v

Contents

Foreword ixIntroduction xiContributors xvDedication xix

1 Phonatory Anatomy 1Introduction 1Classic Articles 2Commentary by Minoru Hirano 3“Morphological structure of the vocal cord as a vibrator and its variations” 5

by M. HiranoCommentary by Ira Sanders 11“The innervation of the human larynx” 15

by I. Sanders, B.L. Wu, L. Mu, Y. Li, H.F. BillerCommentary by Uwe Jürgens 21“Neural pathways underlying vocal control” 23

by U. Jürgens

2 Perception of Voice 47Introduction 47Classic Articles 47Commentary by Jody Kreiman and Bruce R. Gerratt 48“Perceptual evaluation of voice quality: review, tutorial, and a framework for future research” 52

by J. Kreiman, B.R. Gerratt, G.B. Kempster, A. Erman, G.S. Berke“Test-retest study of the GRBAS scale: influence of experience and professional background 72on perceptual rating of voice quality”

by M.S. DeBodt, F.L. Wuyts, P.H. Van de Heyning, C. Croux

3 Description and Quantification of Voice Production 79Introduction 79Classic Articles 79Commentary by Thomas J. Hixon and Judith R. Smitheran 81“A clinical method for estimating laryngeal airway resistance during vowel production” 84

by J.R. Smitheran and T.J. HixonCommentary by Douglas M. Hicks 93“Acoustic correlates of vocal quality” 96

by D.M. Hicks, L. Eskenari, D.G. Childers“Changes in phonation threshold pressure with induced conditions of hydration” 105

by K. Verdolini-Marston, I.R. Titze, D.G. DrukerCommentary by James M. Hillenbrand 115

“Acoustic correlates of breathy vocal quality” 117by J.M. Hillenbrand, R.A. Cleveland, R.L. Erickson

4 Clinical Voice Disorders and Voice Therapy 127Introduction 127Classic Articles 127Commentary by Murray Morrison 129“Muscle misuse voice disorders: description and classification” 130

by M.D. Morrison and L.A. RammageCommentary by Lorraine O. Ramig 137“Comparison of two forms of intensive speech treatment for Parkinson disease” 144

by L.O. Ramig, S. Countryman, L.L. Thompson, Y. Horii“Frequency and effects of teachers’ voice problems” 164

by E. Smith, S.D. Gray, H. Dove, L. Kirchner, H. Heras

5 Laryngopharyngeal Reflux and Its Sequelae 171Introduction 171Classic Articles 172Commentary by Jerrie Cherry 174“Contact ulcer of the larynx” 175

by J. Cherry and S. MarguliesCommentary by Jamie Koufman 179“The otolaryngologic manifestations of gastroesophageal reflux disease (GERD): a clinical 189investigation of 225 patients using ambulatory 24-hour pH monitoring and an experimentalinvestigation of the role of acid and pepsin in the development of laryngeal injury”

by J.A. KoufmanCommentary by Robert J. Toohill 267“Role of refluxed acid in pathogenesis of laryngeal disorders” 270

by R.J. Toohill and J.C. Kuhn“Laryngopharyngeal reflux: position statement of the Committee on Speech, Voice, 277 and Swallowing Disorders of the American Academy of Otolaryngology-Head and Neck Surgery”

by J.A. Koufman, J.E. Aviv, R.R. Casiano, G.Y. Shaw

6 Endoscopic Laryngeal Surgery 281Introduction 281Classic Articles 281Commentary by M. Stuart Strong 282“Laser surgery in the larynx. Early clinical experience with continuous CO2 laser” 284

by S.M. Strong and G.J. Jako

7 Benign Laryngeal Lesions 293Introduction 293Classic Articles 293“Cysts of the larynx—classification” 294

by L.W. DeSanto, K.D. Devine, L.H. WeilandCommentary by Susan L. Thibeault 326“Benign pathologic responses of the larynx” 328

by S.D. Gray, E. Hammond, D.F. Hanson

vi CLASSICS IN VOICE AND LARYNGOLOGY

8 Laryngeal Scarring and Stenosis 335Introduction 335Classic Articles 335Commentary by Michael S. Benninger 336“Vocal fold scarring: current concepts and management” 338

