PRF in Facial Esthetics E-Book

Catherine Davies

• Herausgeber: Quintessence Publishing Co, Inc
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 356

Veröffentlichungsjahr: 2020

Beschreibung

Facial esthetics has become one of the fastest-growing industries in the world. As the field continues to evolve and patients demand more and more of practitioners, it is clear that both the beginner as well as the advanced practitioner seek convenient, safe, and effective therapies, and this book provides just that. Written in collaboration with international experts from various fields of medicine, including basic scientists, clinician-scientists, experts in laser therapy and photography, as well as plastic surgeons and hair restorative surgeons, this book collectively offers a comprehensive approach to using platelet-rich fibrin (PRF) in facial esthetics. PRF has been used for decades in regenerative medicine, and slowly it has made its way into the medical esthetic arena, often used in combination with other leading therapies to support minimally invasive esthetic procedures. This book therefore starts at the beginning, first exploring the biology and anatomy of the skin and hair before turning to a discussion of photographic record-keeping and patient consultation. Then follow chapters on the biology of platelet concentrates and microneedling, skin and hair regeneration, lasers, and the use of PRF in plastic surgery. The final chapter looks to the future and considers what else could be possible. If you perform any facial esthetic procedures in your office or want to learn how, this book is a must.

Leseprobe

PRF in Facial Esthetics

Library of Congress Cataloging-in-Publication Data

Names: Davies, Catherine, author. | Miron, Richard J. (Richard John), 1983- author.

Title: PRF in facial esthetics / Catherine Davies, Richard J. Miron.

Other titles: Platelet-rich fibrin in facial esthetics

Description: Batavia, IL : Quintessence Publishing Co, Inc, [2020] | Includes bibliographical references and index. | Summary: “This book gathered numerous experts across many fields to collectively provide information on leading esthetic PRF therapies to expand treatment possibilities”-- Provided by publisher.

Identifiers: LCCN 2020009383 | ISBN 9780867159578 (hardcover)

Subjects: MESH: Face | Cosmetic Techniques | Fibrin--therapeutic use | Platelet-Rich Fibrin | Skin Aging | Rejuvenation | Esthetics, Dental

Classification: LCC RD119 | NLM WE 705 | DDC 617.9/52--dc23

LC record available at https://lccn.loc.gov/2020009383

© 2020 Quintessence Publishing Co, Inc

Quintessence Publishing Co, Inc411 N Raddant RoadBatavia, IL 60510www.quintpub.com

All rights reserved. This book or any part thereof may not be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, or otherwise, without prior written permission of the publisher.

Editor: Leah HuffmanDesign: Sue ZubekProduction: Angelina Schmelter

To Dr David Koski

When I moved to the United States 3 years ago, somehow you convinced me to think BIG. You took time out of your schedule to mentor me, volunteered many of your hours freely to support our education programs, and have been supportive beyond my comprehension. You called me Lebron when I didn’t understand. You taught me to “scale” when I knew only science. And you provided endless advice on topics I never considered relevant. I never expected to find such a wonderful role model and mentor, all calmly behind the scenes. You never asked for recognition. I have no words to express my gratitude and wanted to somehow show my appreciation. I therefore dedicate this book to you, Dr Koski. This one is for you, big guy! —RJM

Contents /

Preface

Acknowledgments

Contributors

 1 / Introduction to Facial Esthetics and PRF

Richard J. Miron and Catherine Davies

 2 / Facial Anatomy, Skin Biology, and the Effects of Aging

Catherine Davies and Richard J. Miron

 3 / Photography in Facial Esthetics

Walter Rozen, Richard J. Miron, and Catherine Davies

 4 / Consultation for the Facial Esthetic Patient

Richard J. Miron and Catherine Davies

 5 / Consultation for the Hair Loss Patient

Alan J. Bauman, Catherine Davies, and Richard J. Miron

 6 / Use of Platelet-Rich Fibrin in Facial Esthetics

Richard J. Miron, Yufeng Zhang, Ana Paz, Masako Fujioka-Kobayashi, and Catherine Davies

 7 / Biology of Microneedling

Erin Anderson, Nichole Kramer, Richard J. Miron, Ana Paz, and Catherine Davies

 8 / Injection Techniques with Platelet-Rich Fibrin

Catherine Davies, Ana Paz, Alireza Panahpour, Ana Cristina, and Richard J. Miron

 9 / Hair Regeneration with Platelet-Rich Fibrin

Catherine Davies and Richard J. Miron

10 / Lasers in Facial Esthetics

Ana Paz, Harvey Shiffman, Miguel Stanley, Catherine Davies, and Richard J. Miron

11 / Skin Care Products and Their Effect on Aging Skin

Geir Håvard Kvalheim, Catherine Davies, and Richard J. Miron

12 / Future Trends in Esthetic Medicine

Carlos Fernando de Almeida Barros Mourão, Delia Tuttle, Ruth Delli Carpini, Scott Delboccio, Richard J. Miron, and Catherine Davies

Index

Preface /

Facial esthetics has become one of the fastest-growing industries in the world. The esthetic demand for patients worldwide has never been higher, leading to this multibillion-dollar, booming industry. As the field continues to evolve, it is important that all medical practitioners are able to provide solid, evidence-based procedures while minimizing complications. Platelet concentrates have long been utilized in regenerative medicine, and over the years, the removal of anticoagulants has further improved their safety and effectiveness. Today, platelet-rich fibrin (PRF) has nearly replaced platelet-rich plasma in many fields of medicine and has gradually made its way into the medical esthetic arena. Furthermore, its use has been combined with other leading therapies to expand treatment possibilities. As trends continue to support minimally invasive esthetic procedures, it is clear that both the beginner as well as the advanced practitioner seek convenient, safe, and effective therapies.

