrations. The authors devote three separate chapters to the anatomy of the glabellar complex with a total of 10 injection sites (approximately double the number that is generally suggested) to treat this aesthetic unit. A considerable amount of space is devoted to these individual muscles, inclusive of a chapter on the somewhat obscure depressor supercilii, a muscle that is often considered to be the medial fibers of the orbicularis oculi. However, it is frustrating that they do so to the complete exclusion of all nasal musculature.

When treating the orbicularis oculi muscle, it is unclear why this is the sole area where there is a disparity in the number of injection sites for the two toxins. As this text is also designed to help even the novice injector, the brow depressor activity of the lateral superior fibers of the orbicularis oculi and the consequent brow elevation with their inactivation should have been emphasized. In addition, the authors state that treating the inferior fibers of the orbicularis oculi often “treats the tear trough depression.” What would have been more informative and more accurate is if they had stated that a preinjection snap test is warranted to ensure adequate skin recoil and that weakening these fibers may widen the ocular aperture and reduce some of the dynamic fine infraocular rhytides.

Weakening the muscles in the lower two-thirds of the face (i.e., “extended” use of botulinum toxin) is usually not considered alone or what is referred to as monotherapy and is often used in combined therapy with adjunctive soft-tissue augmentation and/or lasers. This concept is also not mentioned. Imprecision or excessive toxin administration particularly in this area can result not only in an aesthetic deformity but also in functional impairment, and this should have been reinforced. The location, function, and resultant rhytides of the levator labii superioris alaeque nasi muscle seem to coincide exactly with what would be expected of the nasalis muscle. Nevertheless, the authors do correctly state that inactivation of this small muscle (levator labii superioris alaeque nasi) blunts the upper third of the nasolabial fold but, importantly, they do not mention that as a consequence it can also blunt the cupid's bow.

It is also surprising that they did not mention that treating this small muscle can help to improve a “gummy smile.” No mention is made of the role of botulinum toxin for the plunging nasal tip or postrhinoplasty transverse upper lip rhytide. Moreover, not much is discussed about facial reshaping with botulinum toxin.

Locating and treating the depressor anguli oris can be difficult and, although they do caution assiduous avoidance of the depressor labii inferioris, the three injection sites that they show seem to be in the general vicinity of both the platysma and the masseter muscles. The latter masseter muscle, although not routinely treated, should have been included in the diagrams and the corresponding injection pattern, as masseter hypertrophy treatment is a frequent concern in certain populations.

Despite the aforementioned critiques, Drs. Fabio Ingallina and Patrick Trévidic have provided wonderful facial muscle dissections and illustrations accompanied by live models depicting the majority of the important facial muscles that are essential to properly injecting botulinum toxin. They are to be commended for taking this procedure to a new three-dimensional level and, although the injection sites and technique may not be universally adopted, the text is an excellent asset to those injectors, novice and experienced, interested in learning about facial musculature as it relates to the aesthetic surgeon. Finally, it will serve as a handy reference when “brushing up” on muscular facial anatomy or as a teaching tool for educating patients.

Alan Matarasso, M.D.

Seth Matarasso, M.D.

©2011American Society of Plastic Surgeons