by M.S. Benninger, D. Alessi, S. Archer, R. Bastian, C. Ford, J. Koufman, R.T. Sataloff, J.R. SpiegelCommentary by Stanley M. Shapshay 347“Mitomycin: effects on laryngeal and tracheal stenosis, benefits, and complications” 351

by R. Rahbar, S.M. Shapshay, G.B. Healy

9 Recurrent Respiratory Papillomatosis 357Introduction 357Classic Articles 357Commentary by Bettie M. Steinberg 359“Laryngeal papillomavirus infection during clinical remission” 362

by B.M. Steinberg, W.C. Topp, P.S. Schneider, A.L. Abramson“Intralesional cidofovir for recurrent respiratory papillomatosis in children” 366

by S.M. Pransky, A.E. Magit, D.B. Kearns, D.R. Kang, N.O. DuncanCommentary by Craig S. Derkay 372“Recurrent respiratory papillomatosis” 373

by C.S. Derkay

10 Laryngeal Malignancy and Vocal Outcomes 387Introduction 387Classic Articles 387Commentary by W. Frederick McGuirt, Sr. 389“Comparative voice results after laser resection or irradiation of T1 vocal cord carcinoma” 392

by W.F. McGuirt, D. Blalock, J.A. Koufman, R.S. Feehs, A.J. Hillard, K. Greven, M. RandallCommentary by Steven M. Zeitels 397“Premalignant epithelium and microinvasive cancer of the vocal fold: the evolution of 402phonomicrosurgical management”

by S.M. Zeitels

11 Vocal Fold Paralysis 453Introduction 453Classic Articles 454“Etiology of bilateral abductor vocal cord paralysis. A review of 389 cases” 455

by L.D. Holinger, P.C. Holinger, P.H. HolingerCommentary by Gayle E. Woodson 464“Configuration of the glottis in laryngeal paralysis. I: clinical study” 467

by G.E. WoodsonCommentary by Roger L. Crumley 475“Evaluation and treatment of the unilateral paralyzed vocal fold” 480

by M.S. Benninger, R.L. Crumley, C.N. Ford, W.J. Gould, D.G. Hanson, R.H. Ossoff, R.T. Sataloff

12 Vocal Fold Augmentation 493Introduction 493Classic Articles 494Commentary by Charles N. Ford 495

CONTENTS vii

“Role of injectable collagen in the treatment of glottic insufficiency: a study of 119 patients” 498by C.N. Ford, D.M. Bless, J.M. Loftus

Commentary by Gary Y. Shaw 509“Autologous fat injection into the vocal folds: technical considerations and 511long-term follow-up”

by G.Y. Shaw, M.A. Szewczyk, J. Searle, J.Woodroof“Viscosities of implantable biomaterials in vocal fold augmentation surgery” 521

by R.W. Chan and I.R. Titze

13 Laryngeal Framework Surgery 529Introduction 529Classic Articles 530Commentary by Nobuhiko Isshiki 531“Thyroplasty as a new phonosurgical technique” 534

by N. Isshiki, H. Morita, H. Okamura, M. Hiramoto“Arytenoid Adduction for Unilateral Vocal Cord Paralysis” 541

by N. Isshiki, M. Tanabe, M. Sawada“Silastic medialization and arytenoid adduction: the Vanderbilt experience. A review of 545116 phonosurgical procedures”

by J.L. Netterville, R.E. Stone, E.S. Luken, F.J. Civantos, R.H. Ossoff

14 Laryngeal Dystonia 557Introduction 557Classic Articles 558Commentary by Herbert H. Dedo 559“Recurrent laryngeal nerve section for spastic dysphonia” 562

by H.H. DedoCommentary by Andrew Blitzer 571“Laryngeal dystonia: a series with botulinum toxin therapy” 574

by A. Blitzer and M.F. Brin

15 Laryngeal Transplant 579Introduction 579Classic Articles 579Commentary by Marshall Strome 580“Laryngeal transplantation and 40-month follow-up” 582

by M. Strome, J. Stein, R. Esclamado, D. Hicks, R.R. Lorenz, W. Braun, R. Yetman, I. Eliachar, J. Mayes