This textbook is a first of its kind and an introduction to PRF in facial esthetics. The book was a true joy to put together, as many international experts in various fields of medicine have tremendously improved the quality of the final chapters. It has been a privilege to collaborate with basic scientists, the developers and clinician-scientists of microneedling, leading experts in laser therapy and low-level laser therapy, experts in photography, as well as plastic surgeons and hair restorative surgeons. This book is truly unique in that it gathered numerous experts across many fields with the ultimate goal of collectively providing as much knowledge on this topic as possible. We are therefore thrilled to present the first edition of our textbook, PRF in Facial Esthetics, and we look forward to your future feedback.

Acknowledgments /

We greatly acknowledge the tremendous contributions of our coauthors. Each of your specific expertise has been greatly valuable, and what a privilege to continue to work with each of you. The field will certainly continue to progress, and we sincerely enjoy our collaborations with each of you.

We equally want to thank Quintessence Publishing for their trust, commitment, and devotion to this project. Thank you to Bryn Grisham (Director of Book Publications), Leah Huffman (Senior Editor and Deputy Editorial Director), Angelina Schmelter (Senior Digital & Print Production Specialist), and William Hartman (Executive Vice President & Director). The quality work at Quintessence Publishing and the attention to detail regarding the preparation of this manuscript are truly special.

To the team at KVM Publishing who originally designed and provided some of the anatomical illustrations in this book, thank you. In particular, we thank Gerhard Sattler and Uliana Gout for laying the groundwork with their fantastic book on facial fillers.

To Advanced PRF Education at prfedu.com and all of its staff members, including Erin Anderson and Nichole Kramer from Dermapen, thank you for making teaching and education a top priority filled with exciting new challenges and ongoing learning experiences.

From Catherine Davies

I would like to express special thanks and gratitude to my amazing family—Paco, Zahra, Cuba, and Lila—for putting up with all the long working hours this year.

I would also like to thank Dr Richard Miron for his belief in me and for his invaluable guidance and advice during the writing of this book.

From Richard J. Miron

To my parents and family: Your unconditional love and support during this past year never goes unnoticed. Thank you for everything!

To Dr Catherine Davies: It has been a true joy and pleasure to work with you. Your bubbly personality and easy-to-understand teaching style is enlightening and seems to perfectly blend with my serious and rigorous scientific approach. I’ve enjoyed every moment of it—let’s keep going!

To Leah Huffman: How we managed three books together in 1 year is not something I could ever have imagined. Thank you endlessly for being dedicated, passionate, punctual, and simply the most outstanding and prolific editor!

Contributors /

Erin Anderson

Master Aesthetician

AO Surgical Arts

Salt Lake City, Utah

Director of Education

Dermapen

Alan J. Bauman, MD

Private Practice Specializing in Hair Transplant Surgery

Boca Raton, Florida

Ana Cristina, DDS, MSc

Private Practice Specializing in Facial Esthetics, Implantology, and Oral Maxillofacial Surgery

São Paulo, Brazil

Catherine Davies, MBBCh, MBA

Private Practice Specializing in Facial Esthetics

Johannesburg, South Africa

Scott Delboccio, DMD

Private Practice

Naples, Florida

Ruth Delli Carpini, DMD

Private Practice Specializing in Cosmetic Dentistry and Facial Esthetics

Milan, Italy

Masako Fujioka-Kobayashi, DDS, PhD

Research Associate

Department of Cranio-Maxillofacial Surgery

University Hospital of Bern

University of Bern

Bern, Switzerland

Nichole Kramer

Medical Aesthetician and Clinical Manager

Utah Body and Soul

Holladay, Utah

Co-director of Education

Dermapen

Geir Håvard Kvalheim

Founder of Čuvget

Tromsø, Norway

Richard J. Miron, DDS, BMSc, MSc, PhD, Dr med dent

Group Leader, The Miron Research Lab

Lead Educator, Advanced PRF Education

Venice, Florida

Carlos Fernando de Almeida Barros Mourão, DDS, MSc, PhD

Private Practice

San Pedro, California

Alireza Panahpour, DDS

Private Practice Specializing in Cosmetic Dentistry

Los Angeles, California

Ana Paz, DDS, MS

Private Practice

Lisbon, Portugal

Walter Rozen

Professional Photographer

Venice, Florida

Harvey Shiffman, DDS

Private Practice Specializing in Laser Therapy

Boynton Beach, Florida

Miguel Stanley, DDS

Private Practice

Lisbon, Portugal

Delia Tuttle, DDS, MD

Private Practice

Lake Elsinore, California

Yufeng Zhang, MD, DDS, PhD

Professor, Department of Dental Implantology

School of Stomatology

Wuhan University

Wuhan, China

1 /

INTRODUCTION TO FACIAL ESTHETICS AND PRF

Richard J. Miron

Catherine Davies

Facial esthetics has become one of the fastest-growing industries in the world. While originally a number of minimally invasive procedures were utilized effectively in facial esthetics (including Botox [Allergan], hyaluronic acids, and polydioxanone [PDO] threads), more recently platelet concentrates have gained momentum because of their more natural regenerative approach. The main advantage of platelet concentrates is that they offer a safe, easy-to-obtain, and completely immune-biocompatible method for the healing or regeneration of aging skin. This differs significantly from previous modalities that aim to act as fillers or paralyzers, which initiate a foreign body reaction once placed within living tissue. As the population continues to age and becomes more concerned with their esthetic appearances, more and more clinicians and practitioners wish to offer patients a natural approach with platelet concentrates and more specifically platelet-rich fibrin (PRF). As trends continue to support minimally invasive esthetic procedures, it is clear that both beginner as well as advanced practitioners seek convenient, safe, and effective therapies. Platelet-rich plasma (PRP) was the first platelet concentrate utilized in facial esthetics because of its supraphysiologic accumulation of platelets and their respective growth factors, known stimulators of tissue regeneration. However, one of its main limitations is its incorporation of anticoagulants, known inhibitors of wound healing. Today, with advancements in centrifugation protocols and centrifugation tube characteristics, it has become possible to utilize a liquid injectable PRF without incorporation of anticoagulants. This formulation has been studied and utilized extensively in various fields of medicine and has become increasingly popular in facial esthetics. This textbook provides a first-of-its-kind introduction to the use of PRF in facial esthetics.

Aging of the Skin

Aging of the skin is an inevitable process that gradually occurs as we get older1,2 (Fig 1-1). Several factors have been associated with this process, including both genetic and environmental factors.3 Exposure to sun, pollution, and various chemicals have been known to cause skin and/or DNA damage, speeding the aging process.3 A number of changes to the skin may occur as a result, including skin atrophy, telangiectasia, fine and deep wrinkles, yellowing (solar elastosis), and dyspigmentation.3 Furthermore, poor diet, lack of exercise, caffeine intake, smoking, and drug use are additional factors known to speed the aging process.4

FIG 1-1

The process of skin aging. With age, facial features tend to sag, with a volume shift downward of facial tissues.

One key element certainly important for overall health and particularly skin attractiveness is hydration. Dehydration of the skin may lead to epithelial cell apoptosis and flaky skin complexion. From this standpoint, skin dehydration is a major risk factor for skin aging, and many topical applications, including hyaluronic acid creams, are geared toward water retention as a modality to prevent dryness of the skin. Aging skin is also related to a number of obvious demarcations of the face (see chapter 2). Depressions in the corners of the mouth, cheeks, forehead, eyebrows, eyelids, and nose are all associated with aging5 (Box 1-1; see Fig 1-1). Based on visible differences that occur with aging, a variety of treatment options have been proposed to favor a more youthful appearance, but hydration is a key feature.

BOX 1-1

Progressive changes expected in normal aging

• Corners of the mouth move inferiorly, resulting in a slight frown look

• Cheeks sag inferiorly, resulting in the appearance of jowls

• Tissue around the eyes sags inferiorly

• Eyelids (upper and lower) sag inferiorly

• Tissue of the forehead drifts inferiorly, creating wrinkles and dropping the eyebrows downward with flatter appearances

• Nose may elongate and the tip may regress inferiorly

• Nose may develop a small to pronounced dorsal hump

• Tip of the nose may enlarge and become bulbous

• Generalized wrinkling to the face naturally occurs

As the body ages, it undergoes many changes that directly impact the physiology of human tissues, resulting in lower cellular activity.6 These changes include a loss in density, increases in fat storage, and lower production of collagen. A reduction in collagen synthesis as well as its associated increase in collagen degradation both have apparent disadvantages leading to a net loss of facial volume, resulting in skin folds and wrinkles7 (see chapter 2). Based on these changes associated with aging, several years ago it was proposed that platelet concentrates could be utilized in facial esthetics to improve collagen synthesis and restore facial volume.8–10 The main function of platelet concentrates is to increase recruitment and proliferation of cells and to further speed revascularization/blood flow toward defective areas. Many advancements have been made since the first-generation platelet concentrate—platelet-rich plasma (PRP). Several devices and isolation kits have since been fabricated based on the concept of isolating platelets for regenerative purposes, eliminating the inclusion of anticoagulants and speeding the preparation protocols. This second-generation platelet formulation, termed platelet-rich fibrin (PRF), has formed the basis for more than 600 scientific publications on the topic and has now extended into the field of facial esthetics. This textbook addresses this topic in detail and introduces the concept of PRF as a safer, more effective regenerative platelet concentrate that is 100% natural and thereby prevents a foreign body response.

Traditional Methods for Facial Rejuvenation

One of the first methods proposed for facial rejuvenation incorporated acupuncture.11 This concept was derived based on accumulating evidence that trauma to the skin in the form of a needle and/or syringe, dermal roller, or more recently microneedling (see chapter 7) could induce slight tissue damage leading to new angiogenesis, growth factor release, and subsequent new tissue regeneration. This tissue regeneration resulted in a more youthful appearance.

Because of the popularity of such treatments in facial esthetics and rapidly increasing trends in the field, more invasive techniques have also been proposed. These include facelifts, aggressive laser treatment modalities, and various grafting procedures.12–14 One of the advantages of platelet therapies is their ability to be used in combination with microneedling (see chapter 7), lasers (see chapter 10), plastic surgery (see chapter 12), and hair restoration (see chapter 9) simply to improve healing outcomes.