viii CLASSICS IN VOICE AND LARYNGOLOGY

Neither the concept for this volume, nor the term “clas-sic” in the context of science is novel. In 1977, EugeneGarfield’s essay entitled, “Introducing Citation Classics:The human side of scientific papers” was the first to rec-ognize highly-cited manuscripts and their contributionto science (Garfield, 1977). In this essay, published inCurrent Contents, Garfield described his vision for rec-ognizing those investigators who made significant con-tributions to science in general. In addition, Garfieldcompiled a list of the 500 most-cited manuscripts pub-lished between 1961 and 1975, including Oliver H.Lowry’s 1951 paper on protein quantification, the most-cited in the history of science (Lowry et al., 1951).Although the list is interesting, a significant part of theappeal of Garfield’s effort was his idea to solicit com-mentaries from the authors of these landmark papers.Dr. Garfield requested that authors provide insight into“interesting aspects in the development of their tech-niques, the role played by coauthors or others, and theencouragement received from colleagues.” Commentar-ies included personal anecdotes regarding the scientificprocess, obstacles encountered, and often, the author’sinsight into why their paper has been cited so frequently.Garfield’s approach in Citation Classics was insightfuland fundamentally humanistic, bringing out the per-sonalities behind the affectless, impersonal authorialvoice typical of scientific papers. In so doing, he explic-itly recognized that these seminal contributions to sci-ence were made by individuals, encouraged, inspired,constrained, or thwarted by their training, colleagues,mentors, and environment.

With great admiration for Garfield’s work and theprecedent he set, we present Classics in Voice and Laryn-gology. We recognize that laryngology and voice sciencerepresent a small niche within otolaryngology. As such,it is unlikely that seminal works in the advancement of this field will ever be recognized in the context of science, in general. However, many publications havesignificantly altered the way voice production is con-ceptualized and changed treatment for patients with

voice disorders. In fact, in the period covered by thiscompilation (1967 to 2007), laryngology and voice sciencehave undergone tremendous expansion and change.One recoils from the phrase “paradigm shift,” which isused incontinently these days. Yet it obviously andinescapably applies. Laryngology was one of the firstmedical specialties, brought to life by the developmentof the laryngeal mirror. Its early practitioners werereviled and not infrequently expelled by the generalmedical establishment, which found specialization abhor-rent. Not only was laryngology an early specialty, but itestablished the whole concept of specialization in med-icine. Then it fell on hard times. The mastery of infec-tious disease, especially tuberculosis and syphilis, overa very few decades shrank the nonmalignant caseload,and the field atrophied. For a long period, all that wasleft to it was laryngeal cancer, and it became a minorsubdiscipline of head and neck surgery. Its renaissancehas been due to the development of surgical endoscopyand microscopic surgical visualization, the resurgenceand refinement of framework surgery, stroboscopy, anddramatic and fundamental insights into anatomy andphysiology—in fact, by the very authors and papershonored in this volume.

The goals of Classics in Voice and Laryngology arethree-fold: (1) to recognize great contributions and con-tributors to the field, (2) to set down in writing aspects ofthe evolution of voice science and medicine that mightfade with time or never be known, and (3) to provide acompilation of landmark manuscripts for both currentand future clinician-scientists. As did Garfield, we feelthat the author commentaries prepared especially for thisvolume are as valuable as the papers themselves.

We owe a debt of gratitude to the many leaders inthe field that participated in this project. Originally, wehoped to include commentaries from the authors ofevery manuscript included as a Classic. This provedimpossible for many reasons. Instead, we attempted toacquire commentaries from a spectrum of investigators,hopefully representing the broad number of research

xi

Introduction

interests encompassed within voice and laryngology.Undoubtedly, we omitted commentaries from manyleaders, for which we sincerely apologize and ask forunderstanding.

What is a Classic?

Although we recognize that pure objectivity is not pos-sible, we tried to develop a rigorous, yet simple formulato determine which articles to include. The number ofcitations required to be labeled a classic in various fieldsis highly variable. In botany, for example, 100 citationsare required. However, in larger fields such as molecu-lar biology, 500 citations may be required. Recognizingthat voice and laryngology represent extremely smallfields, the number of relevant citations was set, afterconsultation with leaders in the field and a review of theresults of various thresholds, at 50. On one hand, wesought to identify truly significant papers, but also coverthe compass of the field, something not well achieved athigher cutoff points. For instance, had the number ofcitations required for inclusion increased to 100, virtu-ally the entire volume would have been composed ofpapers on laryngopharyngeal reflux, which is evidentlythe most hotly-discussed topic in the voice literature inthe past 40 years. Even at 50, some omissions, detailedbelow, gave us pause. But the number of papers hadgrown such that we did not dare to expand the field.