Traditional Biomaterials for Facial Rejuvenation

While various protocols and injectable materials have been proposed in facial esthetics, patients generally seek more natural regenerative approaches with the shortest possible downtime. In addition, medicine has gradually and naturally progressed toward more minimally invasive procedures. Today, many different agents and biomaterials can be utilized to accomplish this task, including Botox, fillers (eg, silicone, calcium hydroxyapatite, polymethyl methacrylate, hyaluronic acid products, hyaluronic acid + calcium hydroxyapatite, polylactic acid), various laser therapies at different wavelengths/intensities, and polydioxanone (PDO) threads.15–21 These products and modalities have been made popular by extensive marketing and celebrity endorsements and have been demonstrated to be successful in various esthetic procedures to improve cosmetic appearance (Box 1-2).

BOX 1-2

Unesthetic features that can be treated or eliminated with esthetic medicine procedures

• Scars

• Skin laxity

• Wrinkles

• Moles

• Liver spots

• Excess fat

• Cellulite

• Unwanted hair

• Skin discoloration

• Spider veins

Importantly, however, these techniques heavily rely on normal protective mechanisms of the epidermis, which can be altered or disrupted following their use. The use of Botox, for example, has shown secondary effects that may cause a cascade of reactions with potential consequences.22 Botox causes temporary denervation and relaxation of muscles by preventing the release of the neurotransmitter acetylcholine at the peripheral nerve endings.23 Clinicians generally recommend repeated injections every 6 months or so to maintain the facial appearance, but these injections may lead to secondary effects associated with an increased granular layer or thinning of the epidermis as a result of a foreign body reaction to this material.24,25 Other reported secondary effects include cases of muscle paresis including muscle weakness, brow ptosis, upper and/or lower eyelid ptosis, lateral arching of the eyebrow, double or blurred vision, loss or difficulty in voluntary eyelid closure, upper lip ptosis, uneven smile, lateral lip ptosis, lower lip flattening, orbicularis oris weakness, difficulty in chewing, dysphagia, altered voice pitch, and neck weakness. And dermal fillers have been associated with over 40 cases of blindness!

Despite the potential for negative outcomes, Botox and dermal fillers are generally considered safe and effective (Box 1-3). Nonetheless, such cases of blindness and ptosis are sure to create some fear within the community. Therefore, other materials (especially those with limited complications) are constantly being investigated as potential alternatives that do not bear significant secondary side effects. The goal of therapy with PRF is not to replace these previously utilized materials but simply to offer an additional and safer modality to the field that regenerates tissues naturally (Fig 1-2a) as opposed to filling or paralyzing tissues unnaturally (Fig 1-2b). PRF therapy therefore offers a natural regenerative approach with natural-looking outcomes (see Fig 1-2a). While each of the previously utilized materials offers its respective advantages and limitations (like any material), it is important to note that each is also foreign to the body and creates an additional inflammatory response when entering the body. These products have certainly demonstrated low patient morbidity and complication rates, but less invasive therapies offer a decreased risk of potential complications and a reduction in patient fear. This is often heavily favored by new patients wishing to enter their first facial esthetic regimen.

BOX 1-3

Safety of Botox and dermal fillers

These materials have been utilized in millions of patients with relatively few serious adverse effects. While there have been some negative case reports, medical use of Botox and fillers is generally considered safe and effective. Proper training and use of high-quality products (ie, approved materials) are recommended.

FIG 1-2

Esthetic medicine focuses on improving cosmetic appearance via a variety of procedures aimed at restoring the patient’s youthful look. (a) PRF naturally regenerates tissues, resulting in a natural-looking outcome. (b) Dermal fillers, on the other hand, fill tissues unnaturally, resulting in a less natural- looking appearance. Full lips in women are often considered attractive and desirable in modern society, and lip augmentation with fillers is the traditional method by which to achieve that look.

Esthetic Medicine

The field of esthetic medicine typically encompasses three specialties: (1) plastic surgery, (2) dermatology, and (3) reconstructive surgery. These specialties offer both surgical and nonsurgical esthetic procedures to improve cosmetic outcomes (Box 1-4), and these procedures can improve quality of life, psychologic well-being, and social function for many patients. It is now estimated that roughly 16 million esthetic procedures are performed annually in the United States alone, as reported by the American Society of Plastic Surgeons26 (Fig 1-3). Furthermore, reports have estimated that one billion people worldwide seek out solutions to help their facial and neck skin appear more youthful. This demand for facial esthetic procedures is only expected to further increase, as the skin care products market is valued at $177 billion annually.

BOX 1-4

Procedures in esthetic medicine

Surgical

• Liposuction

• Facelift

• Breast implants

• Radiofrequency abrasion

Nonsurgical

• Mesotherapy

• Radiofrequency skin tightening

• Nonsurgical liposuction

• Chemical peel

• Laser treatment

FIG 1-3

Number of minimally invasive procedures performed annually in the United States, a total of 16 million. (Adapted from the American Society of Plastic Surgeons.26)

Therefore, the ability to offer a more natural, autologous concentrate of growth factors derived from peripheral blood offers a very easy-to-obtain and low-cost method to regenerate facial tissues for patients. These less-invasive procedures have further become a norm in combination with microneedling, facial skin rejuvenation procedures, and hair restoration. Blood concentrates offer the ability to reach supraphysiologic doses of growth factors and cells responsible for the healing of various tissues using a natural healing approach.