A classic, therefore, is defined as a scholarly manu-script in the fields of laryngology, vocology, and/orvoice science that has been cited in other work morethan fifty times. The program Scopus® was employed todetermine manuscript eligibility for the title of Classic.Using Scopus®, the following key words were used togenerate a list of all articles published between 1967 and2007: voice, voice disorder, dysphonia, larynx, vocalfold, and vocal cord. Acknowledging that keywords arenot included in some scholarly publications, we thenundertook a review of the references from the selectedarticles in addition to an author name search. For exam-ple, the most highly-cited manuscript included in thistext, Dr. Koufman’s paper on the otolaryngologic mani-festations of gastroesophageal reflux disease, does notinclude keywords, and would therefore have been omit-ted by simply utilizing Scopus® alone.

We debated whether to include review articles,position papers, and the like. The argument against isobvious: these are not original contributions. The argu-

ment in favor rests solely on their import. In the end, wedecided these merited a place; as a distillation of thestandard of care, the state of the art, what have you, ata particular point in time, these are undoubtedly influ-ential and serve as significant and explicit points of ref-erence for practitioners and investigators.

Once the list of Classics was compiled, we thenattempted to categorize the articles according to topic.This process led us to the development of 15 imperfectand occasionally overlapping areas of voice and laryn-gology. Although most articles fit nicely into one cate-gory, in some cases it seemed as though we were tryingto fit a square peg into a round hole.

Originally, we wished to reprint all of the articlesthat met the criteria of a Classic. We quickly altered thatplan, as the size of such a book was obviously not fea-sible, and chose to present selected papers only. Herewe used editorial judgment, for which we accept fullresponsibility, guided by a few principles and externalconstraints. Where there were multiple related publica-tions for the same investigative group, we chose whatseemed to be the broadest and most representative pub-lication. Almost always, our choice was validated by thecitation count, higher for our selection than that of othersimilar papers. Elsewhere, the choice was more chal-lenging. We preserved our preference for overviews of aninvestigator or investigating group’s work where possi-ble. We also gave preference, where possible, to worksby authors who agreed to provide commentaries. It isworth mentioning that not everyone that we approachedagreed to do so. We do not attempt to present explica-tions of their reasons here. Throughout the entire task of electing articles to include in toto, we preserved ourrespect and consideration for the citation counts asobjective markers of significance.

We were subject to the significant limitation thatcertain journals demanded exorbitant fees for reproduc-tion, amounting to four figure sums for single articlesthat effectively excluded articles published between theircovers from this volume. We do not hesitate to say thatwe find this to be an injustice to their authors, incom-patible with the mission of an academic journal, andalso just plain shortsighted.

What’s Missing?

We understand that the method cannot be perfect, andmay not be entirely just. Some of this is by design. For

xii CLASSICS IN VOICE AND LARYNGOLOGY

instance, we excluded a few articles that came up in oursearch that did not specifically address voice, such aspapers on laryngeal cancer that did not concern them-selves with voice outcomes. More is by accident. Paperspublished without abstracts or keywords, like the NewEngland Journal of Medicine description of the first laryn-geal transplantation, did not register on any of oursearches, and were discovered on an incidental cross-check. We performed such crosschecks for many paperswhose omission seemed surprising to us. We hasten toadd that neither our surprise nor our estimation weresufficient by themselves to include an article; every onehad to meet the citation count. Our ignorance, on theother hand, may have by itself resulted in unfair exclu-sions. Again, we apologize.

We noted with dismay, but no particular shock, thatnone of our own papers made the cut. However, we areable to guarantee that these omissions at least are notdue to any lack of checking.

By definition, the roster generated for this project isdynamic–the body of classics is constantly shifting bysmall increments. As time goes on, new publications citetheir predecessors, and more papers make the grade.Anyone who wishes to repeat this project in a few yearswill find either that the resulting volume must be thickeror that the benchmark number of citations will have tochange. As a corollary, it takes some maturity and sea-soning to be included. Recent developments, such asthe angiolytic lasers, at the forefront of discourse now,are invisible in this work. Time will decide whether theyare passing fashions or . . . well, classics.

The omission of some topics was puzzling. Micro-laryngoscopic surgery—bimanual, magnified endo-scopic surgery which takes into account the micro-anatomic details revealed in recent years—is verypoorly represented, for instance. On reflection, though,it becomes clear, no matter how seminal Kleinsasser’sbook Microlaryngoscopy and Endolaryngeal Microsurgery,that these techniques are very poorly represented in thepeer-reviewed literature. There are case series justifyingits use in various patient groups, papers quibbling overmini-, micro-, and probably nanoflaps, and pieces intro-ducing various pieces of equipment, but none of these are widely cited. Is this because the justification of thetechnique rests elsewhere, specifically in the paper byHirano and Sato included in this volume, or because, aswe would like to think, the superiority of microlaryn-goscopy is so self-evident that it has become the stan-dard of treatment virtually without debate?

Along a similar thread, there are no single reportsregarding the efficacy of voice therapy techniques withthe exception of Dr. Ramig’s LSVT. Given the recentproliferation of high-level behavioral intervention, it istroubling that the literature is essential void of goodquality efficacy data. It is also interesting that, in theabsence of a single efficacy study, Drs. Ramig and Ver-dolini provide a comprehensive review of the efficacydata, a true classic manuscript. We hypothesize twopotential explanations for this finding. The first is that,until only recently, translational research was unheardof. Communication and collaboration between the ivorytower and the clinic was rare. Looking at the authors onthe current list of classics, you can sense the tide ofchange. Secondly, and perhaps a more persistent issue,is the lack of fundamental metrics by which therapeuticsuccess is determined. The list of classics is relativelysparse on the identification of clinically-viable measuresby which to directly or indirectly quantify voice produc-tion and the potential for change related to intervention.The reasons are left for another forum; for now, we notethe omission.

Obtaining and Assembling Manuscripts

Once the list of articles was compiled and the articleswere placed, sometimes awkwardly, into categories, webegan the tedious and sometimes disappointing task ofobtaining permissions. We wish to acknowledge themany journals and publishers who supported this proj-ect and provided permissions for either no charge or fora reasonable rate. A list of these supportive journals andpublishing houses is provided below. There are obviousomissions from this list. It is unfortunate that some didnot share our vision to recognize those individuals whohave shaped our field.

Acta OtolaryngolicaTaylor and Francis Group

Annals of Otology, Rhinology, and LaryngologyAnnals Publishing Group

Archives of Otolaryngology-Head and NeckSurgeryAmerican Medical Association

Folia PhoniatriciaKarger Publishing

INTRODUCTION xiii

Journal of Speech, Language and HearingResearchJournal of Speech and Hearing ResearchAmerican Speech, Language, and HearingAssociation

LaryngoscopeLippincott, Williams, & Wilkins

New England Journal of MedicineMassachusetts Medical Society

Journal of VoiceOtolaryngology-Head and Neck SurgeryAmerican Journal of MedicineNeuroscience and Biobehavioral ReviewsElsevier Ltd.

We also wish to thank those individuals who sawmerit in the concept of Classics for our field and sup-ported it in various ways. Robert T. Sataloff, MD DMA,in his capacity of Editor-in-Chief of Journal of Voice andsenior statesman in laryngology, intervened with thepublisher of several journals to break an impasse inreproduction rights and fees. Tom Murry, PhD providedadvice and guidance, and in many respects served asgodparent to the project. Last, but in many respects mostimportant, we wish to thank the Singhs and their teamat Plural Publishing for their support and encourage-ment of our vision.

Classics and the Future

As we write, laryngology is gelling into a solid, well-recognized subspecialty in which the clinical and thebasic sciences are in communication and in synch to agreater degree than in most other fields of medicine.Various intellectual threads, all represented betweenthese covers, have joined over the past few decades toform an integrated cloth of investigation and patientcare. We are excited to be part of it and have found a res-onance for our enthusiasm in the many contributorswith whom we have interacted in this project. We hopethat Classics in Voice and Laryngology conveys not onlythe substance of their contribution, but also some of theintellectual curiosity, process and excitement that hascreated the momentum that we are benefiting fromtoday. It is certainly a reminder of how far we havecome in a very short time, and we hope a touchstoneand inspiration for continued advances for the benefitof our patients.