References

1. Branchet M, Boisnic S, Frances C, Robert A. Skin thickness changes in normal aging skin. Gerontology 1990;36:28–35.

2. Helfrich YR, Sachs DL, Voorhees JJ. Overview of skin aging and photoaging. Dermatology Nursing 2008;20:177.

3. Herbig U, Ferreira M, Condel L, Carey D, Sedivy JM. Cellular senescence in aging primates. Science 2006;311:1257–1257.

4. Puizina-Ivi N. Skin aging. Acta Dermatoven APA 2008;17:47.

5. Friedman O. Changes associated with the aging face. Facial Plast Surg Clin North Am 2005;13:371–380.

6. Dimri GP, Lee X, Basile G, et al. A biomarker that identifies senescent human cells in culture and in aging skin in vivo. Proc Natl Acad Sci U S A 1995;92:9363–9367.

7. Lorencini M, Brohem CA, Dieamant GC, Zanchin NI, Maibach HI. Active ingredients against human epidermal aging. Ageing Res Rev 2014;15:100–115.

8. Kim DH, Je YJ, Kim CD, et al. Can platelet-rich plasma be used for skin rejuvenation? Evaluation of effects of platelet-rich plasma on human dermal fibroblast. Ann Dermatol 2011; 23:424–431.

9. Redaelli A. Face and neck revitalization with platelet-rich plasma (PRP): Clinical outcome in a series of 23 consecutively treated patients. J Drugs Dermatol 2010;9:466–472.

10. Na JI, Choi JW, Choi HR, et al. Rapid healing and reduced erythema after ablative fractional carbon dioxide laser resurfacing combined with the application of autologous platelet-rich plasma. Dermatol Surg 2011;37:463–468.

11. Barrett JB. Acupuncture and facial rejuvenation. Aesthet Surg J 2005;25:419–424.

12. Ramirez OM, Maillard GF, Musolas A. The extended subperiosteal face lift: A definitive soft-tissue remodeling for facial rejuvenation. Plast Reconstr Surg 1991;88:227–236.

13. Rohrich RJ, Ghavami A, Lemmon JA, Brown SA. The individualized component face lift: Developing a systematic approach to facial rejuvenation. Plast Reconstr Surg 2009;123:1050–1063.

14. El-Domyati M, Medhat W. Minimally invasive facial rejuvenation: Current concepts and future expectations. Exp Rev Dermatol 2013;8:565–580.

15. Cooke G. Effacing the face: Botox and the anarchivic archive. Body and Society 2008;14:23–38.

16. Park MY, Ahn KY, Jung DS. Botulinum toxin type A treatment for contouring of the lower face. Dermatol Surg 2003; 29:477–483.

17. Carruthers JD, Glogau RG, Blitzer A. Advances in facial rejuvenation: Botulinum toxin type A, hyaluronic acid dermal fillers, and combination therapies—Consensus recommendations. Plast Reconstr Surg 2008;121(5 suppl):5S–30S.

18. Majid O. Clinical use of botulinum toxins in oral and maxillofacial surgery. Int J Oral Maxillofac Surg 2010;39:e197–e207.

19. Johl SS, Burgett RA. Dermal filler agents: A practical review. Curr Opin Ophthalmol 2006;17:471–479.

20. Wang L, Sun Y, Yang W, Lindo P, Singh BR. Type A botulinum neurotoxin complex proteins differentially modulate host response of neuronal cells. Toxicon 2014;82:52–60.

21. Allemann IB, Kaufman J. Fractional photothermolysis—An update. Lasers Med Sci 2010;25:137–144.

22. Dayan SH. Complications from toxins and fillers in the dermatology clinic: Recognition, prevention, and treatment. Facial Plast Surg Clin North Am 2013;21:663–673.

23. Sadick NS, Manhas-Bhutani S, Krueger N. A novel approach to structural facial volume replacement. Aesthet Plast Surg 2013;37:266–276.

24. El-Domyati M, Attia SK, El-Sawy AE, et al. The use of botulinum toxin A injection for facial wrinkles: A histological and immunohistochemical evaluation. J Cosmet Dermatol 2015;14:140–144.

25. Li Y, Hsieh ST, Chien HF, Zhang X, McArthur JC, Griffin JW. Sensory and motor denervation influence epidermal thickness in rat foot glabrous skin. Exp Neurol 1997;147:452–462.

26. American Society of Plastic Surgeons. 2017 Plastic Surgery Statistics Report. https://www.plasticsurgery.org/documents/News/Statistics/2017/plastic-surgery-statistics-report-2017.pdf. Accessed 16 August 2019.

2 /

FACIAL ANATOMY, SKIN BIOLOGY, AND THE EFFECTS OF AGING

Catherine Davies

Richard J. Miron

Understanding facial anatomy is fundamental for any clinician interested in offering esthetic medical procedures. A thorough understanding of skeletal and soft tissue anatomy, facial features and landmarks, and the biology of the skin and hair is required to safely implement the various therapies described in later chapters of this book. The face is comprised of various layers, including the skin, connective tissue, subcutaneous fat, muscles, ligaments, and underlying bone. Within this network, an array of arteries, veins, and nerves also exist. Each layer must be reviewed independently in order to understand the goals and treatment strategies for augmentation of each specific layer and/or tissue type. Minimally invasive injections should avoid damage to key anatomical structures and aim to activate or accelerate wound healing. This chapter reviews the facial anatomy of the face and the biology of the skin and hair and presents an overview of the associated changes to these anatomical structures that occur over time with aging.