References

1. Garfield E. Introducing citation classics: the humanside of scientific reports. Current Contents. 1977;3:1–2.

2. Lowry OH, Rosenbrough NJ, Farr AL, Randall RJ. Pro-tein measurement with the Folin phenol reagent. J BiolChem. 1951;193:265–275.

xiv CLASSICS IN VOICE AND LARYNGOLOGY

Michael S. Benninger, MDChairman, Head and Neck Institute, The Cleveland

ClinicProfessor of Surgery, The Lerner School of Medicine

of Case Western Reserve UniversityCleveland, OhioChapter 8

Andrew Blitzer, MD, DDS, FACSProfessor of Clinical OtolaryngologyCollege of Physicians and Surgeons of Columbia

UniversityDirector, New York Center for Voice and

Swallowing DisordersNew York, New YorkChapter 14

Ryan C. Branski, PhDAssistant Attending ScientistHead and Neck SurgeryMemorial Sloan-Kettering Cancer CenterAssistant Professor of OtorhinolaryngologyWeill Cornell Medical CollegeNew York, New YorkIntroduction

Jerrie Cherry, MDRetiredChapter 5

Roger L. Crumley, MDProfessor and Chairman-EmeritusDept of Otolaryngology—Head and Neck SurgeryDirector, University Voice and Swallowing CenterUniversity of California, IrvineIrvine, CaliforniaChapter 11

Herbert H. Dedo, MDProfessor of OtolaryngologyUniversity of California, San FranciscoSan Francisco, CaliforniaChapter 14

Craig S. Derkay, MD, FAAP, FACSProfessor and Vice-Chairman, Department of

Otoloaryngology and PediatricsEastern Virginia Medical SchoolDirector, Pediatric Otolaryngology, Children’s

Hospital of the King’s DaughtersNorfolk, VirginiaChapter 9

Charles N. Ford, MD, FACSProfessor, Department of Surgery, Division of

OtolaryngologyUniversity of WisconsinSchool of Medicine and Public HealthMadison, WisconsinChapter 12

Bruce Gerratt, PhDProfessorDivision of Head and Neck SurgeryUniversity of California, Los AngelesLos Angeles, CaliforniaChapter 2

Douglas M. Hicks, PhD, CCC-SLPDirector, The Voice CenterHead, Speech-Language PathologyCleveland ClinicCleveland, OhioChapter 3

James M. Hillenbrand, PhDDepartment of Speech Pathology and AudiologyWestern Michigan UniversityKalamazoo, MichiganChapter 3

Minoru Hirano, MD, PhD, FACS (Hon)Chancellor Emeritus and Professor EmeritusKurume UniversityKurume, JapanChapter 1

xv

Contributors

Thomas J. Hixon, PhD, CCC-SLPProfessor EmeritusDean EmeritusUniversity of ArizonaTucson, ArizonaChapter 3

Nobuhiko Isshiki, MD, PhDHead of Isshiki Clinic, KYOTO Voice Surgery CenterEmeritus Professor at Kyoto UniversityKyoto, JapanChapter 13

Uwe Jürgens, Dr.rer.nat.Professor EmeritusGöttingen, GermanyUniversity of GöttingenChapter 1

Jamie Koufman, MDDirector, Voice Institute of New YorkProfessor of Clinical OtolaryngologyNew York Medical CenterNew York Eye and Ear InfirmaryNew York, New YorkChapter 5

Jody Kreiman, PhDProfessor of SurgeryDivision of Head and Neck SurgeryUniversity of California, Los AngelesLos Angeles, CaliforniaChapter 2

W. Frederick McGuirt, MD, FACSJames A. Hanil Professor Emeritus, Wake ForestUniversity and N.C. Baptist HospitalDepartment Chair OtolaryngologyHefner Veterans Administration Hospital, Active

FacultyWake Forest, North CarolinaChapter 10

Murray D. Morrison, MD, FCRS (C)Professor Emeritus of Surgery (Otolaryngology)University of British ColumbiaDirector, Pacific Voice Clinic Inc.Vancouver, British Columbia, CanadaChapter 4

Lorraine Ramig, PhD, CCC-SLPUniversity of Colorado—BoulderNational Center for Voice and Speech, DenverColumbia University, Teachers College, New York

CityBoulder, ColoradoChapter 4

Ira Sanders, MDChapter 1

Robert T. Sataloff, MD, DMA, FACSProfessor and Chairman, Dept. of Otolaryngology—

Head and Neck SurgeryAssociate Dean for Clinical Academic SpecialtiesDrexel University College of MedicineChairman, The Voice FoundationPhiladelphia, PennsylvaniaForeword

Stanley M. Shapshay, MDProfessorDivision Otolaryngology—Head and Neck

SurgeryAlbany Medical CollegeAlbany, New YorkChapter 8

Gary Y. Shaw, MD, FACSClinical Professor of Surgery, Kansas City University

of Medicine and Biomedical StudiesPresident, Voice and Swallowing Cure

FoundationKansas City, KansasChapter 12

Judith R. Smitheran, MS, CCC-SLPSpeech/Language PathologistSt. Vincent Regional Medical Center, Santa Fe,

New MexicoSanta Fe, New MexicoChapter 3

Bettie M. Steinberg, PhDProfessorChief Scientific Officer, The Feinstein Institute for

Medical Research, andDean, Elmezzi Graduate School of Molecular

Medicine

xvi CLASSICS IN VOICE AND LARYNGOLOGY

North Shore—LIJ Health SystemManhasset, New YorkChief, Otolaryngology ResearchLong Island Jewish Medical CenterNew Hyde Park, New YorkChapter 9

Marshall Strome, MD, MS, FACSDirector, Center for Head and Neck

OnocologyCo-Director, Head and Neck Transplantation

ProgramNew York Head and Neck InstituteNew York, New YorkChapter 15

M. Stuart Strong, MDProfessor Emeritus, Otolaryngology/Head and

Neck SurgeryBoston UniversitySchool of MedicineBoston, MassachusettsChapter 6

Lucian Sulica, MDDirector, Voice Disorders/LaryngologyAssociate Professor of OtorhinolaryngologyWeill Cornell Medical CollegeNew York, New YorkIntroduction

Susan L. Thibeault, PhDAssistant ProfessorDivision of Otolaryngology—Head and Neck SurgeryDepartment of SurgeryUniversity of Wisconsin-MadisonMadison, WisconsinChapter 7

Robert J. Toohill, MD, FACSProfessor of Otolaryngology and Communication

SciencesThe Medical College of WisconsinMilwaukee, WisconsinChapter 5

Gayle E. Woodson, MDProfessor and ChairDivision of Otolaryngology—Head and Neck SurgerySIU School of MedicineSpringfield, IllinoisChapter 11

Steven M. Zeitels, MD, FACSEugene B. Casey Professor of Laryngeal SurgeryHarvard Medical SchoolDirector: Center for Laryngeal Surgery and Voice

Rehabilitation,Massachusetts General HospitalBoston, MassachusettsChapter 10

CONTRIBUTORS xvii

PHONATORY ANATOMY 3

Commentary

Minoru Hirano, MD, PhD, FACS (Hon)

The original paper1 was submitted for publication in1973 and published in 1974. Our studies on the struc-ture and vibration of the vocal fold continued until theend of 1996 when the author retired from his chair asProfessor of Otolaryngology. This commentary presentsour most recent study results and models.

Morphological Structure of the Human Vocal Fold

The vocal fold comprises the vocalis muscle and mucosa.The mucosa, in turn, is made up of the epithelium andlamina propria. The lamina propria consists of superfi-cial, intermediate and deep layer.

The superficial layer of the lamina propria (Lps),referred to as Reinke’s space, is composed chiefly of an amorphous substance and is loose and pliable. Theintermediate layer (Lpi) is primarily consists of elasticfibers and the deep layer (Lpd), collagenous fibers. Lpsis clearly delineated from Lpi. The border between Lpiand Lpd is not distinct. They together form the vocalligament. The fibers of Lpd go into the vocalis muscle.Around the edge of the vocal fold, the elastic and colla-gen fibers in the vocal ligament, as well as the muscle

fibers in the vocalis muscle, run roughly parallel to theedge, facilitating vibratory movements.

The findings mentioned above indicate that the vocalfold should be regarded as, at least, a double-layeredvibrator consisting of a body made up of the vocalismuscle and the vocal ligament, and the cover consistingof the epithelium and Lps.

Physiological Variations

The mechanical properties of the vocal fold, such asposition, shape, mass, tension, and elastic constant, aredetermined by the intrinsic and extrinsic laryngeal mus-cles. Among these muscles, the most important in deter-mining the relationship between the body and the coverof the vocal fold are the vocalis and the cricothyroidmuscles.

Four typical laryngeal adjustments in terms of therelationship between the body and the cover are pro-posed in Figure 2 of the reprinted work, which presentsschematically frontal sections of the vocal fold duringvibration. The vocal fold is deformed to a great extentfrom the rest state. The first three, Figures 2a, 2b, and 2c,represent condition of heavy or modal register, which is

associated with a more or less marked wavelike move-ment of the mucosa, or mucosal wave, having up-and-down movements. Two ripples in these pictures presentthe so-called upper and lower lips, respectively.

In Figire 2a, contraction of both the vocalis andcricothyroid muscles is very weak. This occurs in softphonation at low pitch levels. The elastic constant ofboth the body and the cover is small because there is lit-tle tension in or on the vocal fold. Both the body and thecover are very flexible, and are almost equally involvedin the deformation.

In Figure 2b, the vocalis muscle contracts much morepowerfully than the cricothyroid. This happens in loudheavy voice at medium pitch levels. The body is stiffand has a high elastic constant. The cover is slackenedand associated with a small elastic constant. Deformationduring vibration occurs mainly in the cover, especiallythe wavelike movement involves only the cover.

Figure 2c represents a group of conditions wherecontraction of the vocalis muscle is a little more domi-nant than that of the cricothyroid, that is, conditionsbetween Figures 2a and 2b. This is supposedly the casewith most phonation in heavy or modal register. Defor-mation of the vocal fold, especially the wavelike move-ment, involves both the body and the cover, but moremarkedly the cover.

Figure 2d represents conditions for light register orfalsetto. The vocals muscle is not active or only slightlyactive, whereas the cricothyroid contracts powerfully.Both the body and the cover are passively stretched andmade tense. Both are associated with a high elasticityconstant. In this condition, changes in shape duringvibration are smaller than in modal register, and thewavelike movement does not appear.

Needless to say, the expiratory force is one of the mostimportant factors which determine the mode of changesin the vocal fold shape during vibration. Figure 2 showsconditions where the expiratory force is at its optimum.

Pathological Variations

Several pathologic conditions are associated with typi-cal changes in mechanical properties of the vocal fold.The changes, in turn, are reflected as variations in themode of vibration. A slight or moderate degree of edemain Lps results in a decrease in the elastic constant of the cover. This is recognized as a pronounced wavelike

movement under a stroboscopic light or in an ultra-high-speed film. The deformation of the vocal fold dur-ing vibration seems to involve the cover to a greaterextent than the body.

A carcinomatous lesion of the vocal fold, which isfirst developed in the cover and invades the body later,causes an increase in the elastic constant of the tissue.This usually results in immobility of the affected por-tion during phonation. A similar state is also caused bypapilloma or hyperkeratosis. It is usually developedfrom the epithelial layer of the cover.

In recurrent laryngeal nerve paralysis, the vocalismuscle does not contract. Because the cricothyroid mus-cle is not innervated by the recurrent laryngeal nervebut by the superior laryngeal nerve, a condition similarto that in an adjustment for falsetto may result. In typi-cal cases of recurrent laryngeal nerve paralysis, thewavelike movement is not observed, unless there are noother pathologies, such as edema. When the paralysispersists for a long time, the vocals muscle becomes atro-phied, the muscular tissue is replaced by fibrous tissue,and the vocal fold becomes thin. The vocal fold presentsa movement similar to that of a flag flapping in thewind. When reinnervation of the vocalis muscle begins(at first, usually in only a fraction of the entire motorunits of the muscle), gradual recovery of the wavelikemovement is observed.

Summary

Histological findings of the human vocal fold indicatethat it can be regarded as a double-structured vibratorthat consists of a body and a cover. The mechanicalproperties of the two structures can vary according todifferent laryngeal adjustments or pathological condi-tions. This is reflected by changes in the vibratory modeand consequent variations in the acoustical propertiesof the glottal sound.

References

1. Hirano M. Morphological structure of the vocal cordas a vibrator and its variations. Folia Phoniatr. 1974;26:89–94.

2. Hirano M. Phonosurgical anatomy of the larynx. In:Ford, CN, Bless DM, eds. Phonosurgery. Philadelphia,Pa: Raven Press; 1991:26.

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Reproduced with permission from Folia Phoniatr. 1974;26(2):89–94. Copyright 1974 Karger.All rights reserved.

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