Facial Anatomy

Facial Characteristics and Age-Related Changes

The face in general plays a crucial role in society, particularly during social interactions. Facial features are highly relevant to revealing one’s age, mood, and stress level. They are also relevant to facial attractiveness and facial expression, a pivotal language communicator. Younger-looking individuals have plump facial muscles and tight skin with the ability to fully express themselves during facial communication, whereas aging individuals have drooping muscles and loose skin with less facial expression.

Regardless of how beautiful one’s appearance is in their youth, age-related changes and loss of facial volume and features are inevitable. These are often more pronounced and specific to certain areas. A gradual loss of soft tissue occurs in the upper midface region in conjunction with a downward migration of superficial buccal fat. Consequently, the upside-down triangle associated with a youthful look (see Fig 1-1) becomes inverted, with a larger proportion of soft tissue drooping below the midface. While the rate of aging varies among individuals based on genetics, environmental factors, sex, and ethnicity, the following traits are eventually common in all individuals (Fig 2-1):

FIG 2-1

Clinical characteristics of the aging face.

• Drooping of the skin and soft tissues (with loss of subcutaneous fat)

• Wrinkles and creases around the eyes, lips, and forehead

• Changes in skin contour

• Changes in skin pigmentation (eg, dark circles)

• Eyebrow sagging (ptosis)

• Appearance of sunken eyes

• Loss of lip volume

• Irregular chin contour and sagging

Anatomy of the Face

This section of the chapter explores each layer of the face independently so that readers can gain a solid understanding of each before moving on to the next. Each of the images used to illustrate these layers serves as a reference that can be referred to when reading about injection techniques in later chapters. Figure 2-2 depicts common anatomical features of the face that should be standard language for the treating clinician.

FIG 2-2

Landmarks that may be used for facial measurements (lateral view).

Facial skeleton

Figure 2-3 illustrates the various skull bones and their muscle attachment sites.

FIG 2-3

The facial skeleton (left) and muscle attachment sites projected onto it (right).

Muscles of the face

The face consists of 30 different muscles. These are typically divided via three muscle planes and are thus distinguished as (1) superficial, (2) middle, and (3) deep (Fig 2-4). As dynamic coplayers in soft tissue complexes, muscles play an extremely important role in facial aging. Dynamic movements and facial expression require these muscles to contract, and naturally with age, these muscles become hypertrophic, permanently causing visible wrinkles that are involuntary and undesirable.

FIG 2-4

Schematic representation of the facial muscles in three planes: superficial (green), middle (blue), and deep (red).

Subcutaneous fat and connective tissue

The subcutaneous fat in the connective tissue of the face acts as a volumizing cushion for the facial soft tissues. It plays a prominent role in protecting the face from external injury but also ensures a continuous supply of vital fluids and nutrients to facial tissues. The face has a continuous superficial fat compartment (Fig 2-5) and a discontinuous deep fat compartment (Fig 2-6). The superficial compartment is located superior to the superficial fascia of the superficial musculoaponeurotic system (SMAS), while the deep compartment is located beneath the SMAS. Both compartments resemble honeycombs in shape and provide an even, smooth distribution of the skin. Areas with high volume of superficial fat in the face are typically well defined and homogenous in layer. These include the cheeks, nasolabial folds, glabella, and the jaw-chin region (see Fig 2-5). In older patients, this specific tissue decreases with age, with a resulting atrophy typically caused by reduced blood flow. Because there is little superficial fat in the area of the temples and forehead, and almost none in the periorbital and perioral region, these areas are more prone to wrinkles and folds with aging and are one of the first visible signs of facial aging in individuals.

FIG 2-5

Superficial fat distribution in the face.

FIG 2-6

Deep fat compartments of the face.

Figure 2-6 illustrates the deep fat layers. These include the SMAS, retro-orbicularis oculi fat (ROOF), glabellar fat pad, buccal fat pad, and inferior process of the Bichat’s fat pad, among others. These fat pads are larger and, in youthful faces, fully prominent. With aging, atrophy and loss of volume occur, and this again is one of the main visible signs of aging.

Blood supply

A prominent and complex blood vascular network exists throughout the entire region of the face (Fig 2-7). The peripheral skin layers receive their blood supply from fine capillary vessels. These small vessels allow adequate diffusion into all facial layers. When injecting into areas of the face, a thorough understanding of the location of the major blood vessels is crucial. This will avoid potential complications related to intravascular injections, most commonly reported with fillers.

FIG 2-7

Blood vessels of the face projected onto the facial skeleton (left) and the position of the deep arteries and veins of the face relative to the deep muscles (right) (a., artery; aa., arteries; v., vein; vv., veins).

The anatomy of the facial arteries and veins in relation to the muscles of the face is also important to understand (Fig 2-8).

FIG 2-8

Position of the facial arteries and veins relative to that of the moderately deep (left) and superficial (right) muscles (a., artery; v., vein).

Innervation

Along with blood supply to the face, a complex innervation system exists within the face mainly from two sources: the trigeminal nerve and the facial nerve. The sensory innervation of the face is provided by the trigeminal nerve. This nerve is divided into three branches: The V1 ophthalmic nerve exits the orbit via the supraorbital foramen and fissure and supplies sensation to the upper part of the face. The V2 maxillary nerve exits from the infraorbital foramen and innervates the midface. And the V3 mandibular nerve innervates the mandibular and temporal regions (Fig 2-9).

FIG 2-9

Overview of the nerves of the face projected onto the facial skeleton (left) and the position of the deep facial nerves relative to the deep muscles (right) (n., nerve).

The facial nerve, on the other hand, innervates muscles that are involved with facial expression. It divides into five major branches within the parotid gland, and most run superficial to a number of muscles (Fig 2-10). In brief, the temporal branch innervates the temporal, frontal, and palpebral muscles; the zygomatic branch innervates the zygomatic region and lower eyelid muscles; the buccal branch innervates the cheek and periorbital region muscles; the marginal mandibular branch innervates the chin muscles; and the cervical branch innervates the platysma muscles (see Fig 2-10).

FIG 2-10

Position of the facial nerves relative to the moderately deep (left) and superficial (right) muscles (n., nerve).

Biology of the Skin and Hair

Structure and Function of the Skin

As the body’s largest organ, the skin is vital for maintaining human health. While the skin performs many vital functions, its core function is to provide a protective barrier and waterproof sheath for the body. As such, it protects the body’s organs against ultraviolet (UV) light, water loss, microbes, and chemicals. It further assists in temperature regulation and is actively involved in immunologic activities. In addition to executing these vital functions, the skin is also closely related to one’s self-esteem, perception of age, and general well-being. The skin may have a profound impact on social interactions and has been described as playing a key role in esthetics.

The skin is composed of three layers:

1.Epidermis: The epidermis is the outermost layer of the skin and is made up mainly of keratinocytes. The vital barrier function of the skin resides primarily in the top stratum of the epidermis, the stratum corneum. This layer provides a barrier to loss of water from the skin, thus protecting against dehydration, and provides a barrier to irritants of the skin. Melanocytes are the pigment-producing cells of the epidermis and are found at the basal layer. Langerhans cells are scattered in the suprabasal region of the epidermis and provide an important immune barrier.

2.Dermis: The dermis is located beneath the epidermis and is between 1.5 and 4 mm thick. It is the thickest of the three skin layers and makes up approximately 90% of the thickness of the skin. The main functions of the dermis are to supply the epidermis with nutrients, to regulate temperature, and to store much of the body’s water supply. The upper papillary layer has a thin, extensive vascular system that controls the amount of blood flow through the skin. The lower reticular layer is thicker and made of collagen fibers that strengthen the skin, providing structure and elasticity. This layer supports other components of the skin, such as hair follicles, sweat glands, and sebaceous glands.

3.Subcutaneous tissue: Also known as the hypodermis, the subcutaneous tissue is the deepest skin layer and varies in thickness from a few millimeters to several centimeters. It is made of fat, divided by loose connective tissue into fat clusters, and is separated from the underlying tissues by fascia.

Skin Aging

Human skin naturally ages over the course of one’s lifetime as a result of evolutionary imperfection. However, skin is also directly exposed to environmental influences including smoke, UV light, and chemicals, which over the course of a lifetime may drastically speed the aging process. As skin ages, a number of phenotypic and common features may be observed, linked to dryness of skin, wrinkles, and loss of elasticity and/or pigmentation. With advancements made in microscopic imaging, it has become easier than ever to better understand the damage of the skin (caused by UV radiation, chemicals, etc) as seen in changes in collagen and elastic fibers. It is also known that aging causes a reduction in sebaceous and sweat glands typically described as senile xerosis with itching. Hair therefore becomes white and thin, spurring hair loss. Furthermore, aging also causes loosening of the subcutaneous fat layer, which results in a reduction of its thickness and strength and thereby causing a more droopy look. Especially in individuals with lighter skin, the appearance of extrinsic aging tends to be more pronounced and related to atrophy, whereas in darker skin types, a predominant thickening is more commonly observed.

Structural differences in skin also exist between the sexes and among different ethnic groups. In general, under similar climate conditions, the skin of Asian people develops wrinkles on average a decade later when compared to people of central European ancestry. Whereas Europeans typically show a gradual linear change in skin wrinkles and lines, Asians rapidly and dramatically begin to show signs of aging typically between 40 and 50 years of age. However, in everyone, the number of melanocytes typically decreases by 8% to 20% per decade.

While many extrinsic factors play a role in skin aging—including UV exposure, smoking, ionizing radiation, excessive alcohol intake, malnutrition, poor diet, and emotional stress—up to 80% of overall skin damage is caused by direct UV light exposure. This is especially pronounced in lighter skin types. UV light increases the enzymatic activity of matrix metalloproteinases (MMPs), proteins known to be responsible for the degradation of collagen. Furthermore, UV light increases the amount of reactive oxygen species (ROS) in cells, which leads to DNA damage and increased chance for neoplasms. During such prolonged activity, the body accumulates ROS and the detox system is often overloaded. Antioxidants, such as vitamin C, have since been applied topically and have been shown to play a role in minimizing skin aging.

Intrinsic (genetic) factors also play a key role in aging. Typically, thinning of the skin occurs between the 3rd and 8th decades of life, generally accompanied by marked hypocellularity. This leads to a 10% to 50% reduction in skin thickness. Clinically this presents as loosening of the skin and a reduction in subcutaneous fat layers. A dramatic reduction in vascularity of skin tissues is also observed with aging and may be a primary link to the histologic observation of hypocellularity and reduction in skin thickness. The concept of utilizing a concentration of growth factors derived from blood (platelet concentrates) has therefore been proposed as a means to reverse or slow down the aging process, as discussed later in this textbook.

Structure and Function of the Hair

The average human scalp contains between 90,000 and 140,000 terminal hairs. These hairs can grow approximately 1 cm per month. Meanwhile, hair loss is continuous, with people losing about 100 hairs per day on average.

The pilosebaceous or hair follicle unit is made up of the hair follicle along with an attached sebaceous gland and arrector pili muscle. Hair follicles vary considerably in size and shape, depending on their location, but they all have the same basic structure. The number and distribution of hair follicles over the body and the future phenotype of each hair is established during fetal development; no additional follicles are added after birth.

The hair follicle begins at the surface of the epidermis and extends into the dermis. Vellus hairs may extend only into the reticular dermis, whereas terminal hairs extend deeper, sometimes even into the subcutis (Fig 2-11).

FIG 2-11

Representative image of a hair follicle. Injection techniques with platelet concentrates aim for the bulb of the hair follicle, located between 1.5 and 4 mm below the surface of the scalp.

Hair zones

Each follicle can be divided into distinct regions: the bulb, suprabulbar zone, isthmus, and infundibulum. The infundibulum begins at the surface of the epidermis and extends to the opening of the sebaceous duct. The isthmus is the area between the sebaceous duct opening and the bulge. The bulge is an area of the follicle marked by the insertion of the arrector pili muscle. The bulge contains several epidermal stem cells that are part of the outer root sheath and may be a target for hair loss treatments.

The bulge contains several epidermal stem cells that are part of the outer root sheath and may be a target for hair loss treatments.

The suprabulbar zone extends from the bulge to the top of the bulb. The hair bulb sits between 1.5 and 4 mm deep.The bulb contains matrix cells that proliferate regularly. These cells surround the sides and top of the dermal papilla and are responsible for the production of the hair shaft as well as the inner and outer root sheaths. The dermal papilla contains capillaries and interacts with the matrix cells in the hair bulb.

Melanocytes among the matrix cells provide the hair with its individual color. Hair color is determined by the distribution of melanosomes in the hair shaft. The hair bulb contains melanocytes that synthesize melanosomes and transfer them to the keratinocytes of the bulb matrix. Aging causes a loss of melanocytes and a corresponding decrease in the production of melanosomes, resulting in graying hair.

Hair layers

The hair shaft consists of an inner core known as the medulla. This is surrounded by the cortex, which makes up the bulk of the hair. Moving outward, there is a single layer of cells making up the shaft cuticle. The shaft cuticle is then encased in three layers that form the inner (internal) root sheath. The inner sheath is important in shaping the hair shaft as it grows upward from the matrix. The inner sheath keratinizes from the outside in and will eventually disintegrate midfollicle around the level of the isthmus. Finally, the outer (external) root sheath encases the entirety of the hair shaft. This layer undergoes trichilemmal keratinization around the level of the isthmus.

Sebaceous glands are acinar holocrine-secreting appendages of the epidermis and are a crucial component of the pilosebaceous unit. They are found all over the body, especially in certain areas of the skin such as the face. These glands open onto the hair follicles, except in areas such as the lips, where they empty directly onto the mucosa surface because lips do not contain hair follicles. When stimulated by hormones such as androgens, sebaceous glands produce and release sebum, an oily and waxy material. This contributes to the hydrophobic barrier of the skin.

The arrector pili muscle is a small band of smooth muscle bundle that attaches to the external root sheath of the bulge region of the follicle and extends to its superior attachment in the upper dermis. It is innervated by the sympathetic branch of the autonomic nervous system. In cold climates, sympathetic stimulation causes these muscles to contract. This raises the level of the skin slightly and causes the hair to stand erect, which is commonly referred to as “goosebumps.”

The hair growth cycle

Hair growth occurs in a cyclical manner, but each follicle follows its own hair cycling schedule, completely independent of other hairs on the scalp. A normal hair growth cycle has three phases: anagen, catagen, and telogen (Fig 2-12).

FIG 2-12

Hair growth cycle.

The anagen phase is the active growth stage and typically lasts approximately 2 to 7 years on the scalp. Approximately 85% to 90% of hair is in the anagen phase at any given time.

The catagen phase, also known as the transition phase, lasts about 2 weeks and is a period of involution resulting in club hair formation after many cells in the outer root sheath undergo apoptosis. The club hair has a white, hard node on the end.

The telogen phase is also known as the resting phase. Club hairs, which are essentially dead, are held on the scalp. They are typically held for about 100 days and then released and shed so that the anagen phase can begin again with a new hair.

Other sites on the body tend to have shorter anagen and longer telogen phases, causing most body hair to be shorter and remain in place for longer periods of time.

Hair loss and the growth cycle

When hair loss occurs, regardless of the cause, the hair growth cycle is almost always affected. An abnormal or disrupted hair growth cycle can occur at any phase:

•Shortened anagen phase: The duration of the growth phase is shortened, and the entire hair growth cycle becomes affected.

•Early catagen phase: