The Sinus Bone Graft 3rd Edition Ole T. Jensen

Mỗi năm trôi qua, tôi vẫn tiếp tục ngạc nhiên về việc chúng tôi đã tiến xa như thế nào và chúng tôi tiếp tục tiến bộ như thế nào trong quy trình nâng và ghép xoang chuyên môn cao. Chỉ cách đây vài thập kỷ, việc nâng xoang chỉ được thực hiện tại một phòng khám nha khoa tổng quát ở Opelika, Alabama; nó hiện là một sự hợp tác quốc tế đa chuyên khoa. Khi các kỹ thuật đã phát triển, cuốn sách này cũng vậy. Ấn bản thứ ba của The Sinus Bone Graft cập nhật cơ sở lý luận khoa học hiện tại và thực hành lâm sàng cho những gì tiếp tục là một quy trình cần thiết để tái tạo răng sau cấy ghép răng hàm trên. Trong tập này, sự chú ý được dành cho sự ghi nhận lịch sử của những người tiên phong trong lĩnh vực này, bao gồm Hilt Tatum, Philip Boyne và Carl Misch. Nhưng có vô số những người đóng góp vào việc nâng cao xoang, từ các thành viên của Hội nghị Đồng thuận về Xoang năm 1996 do Học viện Osseointegration tài trợ đến các tác giả của hơn 2.000 ấn phẩm hiện nay liên quan đến các sửa đổi liên quan đến điều trị sàn xoang. Vào năm 1986, tôi đã thực hiện chuyến hành hương do nhiều bác sĩ nha khoa tổng quát thực hiện trước khi tôi đến thăm văn phòng của bác sĩ Hilt Tatum và trực tiếp học hỏi từ bác sĩ lâm sàng bậc thầy. Sau khi quan sát anh ta trong vài ngày, tôi nhớ mình đã ra đi trong một cảm giác bàng hoàng tự hỏi liệu thuốc nâng xoang, như anh ta gọi, có thể là thật hay không. Mãi đến 10 năm sau, một nhóm 38 bác sĩ lâm sàng đã gặp nhau ở Boston để trình bày kết quả nâng xoang sớm của họ. Sau khi mọi người đã trình bày dữ liệu của họ, bao gồm các phương pháp khác nhau và các sửa đổi đối với quy trình ban đầu, chúng tôi đã hiểu một cách khá rõ ràng rằng tất cả chúng tôi đều đã thành công Chúng tôi ngạc nhiên, gần như im lặng, rằng công việc của Tiến sĩ Tatum đã được nhân rộng một cách nhanh chóng. Từ thời điểm đó trở đi, thế giới nha khoa cấy ghép đã thay đổi khi nâng xoang tự tin được khuyến nghị cho bệnh nhân. Một vài năm sau, sau khi cộng tác ở Thụy Điển, tôi đã có một cuộc thảo luận với PI Brånemark và Ulf Lekholm, những người vẫn xem thủ thuật xoang với sự hoài nghi. Vào thời điểm đó, bác sĩ Brånemark đang ấp ủ ý tưởng cấy ghép zygomatic và nói với tôi rằng việc ghép xoang có thể không cần thiết. Lúc đó tôi không hiểu ý của anh ấy, nhưng bây giờ thì tôi hiểu. Ngoài cái nhìn tổng quan về các loại vật liệu và kỹ thuật ghép, cuốn sách này còn có đầy đủ các lựa chọn thay thế cho ghép xoang. Trong số đó có việc sử dụng phương pháp cấy ghép zygomatic và ý tưởng rằng màng xoang nên được phản chiếu nhưng không nhất thiết phải được ghép, như Stefan Lundgren đã chỉ ra. Vào năm 2011, tôi đã gặp riêng Tatum và Boyne, hai nhà sáng tạo vĩ đại của phương pháp ghép xương sàn xoang, và đã ghi lại tận mắt quá trình suy nghĩ sáng tạo độc lập của họ. Điều thú vị là cả hai đều mô tả cảm hứng được kích hoạt bởi vấn đề thiếu không gian não bộ. Mặc dù là bác sĩ phẫu thuật, họ đang suy nghĩ như một nha sĩ phục hình, đang vật lộn với việc làm thế nào để có được chỗ cho mão răng hoặc phục hình, khi ý nghĩ đột ngột xuất hiện về việc phát triển xương “ở phía bên kia” (tức là ở sàn xoang). Việc ghép xương chưa bao giờ giải quyết được vấn đề theo cách này trước đây. Tương tự như vậy, nhiều nhà đổi mới trong cuốn sách này — những người giỏi nhất và những bộ óc sáng suốt nhất trên khắp thế giới — tiếp tục giải một phần của câu đố là y học tái tạo một cách sáng tạo. Bộ sưu tập những tiến bộ trước đây trong công nghệ ghép xoang rõ ràng sẽ không thể thực hiện được nếu không có những nhà khoa học và cải tiến này, các bác sĩ y khoa và nha khoa. Tuy nhiên, chúng ta cũng phải công nhận tất cả những người tham gia vào nghệ thuật chữa bệnh cho một con người: trợ lý phẫu thuật và nghiên cứu, nhân viên phụ trợ, gia đình hỗ trợ, và tất nhiên là bản thân bệnh nhân. Cảm ơn bạn đã cống hiến cho sự nghiệp xứng đáng này.

The Sinus Bone Graft, Third Edition

Library of Congress Cataloging-in-Publication Data

Names: Jensen, Ole T., editor

Title: The sinus bone graft / [edited by] Ole T Jensen

Description: Third edition | Batavia, IL : Quintessence Publishing Co Inc, 

   [2018] | Includes bibliographical references and index

Identifiers: LCCN 2018033872 | ISBN 9780867157918 (hardcover)

Subjects: | MESH: Maxillary Sinus surgery | Bone Transplantation methods | 

   Dental Implantation methods | Reconstructive Surgical Procedures methods

Classification: LCC RF421 | NLM WV 345 | DDC 617.5/2 dc23

LC record available at https://lccn.loc.gov/2018033872

© 2019 Quintessence Publishing Co, Inc

Quintessence Publishing Co Inc

411 N Raddant Rd

Batavia, IL 60510

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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: Marieke Zaffron

Design: Sue Zubek

Production: Sue Robinson

Printed in China

Acknowledgments

I wish to acknowledge my surgical assistants, Cindy Formanek and Jennifer Chatting,

and my auxiliary staff including Monique Stozek, Jenny Featheringill, Kathy Stenson,

and Janet Zacharias

— Ole T Jensen

THE SINUS BONE GRAFT

THIRD EDITION

Edited by

Adjunct Professor Department of Oral and Maxillofacial Surgery

School of Dentistry University of Utah Salt Lake City, Utah

Berlin, Barcelona, Chicago, Istanbul, London, Milan, Moscow, New Delhi, Paris, Prague, São Paulo, Seoul, Singapore, Tokyo, Warsaw

Foreword by Tomas Albrektsson vi

Preface vii

In Memoriam: Carl Erwin Misch viii

Contributors ix

Introduction by Hilt Tatum Jr xiii

Section I: Surgical Options for Bone Grafting

1 Bone Grafting Strategies for the Sinus Floor 1

Craig M Misch

2 Diagnosis and Treatment of Sinus Infections 15

Ashish A Patel | Eric J Dierks

3 Osteoperiosteal Flaps for Sinus Grafting 23

Ole T Jensen

4 The Alveolar Split Approach for Sinus Floor Intrusion 32

Len Tolstunov | Daniel R Cullum | Ole T Jensen

5 Complex Techniques for Posterior Maxillary Reconstruction 42

Nardy Casap | Heli Rushinek

Section II: Lateral and Transcrestal Sinus Elevation

6 Lateral Window Surgical Techniques for Sinus Elevation 48

Tiziano Testori | Riccardo Scaini | Matteo Deflorian | Stephen S Wallace | Dennis P Tarnow

7 Sinus Floor Augmentation Without Bone Grafting 66

Giovanni Cricchio | Lars Sennerby | Stefan Lundgren

8 Intraoperative Complications with the Lateral Window Technique 73

Stephen S Wallace | Dennis P Tarnow | Tiziano Testori

9 Transcrestal Window Surgical Technique for Sinus Elevation 92

Michael S Block

10 Transcrestal Sinus Augmentation with Osseodensification 105

Salah Huwais | Ziv Mazor

11 Transcrestal Hydrodynamic Piezoelectric Sinus Elevation 118

Konstantin Gromov | Sergey B Dolgov | Dong-Seok Sohn

Section III: Implant Placement in the Resorbed Posterior Maxilla

12 Lateral and Transcrestal Bone Grafting with Short Implants 128

Rolf Ewers | Mauro Marincola

13 Transsinus Implants 140

Tiziano Testori | Gabriele Rosano | Alessandro Lozza | Stephen S Wallace

14 Guided Extrasinus Zygomatic and Pterygoid Implants 151

Nardy Casap | Michael Alterman

15 Navigation for Transsinus Placement of Zygomatic Implants 159

Yiqun Wu | Feng Wang | Wei Huang | Kuofeng Hung

16 Arch-Length Threshold for Using Zygomatic Implants 169

Nicholas J Gregory | Ole T Jensen

17 Pterygoid Implants 175

Stuart L Graves | Lindsay L Graves

18 The Nazalus Implant 183

Pietro Ferraris | Giovanni Nicoli | Ole T Jensen

19 Ultrawide Implants in Molar Sites 187

Costa Nicolopoulos | Andriana Nikolopoulou

20 Restoration and Abutment Options 199

Alexandre Molinari | Sérgio Rocha Bernardes

Section IV: Evolution and Innovations in Maxillary Bone Regeneration

21 The Sinus Consensus Conference: Results and Innovations 203

Vincent J Iacono | Howard H Wang | Srinivas Rao Myneni Venkatasatya

22 Sharpey Fiber Biologic Model for Bone Formation 213

Martin Chin | Jean E Aaron

23 Using BMP-2 to Increase Bone-to-Implant Contact 227

Byung-Ho Choi

24 Tissue-Engineered Bone and Cell-Conditioned Media 235

Hideharu Hibi | Wataru Katagiri | Shuhei Tsuchiya | Masahiro Omori | Minoru Ueda

25 Tissue Engineering of the Dental Organ for the Posterior Maxilla 244

Fugui Zhang | Dongzhe Song | Ping Ji | Tong-Chuan He | Ole T JensenIndex 259

About 40 years ago, I defended my PhD thesis, Healing of Bone

Grafts, under the tutorship of P-I Brånemark I placed optical

implants in bone tissue prior to grafting and in this manner was

able to investigate what happened to the graft

microvascula-ture after transplantation Even if allogeneic or heterologous

bone was available at the time (eg, in the Oswestry and Kiel

bone banks), it was generally agreed that only autogenous bone

provided adequate repair Bank bone was mainly used for large

orthopedic defects as a last resort Some 20 years later, I

partic-ipated in the consensus conference on sinus grafts arranged in

the United States At the same time, results of sinus grafts were

so successful that it seemed irrelevant whether autogenous,

allogeneic, or heterologous grafts were used Lamentably, the

clinical material available at the time was data collected from

clinicians rather than data printed in peer-reviewed journals,

and this seldom allows for a critical scientific analysis

Never-theless, it was the first time I had heard colleagues claim that

similar good clinical results could be achieved with types of

grafts other than the conventionally used autograft

Today, of course, we have a large bulk of evidence that many

types of bone grafts function very well when placed in sinuses

Admittedly, as evidenced in one chapter of the present volume,

in some cases we do not necessarily see improved clinical results

of implants after grafting compared to nongrafting—the

prepa-ration of bone tissue may provide a satisfactory supply of

autoge-nous bone particles for clinical success However, this type of

very simple autografting may not work in severely resorbed

clinical cases, and clinicians trying it in cases with 2 to 4 mm of

bone thickness are advised to carefully check implant stability

after placement

One commonly used source of sinus graft material today can

be heterologous bone such as Bio-Oss (Geistlich) We

investi-gated the long-term fate of sinus-grafted Bio-Oss particles 11

years after grafting and found them largely unchanged in size

and morphology.1 These particles, like the implant, may

repre-sent a foreign body with osteoconductivity (ie, new bone growth

that explains the good clinical results achieved) In fact, the

clinical fate of autografts may be quite similar in behavior We

analyzed the histologic outcome of small autogenous bone

colu-mellas used to replace the ossicular bones in hearing impairment

in humans The actual grafts had died, but they continued to function clinically with clear evidence that new live bone grew

on the surfaces of the old grafts.2

The main reason why a volume such as the third edition of

The Sinus Bone Graft is so important depends on the clinical

reports made available Sinus grafts are indeed most positive for patient treatment and have since long proven their clin-ical efficacy Dr Jensen, the editor of this book, is one of very few in the world who has experience from more than 30 years working with sinus grafts, and I can think of no one more suited

to be editor of this volume He has put together a great number

of excellent contributors to write about their experiences with sinus grafts under different conditions This book is highly recommended to anyone using oral implants, and since major innovations have been presented in this third edition, I would even recommend it to those who already own the previous editions

Tomas Albrektsson, md , phd

Professor EmeritusDepartment of BiomaterialsInstitute of Clinical SciencesGothenburg University Gothenburg, SwedenVisiting Professor Faculty of OdontologyMalmö UniversityMalmö, Sweden

deprotein-2 Kylén P, Albrektsson T, Ekvall L, Hellkvist H, Tjellström A

Surviv-al of the corticSurviv-al bone columella in ear surgery Acta Otolaryngol 1987;104:158–165.

With each passing year, I continue to be amazed at how far

we have come and how we continue to advance in the highly

specialized procedure of sinus elevation and grafting Only a

few decades ago, the sinus elevation was performed in just

one general dental office in Opelika, Alabama; it is now an

international cross-specialty collaboration As the techniques

have evolved, so has this book The third edition of The Sinus

Bone Graft updates current scientific rationale and clinical

prac-tice for what continues to be a necessary procedure for

poste-rior maxillary dental implant reconstruction In this volume,

attention is given to historical recognition of pioneers in this

field, including Hilt Tatum, Philip Boyne, and Carl Misch But

there are countless contributors to sinus elevation, from the

members of the 1996 Sinus Consensus Conference sponsored

by the Academy of Osseointegration to the authors of the now

over 2,000 publications concerning modifications related to

sinus floor treatment

In 1986, I made the pilgrimage taken by many general dentist

implantologists before me to visit Dr Hilt Tatum’s office and

learn firsthand from the master clinician After observing him

over a few days, I remember leaving in a kind of daze

wonder-ing if a “sinus lift,” as he called it, could be real It wasn’t until

10 years later that a group of 38 clinicians met in Boston to

present their early sinus elevation results After everyone had

presented their data, including disparate methods and

modifi-cations to the original procedure, we came to understand quite

remarkably that we all had success! We were stunned, almost

to silence, that Dr Tatum’s work had so summarily been

repli-cated From that point forward, the world of implant dentistry

changed as the sinus elevation was confidently recommended

to patients

A few years later, after having collaborated in Sweden, I had

a discussion with P-I Brånemark and Ulf Lekholm, who still viewed the sinus procedure with skepticism At the time, Dr Brånemark was hatching the idea of the zygomatic implant and told me that the sinus graft might not be necessary after all I did not understand his meaning then, but I do now In addition to

an overview of the types of graft material and techniques, this book is filled with alternatives to the sinus graft Among them are the use of the zygomatic implant and the idea that the sinus membrane should be reflected but not necessarily grafted, as Stefan Lundgren has shown

In 2011, I met separately with Tatum and Boyne, the two great innovators of the sinus floor bone graft, and recorded their independent creative thought processes firsthand Interestingly, they both described inspiration being triggered by a problem of deficient interocclusal space Though surgeons, they were think-ing as restorative dentists, struggling with how to obtain room for crowns or a prosthesis, when the sudden thought occurred

of developing bone “on the other side” (ie, on the sinus floor)

Bone grafting had never solved a problem in this way before

Similarly, many of the innovators in this book—the best and the brightest minds throughout the world—continue to creatively solve a portion of the riddle that is regenerative medicine

This collection of prescient advancements in sinus graft nology would clearly not be possible without these innovators and scientists, the doctors of medicine and dentistry However,

tech-we must also recognize all those who participate in the art of healing a human being: the surgical and research assistants, auxiliary staff, supportive families, and of course the patients themselves Thank you for your devotion to this worthy cause

Ole T JensenPREFACE

Carl Erwin Misch, dds , mds

“Being his brother I could feel I live in his shadow, but I never

have and do not now I live in his glow.”—Michael Morpurgo

In 2017, the dental profession and implant field lost a true

icon: my brother, Dr Carl E Misch Carl often stated that his

professional goal was to elevate the standard of care in implant

dentistry, and he worked tirelessly in pursuit of that

achieve-ment He had a gift for organizing and simplifying information

and used that gift to develop numerous principles and

classifi-cations that became integral concepts in the origins of modern

implant dentistry Carl had the good fortune to meet Dr Hilt

Tatum in the late 1970s and to be taught sinus bone grafting

techniques from one of the originators of the procedure He had

exceptional clinical skills and was one of the first

prosthodon-tists in the United States to perform complex implant surgeries

In 1987, Carl published the first classification for managing

the posterior maxilla based on the amount of bone below the

sinus These practical guidelines are still relevant today and

were included in the second edition of The Sinus Bone Graft He

was also an early proponent of using bone substitutes for sinus

grafting and presented his data alongside me at the first Sinus

Consensus Conference at Babson College in 1996

Carl had a passion for learning and sharing information He founded the Misch Implant Institute, a continuing education program with an organized curriculum on implant dentistry He was also on the faculty at several dental schools and served as director of one of the first university-based implant programs at the University of Pittsburgh from 1986 to 1993 His lectures—

enthusiastic, authoritative, charismatic, and personal—always captured the audience’s attention This text, Contemporary Implant Dentistry (Mosby/Elsevier, 1993), was one of the

first books detailing sinus anatomy, physiology, and surgical approaches to manage the atrophic posterior maxilla This text

is now in its third edition and is considered by many as the most complete reference on surgical and prosthetic implant topics

Carl was a prolific author and published over 100 peer-reviewed articles on various implant-related topics His commitment to the profession truly changed the lives of his students, colleagues, and patients Dr Carl Misch was a true pioneer, leader, profes-sor, and master clinician of implantology He had a remark-able career, and we will all miss his influence and passion for implant dentistry

Craig M Misch

Dr Carl Misch (left) and Dr Craig Misch (right) at the

Academy of Osseointegration Annual Meeting, 2016

CHAPTER 1 9

CONTRIBUTORS

Jean E Aaron, p d

Bone Structural Biologist and Visiting Lecturer

School of Biomedical Sciences

University of Leeds

Leeds, United Kingdom

Michael Alterman, dmd

Director of Outpatient Clinic

Hadassah and Hebrew University Medical Center

Jerusalem, Israel

Sérgio Rocha Bernardes, bds , ms c , p d

Head of New Product Development and Clinical Practice 

Professor and Chairman

Department of Oral and Maxillofacial Surgery

Hadassah and Hebrew University Medical Center

Jerusalem, Israel

Martin Chin, dds

Private Practice Limited to Oral and Maxillofacial Surgery

San Francisco, California

Byung-Ho Choi, dds , p d

Professor

Department of Oral and Maxillofacial Surgery

Wonju College of Medicine

Loma Linda, CaliforniaGuest LecturerDepartment of Oral and Maxillofacial SurgeryUniversity of California, Los Angeles

Los Angeles, California

UT Southwestern/Parkland Memorial Hospital

Dallas, Texas

Stuart L Graves, dds , ms

Private Practice Limited to Oral, Maxillofacial,

and Implant Surgery

Private Practice Limited to Periodontics

and Implant Dentistry

Associate Professor and Director

Molecular Oncology Laboratory

Department of Orthopaedic Surgery and Rehabilitation

The Affiliated Hospital of Stomatology

Chongqing Medical University

Chongqing, China

Hideharu Hibi, dds , p d

Professor and Chair

Department of Oral and Maxillofacial Surgery

Nagoya University Graduate School of Medicine

Nagoya, Japan

Wei Huang, dds , ms

Professor

Department of Oral Maxillofacial Implantology

Ninth People’s Hospital

Salah Huwais, dds

Adjunct Assistant Clinical Professor Department of Restorative SciencesSchool of Dentistry

University of MinnesotaMinneapolis, MinnesotaPrivate Practice Limited to Periodontics and ImplantologyJackson, Michigan

Vincent J Iacono, dmd

SUNY Distinguished Service Professor, Tarrson Family Professor of Periodontology and Chair

Department of PeriodontologyDirector of Postdoctoral EducationStony Brook School of Dental MedicineStony Brook, New York

Ole T Jensen, dds , ms

Adjunct ProfessorDepartment of Oral and Maxillofacial SurgerySchool of Dentistry

University of UtahSalt Lake City, Utah

Ping Ji, dds , p d

Professor and PresidentChongqing Key Laboratory of Oral DiseasesNational Clinical Research Center for Oral DiseasesThe Affiliated Hospital of Stomatology

Chongqing Medical UniversityChongqing, China

Wataru Katagiri, dds , p d

Associate ProfessorDivision of Reconstructive Surgery and Oral and Maxillofacial Region

Niigata University Graduate School of Medical and Dental Sciences

Niigata, Japan

Alessandro Lozza, md

Chief Assistant and Senior ConsultantNeurophysiopathy Service, IRCCS Mondino FoundationPavia, Italy

Stefan Lundgren, dds , p d

Professor and Chairman

Department of Oral and Maxillofacial Surgery

Umeå University

Umeå, Sweden

Mauro Marincola, dds , ms

Professor and Clinical Director

International Implantology Center

Department of Implant Dentistry

Stony Brook School of Dental Medicine

Stony Brook, New York

Giovanni Nicoli, md

Maxillofacial Surgery Specialist

ASST Vallecamonica Hospital

Masahiro Omori, dds , p d

Postdoctoral ResearcherDepartment of Oral and Maxillofacial SurgeryNagoya University Graduate School of MedicineNagoya, Japan

Ashish A Patel, dds , md

Consultant at a Private Practice Limited to Head and Neck Surgery

Associate ProfessorDepartment of Oral and Maxillofacial SurgerySchool of Dentistry

Oregon Health and Science University Portland, Oregon

Gabriele Rosano, dds , p d

Oral SurgeonLake Como InstituteComo, Italy

Heli Rushinek, dmd

Oral and Maxillofacial SurgeonDepartment of DentistryHadassah and Hebrew University Medical CenterJerusalem, Israel

Riccardo Scaini, dds

Tutor at the Section of Implant Dentistry and Oral RehabilitationDepartment of Biomedical, Surgical, and Dental SciencesIRCCS Istituto Ortopedico Galeazzi

University of MilanMilan, Italy

Lars Sennerby, dds , p d

ProfessorInstitute of OdontologySahlgrenska AcademyUniversity of GothenburgGothenburg, Sweden

Dong-Seok Sohn, dds , p d

Professor and ChairDepartment of Oral and Maxillofacial SurgeryCatholic University Medical Center of DaeguDaegu, South Korea

Medicine

University of Chicago Medical Center

Chicago, Illinois

State Key Laboratory of Oral Diseases

National Clinical Research Center for Oral Diseases

West China Hospital of Stomatology

Sichuan University

Chengdu, China

Dennis P Tarnow, dds

Clinical Professor and Director of Implant Education

College of Dental Medicine

Columbia University Irving Medical Center

New York, New York

Adjunct Clinical Associate Professor

Department of Periodontics and Oral Medicine

University of the Pacific

Assistant Clinical Professor

School of Dentistry

University of California, San Francisco

Private Practice Limited to Oral and Maxillofacial Surgery

San Francisco, California

Shuhei Tsuchiya, dds , p d

Assistant Professor

Department of Oral and Maxillofacial Surgery

Nagoya University Graduate School of Medicine

Feng Wang, dds , md

Assistant ProfessorDepartment of Oral Maxillofacial ImplantologyNinth People’s Hospital

School of MedicineShanghai Jiao Tong UniversityShanghai, China

Howard H Wang, dds , ms , mph , mba

Private Practice Limited to Endodontics, Periodontics, and Implant Dentistry

New York, New York

Yiqun Wu, dds , md

ProfessorDepartment of Oral ImplantologyNinth People’s Hospital

Second Dental ClinicSchool of MedicineShanghai Jiao Tong UniversityShanghai, China

Fugui Zhang, dds , p d

Molecular Oncology LaboratoryDepartment of Orthopaedic Surgery and Rehabilitation Medicine

University of Chicago Medical CenterChicago, Illinois

Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences

The Affiliated Hospital of StomatologyChongqing Medical UniversityChongqing, China

Hilt Tatum Jr, dds

When Dr Jensen contacted me about contributing to this third

edition, I was uncertain It had not been possible for me to

participate in the Sinus Consensus Conference, and at the time

I had not read his book After reading the second edition, I

real-ized it would be an honor to participate in this one

The Preparation

My journey leading to the sinus augmentation procedure started

in 1956, when I attended the first course on oral implants given

in an American dental school, the Emory University School of

Dentistry The course was presented by Col Roy Bodine My

clinical experience began with 2 years of service in the Marine

Hospital located in Savannah, Georgia The next 2 years were

spent doing full-mouth restorative dentistry in Savannah before

I joined my father, Hilt Tatum Sr, and brother, Crawford Tatum,

DDS, in Opelika, Alabama There, our practice quickly became

oriented to extensive restorative dentistry

We recognized patients’ and our own dissatisfaction with

free-end partial dentures and felt that this need could be met

with the use of endosteal implants and fixed restorations In an

attempt to fix the problem, we acquired two sheets of

commer-cially pure titanium, 0.25 inch thick and 0.75 inch thick Using

these sheets, we began to make and successfully use endosteal

implants with different shapes that were designed to fit into the

available bone found in different patients After the implants

were placed, we waited to load them until after a healing period

similar to that used for mandibular fractures However, because

most of these patients had worn partial dentures for extended

periods of time, we recognized the severe vertical bone loss and

the need to restore the missing bone before the patients could

on your private restorative patients, it will bury you with the complications you will encounter.” This completely stopped our efforts toward bone construction for some time

Don Tillery, an oral surgeon and close friend, was aware of the preparation we had done and the effect that Dr Morgan’s advice had on our plans In early 1969, Don called and said that

he had seen a technique that he thought would safely meet our goal He told me about an oral surgeon, Dr James Alley, who had successfully done a series of preprosthetic bone augmen-tations on edentulous mandibles before denture construction

We contacted Dr Alley, and he invited us to visit his office We spent a week with him, observed two surgeries, and were able

to see several patients who were at different periods of time postsurgically The technique consisted of placing an autoge-nous rib (with no screws) on an edentulous mandible This was followed by a 6-month unloaded healing period and then the construction of a new mandibular denture He reported no postoperative healing complications

The secret to Dr Alley’s success was in making two vertical incisions in the vestibule of each canine area, tunneling and mobilizing the soft tissue over the entire mandible, decorticat-ing the crest of the mandible, shaping and placing the rib, and closing the remote incisions The secret therefore was good asepsis, no incisions over the graft material, decortication, and

an unloaded healing period One patient who had worn the postoperative denture for 2 years appeared to have very little

of the augmentation left

These were our takeaways from this visit:

• Surgical asepsis would be critical

• Decortication aided the augmentation union with the

mandible

• Remote incisions had prevented postoperative infections

• Loading of the denture had largely destroyed the newly

formed crestal bone

• Placement of endosteal implants should not destroy the new

crestal bone

• Placement of endosteal implants should internally load and

stimulate new crestal bone

• Most importantly, we could safely begin to restore alveolar

bone

In January of 1970, we performed the first of four successful

autogenous rib augmentations on posterior edentulous

mandi-bles (Fig 1) harvested by Dr William Lazenby Following his

suggestion, we later began using the ilium as a bone source Over

a period of 9 years, Dr Lazenby and Dr Doyle Hanes routinely

harvested bone for our augmentation patients (Fig 2) until I

relocated my practice to St Petersburg, Florida, in 1979 Because

all of these patients were treated in a hospital environment with

remote incisions and Millipore filters (MilliporeSigma) over

the augmented bone, we experienced a very limited number

of postoperative surgical complications

I have had the opportunity to give more than 2,000 podium

presentations demonstrating these principles of creative remote

incisions for all augmentation locations These have been

presented to a wide range of dental meetings, practitioners,

and specialists It surprised me that a large majority of alveolar

augmentations have continued to be completed with crestal

incisions over the augmentation material, sometimes resulting

in complications With good asepsis, remote incisions, adequate

tissue mobilization, effective augmentation material, and precise

tissue closures, complication rates will be significantly reduced

We also found that augmented bone remained stable after implant placement, healing, and restoration We did observe that when large augmentations were done within the esthetic zone, it was wise to maintain patients with provisional resto-rations in function for a period of 2 years before the definitive restorations were placed This resulted in the most desirable esthetic results

The Sinus Procedure

As our augmentation experience progressed, we recognized that

it was impossible to do a vertical onlay augmentation in a rior maxilla with no vertical loss and a severely pneumatized sinus without infringing on the vertical space required for the dental restorations For the longest time, this seemed an insur-mountable challenge Then, in 1974, the thought occurred to

poste-me that we were looking at the problem backward and should

be putting the bone inside of the sinus rather than on the crest

Immediately after this epiphany, I had parallel feelings of both exhilaration and fear I was exhilarated by the thought that it might be possible, but the fear was that which any dentist might have on considering contact with a maxillary sinus

During the remainder of 1974, we placed a number of rior maxillary implants in the following way We would either machine a titanium implant or cast a Vitallium implant that would fit into the medullary space between the sinus floor and the crest of the ridge (Fig 3) We also cast a try-in that had the same side dimensions but was longer than the implant A remote palatal flap was lifted to expose the ridge crest, and curettes were used to prepare the implant site by removing bone to the floor

poste-of the sinus to match the dimension poste-of the implant The try-in was then fitted into this socket and lightly tapped to release the sinus floor The floor and mucosal lining were vertically elevated a few millimeters, and some of the curetted bone was

Fig 1 Autogenous rib with one thickness (a)

and two thicknesses (b) from 1970.

Fig 2 (a and b) By 1980, we were using

au-togenous iliac bone for the maxilla and eral sinuses done with two vertical vestibular incisions.

bilat-The Sinus Procedure

placed into the space around the elevated floor The implant

was then placed into the deepened socket and additional bone

was placed over the implant to the crest of the ridge, with only

the implant neck exposed The flap was rotated and sutured

on the palatal wall The healing around each of these implants

was uneventful, and they were restored

We have always referred to this procedure as a sinus lift By

1980, we had modified the technique into compressing the

cancellous bone threads into an intertwined mat that could

elevate the floor as it deepened the socket without entering the

sinus (Fig 4) We now use these bone manipulation osteotomes

to form the sockets, compress the cancellous bone, and elevate

the sinus floor

Our first sinus augmentation with autogenous, particulate,

iliac bone was done in February of 1975 This, along with our

next four augmentations, was done from the crest of the ridge

and opened with a palatal flap We then began to primarily use

a crestal incision and prepare a sinus window anterior to the

zygomatic buttress on the lateral wall of the maxilla However,

our fear of the word sinus was so strong that in the hospital

operative notes, we would describe the operation as an inverted

maxillary bone graft

At the 1976 Alabama Implant Congress meeting in

Birming-ham, Alabama, we reported on the sinus augmentation

proce-dure and the results we had observed during the previous 15

months I was invited to make a presentation in the fall of 1977

on sinus augmentation at the American Academy of Implant

Dentistry annual meeting and asked Dr Philip Boyne to join

me In a 1994 meeting of the Alabama Implant Congress (at

the same podium from which I first presented in 1976), he

confirmed our success with this procedure before an audience

of more than 300 attendees

During the first several years of sinus augmentations, we had

limited instruments and relied heavily on modified Fogarty

catheters to aid in the elevation of the sinus membrane These

were shortened to a few inches long and attached to a syringe

When slid under the sinus lining and gently inflated, they could

safely lift the membrane (Fig 5) By 1978, we had created

suit-able instruments and no longer needed the Fogarty catheters

Until 1984, autogenous iliac bone was our primary

augmenta-tion material However, from 1972 until 1982, we were furnished

some frozen human allograft by Dr Bill Hiatt from the VA-funded

study, 1962–1982, for which he was a codirector We established and maintained the same cryogenic banking capability as was used in the study and would always have a suitable human lymphocyte antigen match between the donor and recipient for anyone treated with this bone Results comparable with autogenous bone were observed on the sinus augmentation patients treated with this allograft

From 1978 forward, we began to utilize a titanium root form system I had developed, which became the first titanium root form system with FDA marketing approval (Fig 6) This system also included a selection of designs that were used to elevate the sinus floor and used the curetted bone that was harvested during the socket preparation (Fig 7)

From 1979 until 1983, we did the surgical cases for the US Food and Drug Administration (FDA) preclinical study on tricalcium phosphate ceramic (TCP) as a bone augmentation material We evaluated and found this product to be success-ful for sinus augmentations, though slower in its replacement than human bone

In the summer of 1982, Martin Lebowitz, DDS, MS, left the chairmanship of the OMS Department at the University of Flor-ida School of Dentistry to join me Following this, many of the

Le Fort I surgical cases also had simultaneous sinus tations Martin was left-handed and I was right-handed, which allowed us to both operate at the same time with the following steps:

augmen-• Careful attention was given to achieve optimum asepsis within each nasal passageway during preparation and intubation

• After maxillary downfracture, a careful, meticulous freeing

of the nasal mucosa from bone to prevent tears in this tissue was done This was important to protect the augmentation material from risk of contamination from bacterial flora occurring in the nose

• We also provided a hyperbaric oxygen chamber within our office to aid in the management of potential anaerobic infections

In 1984, my son, Hilt Tatum III, DMD, joined our practice

During that same year, multiple augmentation products became available with the freeze-dried demineralized bone products reported as the most favorable We used multiple products for

Fig 3 Custom-made implants elevating the sinus floor and

custom-made root form from 1974.

Fig 4 Sinus floor elevated by compressing bone and with- out entering the sinus.

Fig 5 Inflated Fogarty catheter elevating the

sinus membrane.

sinus augmentations during this period, but by 1986, our

clin-ical results were varied and confusing We decided to evaluate

each class of products by comparing results with

histomor-phometric evaluations taken from bilateral sinuses in the 4th

postoperative month We obtained three to five results from

each type of the tested materials and were surprised by what

we found The best results (37% new bone) were obtained from

irradiated cancellous human bone (ICB, Rocky Mountain Tissue

Bank), and the second best was from 1- to 2-mm demineralized

freeze-dried cortical bone chips (12% new bone)

Since 1988, the ICB from Rocky Mountain Tissue Bank has

been our product of choice for sinus augmentations This

recog-nition that ICB provided a sinus augmentation product

compa-rable with autogenous bone permitted a readily available and

reliable material for in-office surgical procedures Also, this

product allowed us to perform lateral wall augmentations and

place root-form implants rather than the special sinus implants

The average amount that we have used for each sinus has

been 7 g

In the mid-1990s, I designed and made a number of

instru-ments to improve our ability to perform sinus procedures

These included flap retractors to fit over different shapes found

on zygomatic buttresses and curettes made to fit the

differ-ent anatomical areas found within sinuses These instrumdiffer-ents

have significantly simplified and improved the precision of the

surgeries

Even when following a strict protocol under exact specified

patient conditions, complications may occur When a tear is

present in the mobilized mucosal lining, excess tissue is folded

over the tear and stabilized with a shaped collagen tape just prior

to placing the bone The tape will momentarily adhere to the

lining, and by placing the bone immediately against the tape,

it will stabilize the tape and hold the torn tissue in position

When postoperative infections occur, they will typically become

symptomatic within a few days after the surgical procedure

Immediate attention, including culture and sensitivity testing,

modification or expansion of antibiotic coverage with

thera-peutic doses, and further modification as directed following

sensitivity testing, has proven to be effective in the majority of

patients If this does not completely eliminate the symptoms

within a period of 7 to 14 days, removal of all augmentation

material is usually indicated If implants were placed during the augmentation procedure, this regimen would not be expected

to be successful as a result of the biofilm-shielded bacterial colonies growing and shielded on the implants In our 43 years

of sinus augmentations, we have lost the grafts in less than 1%

of the sinuses treated

Vascularized Osteotomies

By 1980, we recognized that sinus and interpositional bone augmentations as well as free-flap procedures were safer and more precise than onlay procedures Hoping to demonstrate this, I took a training course in microvascular surgery We then attempted to replace onlay autogenous procedures with free-flap microvascular procedures using autogenous iliac sources

Though we could make the microvascular connections, we found that developing the correct bone shapes in the precise locations needed on the alveolar ridges was like fitting a square peg in a round hole Still, the idea fascinated me, and in early

1982, we did a maxillary vascularized osteotomy procedure attempting to achieve a free-flap result by using the natural alveolus with its blood supply and without the need for micro-vascular surgery

This was successful, so we published a paper on maxillary augmentations with the technique and have developed and expanded its utilization through the years.1 It instantly produces the results sought with a distraction osteogenesis procedure with minimal or no hardware Typically, a long titanium screw (ie, 18 to 24 mm) is used to stabilize the vertically moved bone

ICB and irradiated corticocancellous (ICC) blocks are used for the interpositional material (Fig 8) Alterative vertical stabiliza-tion can be achieved with miniplates or ICC blocks It is true that the shape of a healed alveolar ridge is not the shape of an alveolus surrounding teeth However, the plasticity of vascu-larized alveolar bone, combined with the correct instruments, knowledge, and skill of bone manipulation, makes it possible

to transform the vertically corrected but misshaped bone into

a perfect socket An implant can then be crestally positioned within the same location previously occupied by the root it is

Fig 6 (a and b) Transmucosal implants and soft tissue reconstruction in augmented maxilla

and bilateral sinuses.

Fig 7 Sinus implant selection and try-ins This photograph shows 4 of the 16 sizes made.

Vascularized Osteotomies

replacing (Figs 9 and 10) The correct use of this concept will

produce the safest, simplest, and most precise correction of a

vertical deficiency

We have used this to perform office procedures with

intra-venous sedation and local anesthesia, including the following:

• Move healed implants (Fig 11)

• Move segments of teeth and bone (Fig 12)

• Correct single implant sites (Fig 13)

• Move multiple edentulous segments (Fig 14)

• Correct vertical defects simultaneously with sinus tations (Fig 15)

augmen-• Move full maxillary arches (Fig 16)The safety lies in the maintained vascularity and vitality of the bone, surgical asepsis, the interpositional location of the augmentation material, and the remoteness of the incisions

We have described this procedure as a Tatum vascularized osteotomy (TVO).

Fig 8 (a to d) Tatum vascularized osteotomy

(TVO) The goal is to regain bone attachment

in the mandible by using a vertical fixation

screw and implants.

Fig 9 (a to d) Bone expansion, implant, and

restorative treatment by Dr Jose Pedroza.

Fig 10 (a to d) Bone expansion, implants,

and restorative central crown restorations by

Dr Ana Ayala.

Fig 11 (a to d) TVO used to move an implant.

Fig 12 (a) Preoperative maxillary extrusion and an extreme buccal relationship (b) TVO to correct abnormality and with implants placed (c)

Completed case with restorations by Dr Jose Pedroza.

The Future of Sinus Augmentations

The Future of Sinus

Augmentations

It is our opinion that the future of the sinus augmentation

procedure will include the simultaneous correction of vertical

deficiencies For a number of years, over half of the sinuses we

have augmented have had simultaneous vertical corrections

These have been accomplished with either a TVO or an onlay

block, and we will describe both When a block is to be placed,

an incision is made one tooth and one papilla anterior to the

edentulous area and the same palatally to the midline or beyond,

and a full-thickness flap is rotated over this tooth to prevent

any incision from being present over the block This flap must

be completely elevated from the maxilla, including a buccal cut

through the periosteum

When the TVO is indicated, it can be correctly done and the implants later placed with bone manipulation The TVO is safer than an onlay and produces the most precise results The greater challenge here is that this requires the implant placements to

be done with bone manipulation; this is a skill and an art that requires patience and training The further complication is that

we have a limited number of instructors with these special skills

The TVO technique

Bone cuts are made with a set of microtomes that are designed for this procedure The greater palatine vascularity to the soft tissue and bone should be preserved The sinus elevation is completed as described previously and must be above the level

of the hard palate All bone cuts are made from the buccal without penetrating the palatal soft tissue and with progressive

Fig 15 Simultaneous sinus augmentation and

TVO, implants with bone expansion and

manip-ulation of gingiva (a) Preoperative (b)

Post-operative.

Fig 16 (a to d) Full maxillary alveolus moved

8 mm down and 4 mm forward and crossbite

correction all as in-office procedures.

microtomes (5 mm, 7.5 mm, 10 mm, 12.5 mm, and 15 mm) to

produce a straight cut

The anterior vertical cut is anterior to the vertical deficiency

and is made through the alveolus to the level of the hard palate

Note that roots are never stripped of bone A horizontal cut is

made through the sinus and palatal slope just below the hard

palate and anterior to the greater palatine foramen The distal

vertical cut is made through the tuberosity to the level of the

hard palate or as a separation between the pterygoid plates and

the maxilla to that level

A superficial horizontal bone cut to protect the greater

pala-tine bundle is made with a wide microtome to the distal vertical

cut in the area of the greater palatine foramen The microtome

is then rotated downward to complete the horizontal fracture

A periosteal elevator is slid through this horizontal cut

(ante-rior to the greater palatine) to elevate and mobilize the soft

tissue from the hard palate over to or across the midline (artery

is safely within this tissue)

A semicircular incision is made (facing the surgical site) in

the tissue over the hard palate This permits the segment to

be moved downward as this flap slides laterally—the greater

palatine artery is avoided and always protected The exposed

bone will granulate over in 2 weeks

The shaped collagen tape is placed against the sinus lining A

layer of ICB mixed with antibiotic is placed against the collagen

tape to stabilize the collagen A premade stent will be used to

vertically position the mobilized bone, and it will be stabilized

with ICC blocks, vertical screws, plates, and ICB to complete

filling the sinus space below the elevated lining A stent or

dressing will be placed to hold this advanced soft tissue flap against the hard palate to create a fibrin seal (Fig 17)

When a vertically deficient maxilla is indicated for a sinus augmentation and the shape is not appropriate for a TVO, an ICC onlay block is indicated The best results will be achieved

by designing the flap to have no incisions over the augmentation and for the flap to be fully vascularized There are a number

of creative incision designs that can be used to provide access, maintain vascularity, reposition gingiva, or all of these tasks (Fig 18)

Conclusion

In 1977, we included this quote in our presentation: “The goal of modern implantology is to accept for treatment a patient at any stage of dental disease, atrophy, or trauma and—with general health permitting—restore them to normal contour, comfort, function, esthetics, and health.” Carl Misch opened each of his books with these goals After 42 years and our over 2,800 sinus augmentations, this procedure has allowed us and many others

to achieve these goals for countless patients

Reference

1 Tatum H Jr Endosteal implants CDA J 1988;16(2):71–76.

Fig 18 Onlay block and sinus augmentation showing (a) incision, (b) remote vascularized flap elevation, and (c) occlusal view of block in place,

palatal tissue, and area to granulate.

Fig 17 (a) After the elevation, collagen is placed against the lining (b) ICB is placed, and a stent is added to allow placement of bone blocks

with a screw for stabilization (c) Palatal view of completed surgery and area to granulate.

Collagen

ICB bone Two bone blocks (ICC block) Screw

Collagen

ICB bone Two bone blocks (ICC block) Screw

ICB bone Two bone blocks (ICC block) Screw

CHAPTER 1

BONE GRAFTING STRATEGIES

FOR THE SINUS FLOOR

Craig M Misch, dds, mds

Aprimary diagnostic consideration of dental implant

placement in the maxilla is the bone volume of the residual ridge In the posterior maxilla, the maxil-lary sinus often limits the available bone for implant placement The clinician can avoid the sinus by either selecting

a shorter implant size or tilting the implant position away from

the sinus cavity Another option is to elevate the sinus mucosa

to establish a new sinus floor at a more superior level The goals

of the sinus elevation procedure are to augment bone height

in the posterior maxilla for dental implant placement, promote

the development of a bone-to-implant interface contact, and

enable long-term survival of the implants under prosthetic

load-ing This chapter discusses various strategies for managing the

sinus floor, including surgical approaches, graft materials, and

future directions

Indications for Sinus Bone Grafting

During growth of the facial skeleton, the sinus cavities expand

in volume The floor of the maxillary sinus is often in close

approximation to the posterior tooth roots When posterior

teeth are lost, the sinus further expands, reducing the amount of

residual bone Following extraction of the posterior teeth, there

is also a loss of facial bone, resulting in medial resorption of the

maxillary ridge In addition, the edentulous posterior maxilla

often has poorer bone quality These conditions can

compro-mise the placement of dental implants for prosthetic support

The management of maxillary atrophy and sinus

pneumati-zation for dental implant placement has evolved over the years

When sinus bone grafting was first developed, clinicians favored

the use of longer dental implants This was thought necessary

for optimal biomechanical loading of the implant and prosthetic

support In addition, shorter machine-surfaced implants (< 10

mm) showed lower survival rates in the posterior maxilla.1

Under these constraints, it was often necessary to perform sinus bone grafting through a lateral window approach to allow place-ment of longer implants An early classification protocol recom-mended lateral window sinus bone grafting when there was 8

mm or less of bone height below the sinus floor for placement

of the maximum implant length (> 15 mm).2

However, improvements in implant materials, design, and surface properties have now led to the use of shorter dental implants Many studies have even shown that the survival

of short implants is the same as longer implants placed into grafted sinuses.3,4 Compared with short implants, sinus bone grafting has a higher incidence of complications, costs more, and requires additional surgical and healing time However, short implants do have a higher risk of failure during the early healing period, which may be due to their reduced stability in softer bone.5

A clinical trend is to use shorter implant lengths in the rior maxilla (Fig 1-1) This reduces the volume of bone grafting that is needed for implant placement and may even avoid the need for sinus augmentation It may also allow the surgeon to consider an osteotome sinus floor elevation for short implant placement rather than using a lateral window technique.6 For example, a vertical bone height of 6 mm below the sinus floor would allow placement of a 6- to 9-mm implant via a trans-crestal osteotome approach Although there is no definitive bone dimension needed before considering sinus bone grafting, there is a lack of substantive long-term data on shorter implants (< 8 mm) in the posterior maxilla The decision to place short implants versus sinus grafting for longer implants should be based on long-term studies, implant design, sinus pathology, surgical experience, and patient preferences.3 The need for sinus bone grafting is also reduced by using tilted implants to avoid the sinus and zygomatic implants that may be placed through

poste-or lateral to the maxillary sinus

Section I

Simultaneous Versus Delayed

Implant Placement

The decision to place dental implants simultaneous with sinus

bone grafting or staging placement after graft healing depends

on several factors: the quantity and quality of bone below the

sinus, implant design, clinical conditions, and experience of the

surgeon The advantages of simultaneous grafting and implant

placement are decreased morbidity, lower costs, and shorter

treatment duration The edentulous posterior maxilla typically

has a thin outer cortex with softer quality trabecular bone, and

the sinus floor is a thin cortical shell As such, the minimum

bone height needed to place an implant simultaneous with

graft-ing is approximately 4 to 5 mm.7 Experienced clinicians may

be able to use methods to enhance primary implant stability

in sites with less bone, such as underpreparing the osteotomy,

osteotome expansion, osseodensification, and/or using tapered

implants.8 Autogenous or allogeneic block bone grafts fixed to

the sinus floor with implants have also been utilized.9

However, implant placement into sites with minimal residual

bone may have higher risks of complications such as implant

displacement and implant failure.10,11 If large sinus mucosa

perforations are encountered during the augmentation

proce-dure, it may be prudent to stage implant placement after graft

healing Grafting for simultaneous implant placement may be

accomplished along the sinus floor via a lateral window or

trans-crestal approach Another option is to place implants without

any bone graft material, allowing the implant apices to tent the

sinus membrane so blood clot or platelet concentrate alone can

be used to provide enough matrix for bone ingrowth

Delayed implant placement is performed after healing of a bone graft The healing time may vary depending on the graft material used Autogenous bone grafts heal faster, so using auto-graft as the sole material or combining it with bone substitutes can shorten the healing time requirements to 4 to 6 months.12

The use of a slow-resorbing graft material, such as bovine bone mineral or hydroxyapatite, may necessitate longer healing peri-ods well exceeding 6 months.13 The bone graft material does not have to be completely incorporated before implant place-ment because additional healing time is allowed for implant integration, but the total healing period may still exceed 1 year with these slower resorbing graft materials A systematic review revealed no significant differences in the survival of implants placed simultaneous with grafting or after graft healing.14 There-fore, the decision to place dental implants simultaneous with the graft or after healing is largely determined by the ability to achieve primary stability in native bone

Sinus Grafting Techniques

When inadequate bone volume is present below the sinus for implant support, the sinus floor can be augmented Conven-tional radiographs, such as periapical and panoramic films, are useful for preliminary screening of potential implant sites

Cone beam computed tomography can better assess the able bone and further evaluate sinus health and morphology

avail-Cross-sectional images are useful to evaluate the ridge width, bone quality, and sinus floor The buccopalatal distance of the sinus can influence the amount of graft material needed for augmentation and healing time requirements.15 There are two surgical approaches that can be used to elevate the sinus mucosa and place graft material: the lateral window or direct sinus elevation and the transcrestal or indirect sinus floor elevation

These grafting techniques only address vertical bone ciencies The surgeon should also evaluate the residual ridge for facial bone loss and medial resorption following tooth loss

defi-This may necessitate concomitant horizontal bone tion for ideal implant placement In some cases, severe atrophy may also require vertical ridge augmentation (Fig 1-2)

augmenta-Lateral window approach

The lateral window approach is performed in the posterior maxilla by creating an osteotomy over the lateral sinus wall and leaving the sinus mucosa intact There have also been reports on using a palatal approach.16 The osteotomy may be created using rotary burs or piezoelectric tips to create an ovoid bone flap or complete removal of the overlying bone, providing an access opening for mucosal elevation This approach requires vertical releasing incisions with greater flap reflection and retraction than a transcrestal sinus floor elevation This greater surgical access can result in increased postoperative pain, facial swelling,

Fig 1-1 Clinical guidelines for managing the posterior maxilla based

on bone height below the sinus floor Overlapping colors indicate

that multiple options can be considered.

Standard implant Transcrestal lift + implant

Lateral window + bone graft + implant

Lateral window + bone graft

10 8 6 4 2 0

Sinus Grafting Techniques

and ecchymosis In addition, vessels within the lateral sinus wall

may be disrupted during preparation of the bony window,

caus-ing intraoperative bleedcaus-ing There may also be a greater risk of

sinus mucosa perforation using this approach compared with a

transcrestal elevation.17 However, open access allows for direct

repair of mucosal disruption Serious infections are rare but can

occur with this more invasive surgical approach

The main advantages of using a lateral window approach are

superior access, visibility of the mucosal elevation, and direct

access to the sinus floor This allows for placement of larger

volumes of graft material and greater vertical bone

augmenta-tion For this reason, it is the preferred technique for managing

the pneumatized sinus with minimal residual bone below the

sinus floor (0 to 5 mm) It would also be the preferred approach

if additional simultaneous horizontal or vertical ridge

augmenta-tion of the posterior maxilla were needed The posterior maxilla

resorbs medially following tooth loss, and this pattern of bone

loss may result in an unfavorable ridge relationship with the

opposing mandibular dentition If there is adequate residual

bone height, implants may be placed simultaneous with the

graft Otherwise, implants are placed after a period of graft

healing The lateral window technique may also be useful in

cases where sinus bone septa would complicate an internal

osteotome lift In this instance, two windows can be created

on each side of the septa and the sinus mucosa can be elevated

around and over the bony projection A lateral window approach

also allows for the removal of sinus pathology in conjunction

with sinus grafting

A systematic review on the lateral window sinus grafting

tech-nique including 59 articles and 13,162 implants found an overall

implant survival of 93.6% (range: 61.2% to 100%).18

Evidence-based reviews have concluded that rough-surfaced implants

have a significantly higher survival rate than machine-surfaced

implants in lateral window sinus grafts The use of a membrane

to cover the window over the graft may also have a positive

influ-ence on implant survival The use of a rough-surfaced implant

and membrane coverage over the graft was found to improve

implant survival to 98.6%.19 Chapters 6 and 8 have more

infor-mation on the lateral window technique

Transcrestal approach

The transcrestal approach for sinus augmentation involves creating an osteotomy through the ridge crest of the posterior maxilla This is usually done in conjunction with simulta-neous implant placement The osteotomy is typically prepared just short of the bony sinus floor The thin layer of remaining bone can be gently upfractured and elevated with an osteotome

or carefully reduced with a diamond bur or piezoelectric tip

Reverse-rotating osseodensification burs are another method

to create the transcrestal osteotomy without disrupting the sinus mucosa (see chapter 10) This indirect method requires less flap manipulation, so it is less invasive than the lateral window technique High patient satisfaction has been documented with this procedure.20

In cases where minimal additional bone height is needed for implant placement, it may not even be necessary to add graft material The space between the implant apex and sinus mucosa fills with blood clot that heals into bone (see chapter 7) Platelet concentrate, such as platelet-rich fibrin (PRF), can also be used

as a graft matrix The fibrin clot is introduced into the omy and compressed superiorly The matrix of fibrin, embedded with platelet and leukocyte cytokines, can act as a cushion to protect the sinus membrane and facilitate bone healing Larger amounts of bone augmentation can be achieved using partic-ulate bone graft materials.6 Osteoconductive bone substitutes, such as bovine bone mineral or mineralized bone allograft or alloplasts, can be hydrated with sterile saline and placed into the osteotomy The graft particles are gently compressed and elevated superiorly with an osteotome Some slight resistance should be noted when the particles are compacted upward

osteot-Larger graft particles (> 1.0 mm) with irregular or sharp etry are avoided because they may tear the sinus mucosa

geom-Grafting via the indirect method is less invasive but has the disadvantage that detection and management of sinus mucosa perforations is limited Disruption of the sinus mucosa can occur during drilling of the osteotomy, mucosal elevation, or graft and implant placement Although mucosal perforation is reported to be less frequent than with the lateral approach, the

Fig 1-2 (a) A bone scraper is used to collect particulate autograft and expose the sinus mucosa (b) Autogenous bone is placed along the sinus

floor and used for vertical ridge augmentation (c) Implants are placed 4 months after graft healing.

elevation of the sinus membrane should be regarded as

tech-nique sensitive.17 A small disc curette can be inserted into the

osteotomy to detect the sinus floor and assess the dissection of

the sinus membrane Valsalva maneuver has been used to test for

membrane perforation The presence of air bubbles appearing

through the osteotomy indicates a loss of mucosal integrity It

is difficult to blindly repair a sinus tear through the osteotomy

If a large perforation is encountered, the procedure may need to

be abandoned Another option is to create a lateral window for

better access to repair Benign paroxysmal positional vertigo has

been documented as an infrequent but unpleasant complication

of the osteotome technique.17

The transcrestal sinus floor elevation is typically used with

simultaneous implant placement and when less bone

augmen-tation is needed An endoscopic examination found the increase

in height by an osteotome technique alone should be limited to

approximately 3 mm.21 However, using the indirect approach,

bone gains between 3 and 9 mm have been reported.22 Greater

bone gains can be obtained by using graft material versus no

grafting Experienced surgeons proficient in the transcrestal

technique may manage cases with minimal available bone

Devices have also been developed to assist transcrestal

graft-ing usgraft-ing hydraulic pressure or a balloon catheter to elevate

the sinus mucosa.23 Although there is no definitive

measure-ment of residual bone to indicate one technique over the other,

improvements in the transcrestal method and a trend toward

using shorter implants have lessened the need for the lateral

approach.24 If the residual alveolar bone height is 6 mm, a

trans-crestal approach to elevate the sinus floor and place an 8-mm

implant may lead to fewer complications than using a lateral

window approach to place a longer implant

A systematic review on the transcrestal osteotome

tech-nique including 34 studies and 3,119 implants found an

over-all implant survival of 96.7%.25 The vast majority of implant

failures occurred early (< 1 year loading) Transcrestal sinus

floor elevation was most predictable when the residual alveolar

bone height was greater than 5 mm Shorter implants (< 8 mm)

demonstrated significantly lower cumulative survival rates than

longer implants.25 For more information on the transcrestal

approach, see chapter 9

Bone Graft Materials

In the first publication on the sinus bone graft technique in 1980,

Boyne and James26 used autogenous cancellous marrow from

the ilium Early Swedish studies on the reconstruction of the

atrophic maxilla used iliac bone grafts with machine-surfaced

implants.27 Autogenous bone was considered the gold standard of

graft materials for oral and maxillofacial reconstructive surgeries

In addition, there was a limited choice of bone substitutes and

a paucity of research on these alternative materials

Over time, clinicians began to evaluate the use of various

alternative bone materials for sinus augmentation Tricalcium

phosphate was the first bone substitute used for sinus bone grafting.28 In 1996, the Academy of Osseointegration held the Sinus Consensus Conference to evaluate retrospective data from clinicians The conference unanimously agreed that the sinus graft was an efficacious procedure.7 The overall implant survival rate was reported as 90% The various materials used for grafting all seemed to perform acceptably, and it was not possible to state with certainty that one material was better than another One limitation in evaluating the graft materials is that the residual bone below the sinus floor is often not reported Dental implant survival may be a function of residual native bone supporting the implant rather than grafted bone.29

Since the first consensus conference, numerous graft materials have been used for sinus augmentation The literature on sinus graft success is often evaluated by secondary outcomes, such as dental implant survival or histologic studies However, there are inherent limitations in using these secondary measurements

For example, machine-surfaced implants have lower survival

in grafted bone.18 A lower implant survival in a particular graft material could be interpreted as a poorer graft success In addi-tion, patients may suffer cluster implant failures due to factors unrelated to the graft material.30 Because of the variability in study design and numerous confounding variables, a direct comparison between published reports on graft materials is not possible This section evaluates studies on sinus grafting and discusses the use of different choices for graft materials

Autogenous bone

Literature review

The interpretation of the results with using autogenous bone for sinus grafting has been confusing and controversial Many clinicians have incorrectly concluded that the use of auto-graft is associated with a lower implant survival or that bone substitutes provide better results The 1996 Sinus Consensus Conference issued a consensus statement that autogenous bone is appropriate for sinus grafting.7 However, it was only

a majority opinion of the group that bone substitutes may be effective as a graft material in selected clinical situations A 2004 systematic review on sinus bone grafting by Del Fabbro et al14

concluded that bone substitutes are as effective as autogenous bone Four years later, the same group published an updated review with additional data.18 Although the results were essen-tially unchanged, they altered their opinion and stated that survival rates for implants in bone substitutes and composite grafts were slightly better than implants in 100% autogenous grafts However, in deriving this conclusion they combined the survival of both machine-surfaced and rough-surfaced implants in grafted sinuses Their data clearly showed that machine-surfaced implants had significantly lower implant survival rates and that the majority of sinuses grafted with auto-graft had machine-surfaced implants18 (Fig 1-3) Contrarily, sinuses grafted with bone substitutes only had rough-surfaced implants, casting doubt on their comparative conclusions

Bone Graft Materials

Pjetursson et al31 performed a systematic review that evaluated

bone grafting of pneumatized sinuses that had 6 mm or less

residual bone height When they focused on outcomes using

only rough-surfaced implants, they found high implant survival

rates (> 96%) for all types of grafts However, rough-surfaced

implants placed in particulate autogenous bone had a

signifi-cantly higher estimated 3-year survival (99.8%) Therefore, it

appears that the autogenous bone is not associated with a lower

implant survival, given that rough-surfaced implants

signifi-cantly improve outcome with sinus grafting This does not imply

that 100% autogenous bone is the preferred graft selection for

sinus augmentation; it merely clarifies the misconception that

it is an inferior material for use

Advantages and disadvantages

Autogenous bone has been considered the gold standard of graft

materials because it has superior biologic properties compared

with bone substitutes However, not all autogenous bone grafts

have osteogenic qualities Only viable bone-forming cells, found

mostly in the cancellous marrow, can directly produce new bone

Extraoral donor sites with a significant cancellous component,

such as the iliac crest or tibia, can provide this type of bone

quality Although intraoral donor sites are more convenient,

they do not contain many bone-forming cells The bone in the

maxillary tuberosity is porous, and the outer cortical layer is

thin The mandibular symphysis and ramus are mostly cortical

bone However, bone morphogenetic proteins (BMPs) found in

the cortical graft can recruit and induce mesenchymal stem cells

(MSCs) to become osteoblasts In addition, freshly harvested

cortical chips contain viable osteocytes capable of controlling

bone remodeling through a variety of additional growth factors

that induce gene expression in mesenchymal progenitor cells.32

The cortical portion of the autogenous bone graft also acts as an

osteoconductive scaffold for bone formation Local autogenous

bone can be easily harvested from the tuberosity or collected

from a bone-scraping device passed over the lateral maxilla and

zygomatic buttress

If additional autograft is desired, bone can be harvested from

the mandibular body and ramus area with a scraping device or

collection bur Rarely would it be necessary to harvest bone

from the mandibular symphysis, tibia, or ilium for

straight-forward sinus grafting because these sites can add morbidity

If the severely atrophic maxilla is reconstructed with an iliac

bone graft, then cancellous bone may also be used for the sinus

However, mixing the particulate cancellous autograft with a

slow-resorbing bone substitute, such as bovine bone mineral,

should be considered to help maintain graft volume during

healing.33 Some loss of augmentation volume always occurs

after sinus grafting during early healing times In general,

less volume loss can be expected with bone substitutes than

with 100% autogenous bone.33 However, the remodeling of an

autogenous graft stabilizes, and the reduced volume does not

seem to compromise implant placement or survival.33 The use

of a barrier membrane over the sinus window has also been

advocated when bone substitutes are used.34 Instead of using a

commercially produced membrane, a thin piece of cortical bone obtained from the tuberosity area can be used as an autologous barrier to cover the window35 (Fig 1-4)

There are potential advantages in using autogenous bone

in sinus grafts, especially when the sinus cavity is large and minimal bone remains below the sinus floor.36,37 The supe-rior biologic properties of autogenous bone grafts can result

in greater bone formation at earlier time periods than bone substitutes.38 Several studies have found an increase in bone formation when autogenous bone is used alone or added to other grafting materials in sinus grafts.39–43 Based on a review

of histomorphometric studies, autogenous bone was found to result in the highest amount of new bone formation in compar-ison with the other sinus graft materials.12 There is conflicting evidence on improving bone formation with mixing a small amount of autograft and bovine bone mineral.40,44 A small volume of autogenous bone may not be biologically available when it is mixed within a large amount of bone substitute A better strategy may be to layer the graft materials within the sinus.45 The bone substitute can be inserted first and elevated superiorly so the particulate autogenous bone can be placed along the sinus floor (Fig 1-5) This provides the autograft with

a better environment for healing and bioavailability in close approximation to the native bone

Compared with bone substitutes, the healing time ments of autogenous bone grafts are shorter, especially in larger pneumatized sinuses.15 The healing period for sinuses grafted with 100% autogenous bone can be as short as 3 to 4 months compared with the 8 to 10 months often recommended for bone substitutes.40,46 The addition of autogenous bone to composite bone grafts may also shorten healing times and influence bone remodeling patterns.40,47,48 This offers a potential advantage because patients often object to extended treatment lengths.49

require-Not only do autogenous bone grafts heal faster than bone tutes; the biology of the regenerated bone may be improved

substi-Machine-surfaced implants Rough-surfaced implants

100 95 90 85 80

96.7%

Autogenous Combined Substitutes

Histologic studies have shown greater bone formation and

higher bone-to-implant contact when autogenous bone grafts

are used compared with allografts.42 This improved bone

forma-tion at an earlier time can allow for shorter implant healing

periods than with the use of bone substitutes alone

The main disadvantage in using large amounts of

autoge-nous bone for sinus floor grafting is the potential for

compli-cations from bone harvest Local intraoral donor sites, such as

the maxillary tuberosity and zygomatic buttress, incur

mini-mal added morbidity The mandibular body and ramus have a

low incidence of complications, but a secondary surgical site

is required.50 The mandibular symphysis and extraoral sites,

such as the tibia or iliac crest, can significantly increase surgical

risks and morbidity The harvest of autogenous bone requires

added surgical time and may require sedation Iliac bone harvest

requires an operating room and general anesthesia Although

using autogenous bone decreases graft material costs for the

surgeon, it may be necessary to purchase equipment or

instru-mentation for bone harvest

Bone substitutes

There have been several evidence-based reviews evaluating ous graft materials for sinus bone augmentation They have essentially concluded that bone substitutes are as effective as autogenous bone for sinus grafting As previously discussed, sinus bone graft success is often measured by a secondary outcome, such as the amount of vital bone formation There are inherent limitations in using this measurement to evaluate graft success Clinical studies have failed to identify the defined minimal amount of vital bone needed for implant integration and survival.12 Histomorphometric studies have shown a wide range of vital bone formation For example, xenografts produce approximately 25% of vital bone formation by volume at 8 months healing.19 Although bone substitutes are associated with

vari-a lower percentvari-age of vitvari-al bone thvari-an vari-autogrvari-afts, their implvari-ant survival rates are similar.51

The obvious advantages of using bone substitutes are decreased morbidity and shorter surgical time They are also available as a sterile, uniform product in an unlimited supply

It is not feasible to review every bone substitute used as a graft

Fig 1-5 (a) Bovine bone mineral is placed

first and elevated superiorly as the first layer

(b) Mineralized bone allograft is used as the second layer (c) Autogenous bone from the

ramus and tuberosity is placed along the sinus

floor and over the window (d) Sinus and block

bone graft after 4 months of healing.

Bone Graft Materials

material for sinus augmentation, nor is it possible to

deter-mine which bone replacement material provides the best results

There is a lack of randomized controlled clinical trials with

suffi-cient statistical power comparing various grafting materials.19 In

addition, there are too many confounding variables to account

for in comparing materials In some studies, graft products

have even been combined Furthermore, a lower percentage of

the implants evaluated in systematic reviews on sinus grafting

were placed in bone substitutes alone.18 In general, the implant

survival rates are high with several types of bone replacement

grafts with negligible differences

An ideal bone substitute for sinus grafting would fulfill several

criteria, as follows:

• Particulate graft materials are much easier to use in sinus

augmentation than block forms

• The graft should provide a biocompatible osteoconductive

scaffold for new bone formation

• The product should be well documented with supportive

clinical studies

• The graft should have favorable handling characteristics with

a particle size and geometry that provides adequate space for

revascularization and bone ingrowth

• The particles should not be too large or irregular in shape

because this could risk sinus membrane disruption

• A radiopaque graft material makes it easier to identify on

postoperative radiographs

• A slower resorbing material will provide a stable scaffold for

bone formation and maintain graft volume during healing

• A low to moderate cost would also be preferred

There are several graft products in all bone substitute

cate-gories (allograft, xenograft, alloplast) that satisfy the proposed

criteria Although some clinicians prefer to combine different

bone substitutes, there is no evidence to support the benefits

of this practice, and the use of one material simplifies

inven-tory and surgery

Xenografts

Anorganic bovine bone mineral has been studied extensively

and has the most clinical documentation for sinus grafting

This xenograft product has demonstrated very favorable clinical

outcomes and high implant survival rates.19 It is a deproteinized,

bovine cancellous product with a native crystalline structure

that is very similar to human bone Bovine bone mineral is a

highly biocompatible and osteoconductive material that allows

for deposition of vital bone directly on the surface of the

xeno-graft particles As such, the particles become integrated into the

bone matrix and natural physiologic remodeling process This

provides added mineral density to the graft for dental implant

placement and stability.19 Although one study suggested that a

larger particle size may allow more bone ingrowth, another

clin-ical evaluation found no difference between larger and smaller

particle xenografts.52,53 Histologic evidence has shown that the

xenograft particles do not interfere with the development of the

bone-to-implant interface.54 The slow-resorbing nature of bovine bone mineral maintains graft height and provides long-term volume preservation There has been some concern raised regarding the possible risk of bovine spongiform encepha-lopathy from a xenograft product To date, there has not been any reported case of disease transmission from bovine bone mineral This risk can be essentially eliminated by stringent safety requirements by the manufacturer, chemical and physi-cal purification of the product, and sterilization procedures.55

Allografts

Although allograft bone substitutes are popular in the United States, many countries strictly regulate or prohibit their use in patient treatment The main concerns associated with these materials are possible antigenicity and risk of disease trans-mission from donor to recipient However, accredited tissue banks have essentially negated this risk through stringent donor screening, tissue recovery, and disinfection processes.56 Demin-eralized freeze-dried bone allografts may have limitations for sinus bone grafting This material is not radiodense and can be more difficult to identify on postoperative films Used alone in

a pneumatized sinus, a demineralized graft has poor scaffolding properties and may be subject to loss of height during healing

Although it may contain some BMPs, the amounts are so cule that the clinical significance of its osteoinductive capacity has been questioned.57 Demineralized freeze-dried bone has also been found to provide lower implant survival rates than other bone substitutes.7,58 There is a clinical trend toward using mineralized bone allografts These materials are radiopaque and provide better osteoconductive scaffolding for bone ingrowth and maintenance The particulate mineralized products come

minis-in cortical, cancellous, and mixtures of these two forms They have a faster turnover and more physiologic resorption profile than slower resorbing bovine bone mineral.59 A blind random-ized controlled study on bovine bone mineral and mineralized bone allograft used for sinus grafting found that significantly more vital bone was formed in the allograft sites at 26 to 32 weeks healing (28% vs 12%).60 Another prospective randomized split-mouth study comparing a biphasic calcium phosphate alloplastic bone substitute with mineral allograft found at 9 months healing that the allograft had a higher osteoconductive value and less residual graft material.61

Alloplasts

There are numerous different types of alloplastic materials that have been successfully used for sinus bone grafting, including hydroxyapatite, calcium sulfate, calcium phosphate, bioactive glass, titanium granules, and polymers.62 These materials are synthetically produced or derived from natural materials and processed Tricalcium phosphate was the first bone substi-tute used for sinus bone grafting.28 Early experience was also reported on use of a dense nonresorbable hydroxlapatite.63

Because these graft materials are synthetic, there is no risk of disease transmission They have osteoconductive properties that provide scaffolding for new bone ingrowth and/or replacement

They are available in resorbable and nonresorbable forms with

various particle sizes, geometries, pore sizes, and porosity levels

An important factor to consider for sinus grafting is the rate of

degradation for maintenance of vertical height Much like

xeno-grafts, porous hydroxyapatite has been mixed with particulate

autogenous bone to better maintain graft volume Alloplastic

materials may be quite useful in the future because they may

be customized for cellular constructs and delivery of growth

factors

No graft

The basic principles of bone regeneration require space

main-tenance for bone ingrowth and stability of the wound for blood

clot formation and subsequent healing.64 In 2004, Lundgren et

al65 published on a lateral window technique where the sinus

mucosa was elevated for implant placement but no bone graft

material was inserted The implant apices supported the sinus

mucosa, and a blood clot was allowed to form around the

implants Thereafter, the bone window was replaced All of

the implants integrated, and computed tomography showed

new bone formation However, the researchers noted that the

bone levels peaked around the implants and did not cover the

apices Several subsequent studies have found that nongrafted

sinus floor elevation using the lateral window and transcrestal

approach seems to be characterized by new bone formation and

high implant survival rates comparable to grafted sinus floor

augmentation.66 The vast majority of implant failures with this

technique are early during healing.25 Long-term comparative

studies of no grafting versus grafting are lacking, so conclusions

should be interpreted with caution

Membranes

During early development of the lateral window technique, graft

material was placed along the sinus floor and the

mucoperi-osteal flap was repositioned and closed over the grafted site.67

Later on, the placement of a barrier membrane over the graft to

cover the sinus window was proposed.68 It was theorized that a

barrier membrane could prevent soft tissue cells from growing

into the graft and facilitate the growth of bone tissue within

the sinus This was observed in one study in which biopsies

were taken after 6 months of healing using mineralized bone

allografts with or without expanded polytetrafluoroethylene

(ePTFE) membranes over the window Sinus grafts without the

membrane had greater scarring and soft tissue.68 A follow-up

study evaluated 12 patients undergoing bilateral sinus grafts

and found that sinus grafts covered with ePTFE membrane

had increased vital bone formation and had a positive effect on

implant survival.34 The conclusion was that membrane

place-ment should be considered for all sinus elevation procedures

However, there is conflicting evidence regarding routine use

of a barrier membrane over a sinus graft, and the use of ePTFE

led to a high rate of infection Some systematic reviews support

the idea that dental implant survival rates can be improved if a

membrane is placed over the sinus window.69 However, another review indicated that there was insufficient evidence on the effects of membranes to make definitive conclusions due to limited sample sizes, short follow-up periods, and a high risk

of bias.70 A meta-analysis of 37 studies on the effect of using a barrier membrane on the histomorphometric outcomes of sinus augmentation determined that a membrane did not influence the amount of new vital bone formation.71 A randomized clin-ical trial comparing maxillary sinus augmentation with and without a membrane over the window found that the use of the membrane did not substantially increase the amount of vital bone over a period of 6 months.72 However, the use of a membrane did seem to reduce the proliferation of the connec-tive tissue and the graft resorption rate Similar findings were reported in a split-mouth prospective pilot study on bovine bone mineral sinus grafts.73 Another randomized clinical trial with a two-arm and split-mouth design comparing sinus grafts with and without membranes found that implant survival was not influenced by membrane coverage.74

There may be several factors that explain the different ings on this topic As previously mentioned, there are many variations in study design and numerous confounding variables that do not allow direct comparison between published reports

find-For example, one study reported that a collagen barrier used

to cover the window improved the survival rate of machine- surfaced implants in sinus grafts using bovine bone mineral.75

Using a rough-surfaced implant improves survival, and this may override the influence of a membrane There is also a lack

of studies differentiating the type of graft material used with membrane coverage Osteoconductive bone substitutes may benefit from membrane coverage more than 100% autogenous bone would When no bone graft is used, the access window

is typically replaced to protect the clot Sinuses grafted with recombinant human BMP-2 (rhBMP-2) and absorbable collagen sponge (ACS) are not covered with a barrier membrane to allow unimpeded chemotaxis, cell migration, and vascular ingrowth

Another factor that many impact this decision is the amount of bone below the sinus floor and size of the sinus cavity It may

be more beneficial to use a membrane when the sinus is wider

or there is minimal residual bone The size of the sinus access opening could also influence this decision Smaller windows that maintain more bone to encase the graft have been shown to have a positive correlation with the maturation and consolida-tion of the bone graft76 (Fig 1-6) Incorporation of a sinus graft material may improve from placement of a barrier membrane over a larger window The research does not support the opin-ion that routine membrane coverage of the lateral window is necessary in every case The disadvantage is added cost if a commercial membrane is used

When coverage of the window was originally proposed, nonresorbable PTFE membranes were used.68 This type of membrane requires stabilization over the lateral maxilla with tacks or screws to prevent micromovement Exposure of PTFE membranes is a potential problem that can negatively affect the result A resorbable membrane has advantages because it

Bone Graft Materials

does not require fixation and subsequent removal.68

Resorb-able collagen membranes used for guided bone regeneration

are well suited for this purpose Another option is to harvest

a thin piece of cortical bone as a natural resorbable barrier to

cover the antrostomy Some authors advocate replacement of

the lateral window itself (see chapter 7) After performing the

peripheral osteotomy to create the window, the piece of bone is

removed intact and then repositioned over the grafted sinus.77 As

discussed previously, another option is to procure a thin cortical

graft from the tuberosity area and shape it to cover the window.35

Some clinicians have suggested using PRF over the window

However, a fibrin membrane is not a cell occlusive barrier, and

there is no evidence this improves sinus graft healing

Bioactive products

Evidence-based reviews reveal that dental implant survival in

grafted sinuses is very high and equal to or better than implants

placed in native maxillary bone.19 As such, there is no

signif-icant margin for improvement in implant survival rates using

new graft materials or bioactive products In addition, studies

have found that high implant survival rates can be obtained

using bone substitutes that produce relatively low amounts

of new vital bone.19 Therefore, a new strategy to improve vital

bone formation using tissue-engineering products, such as

cell-based therapies or signaling molecules, would also not

necessar-ily improve outcomes Future research on sinus bone grafting

should therefore focus on shortening treatment duration by

reducing the time needed for graft maturation and/or implant

healing as well as minimizing patient morbidity Although the

use of autogenous bone for sinus grafting may accelerate new

bone formation when compared with bone substitutes, the

added morbidity from bone harvest is undesirable The search

for bioactive products that can decrease sinus graft healing time

and minimize patient morbidity should be the goal of future

clinical research

Platelet concentrates

Platelet concentrates are prepared following blood draw using

a centrifuge device There are various protocols that produce

different forms of platelet-rich preparations The platelets

contain numerous growth factors that stimulate and accelerate

the tissue-repair process Platelet concentrates have been used with bone substitutes for sinus bone grafting in an attempt to enhance bone regeneration However, a number of systematic reviews have failed to provide evidence that platelet concentrates increase or accelerate new bone formation.78–81 Some researchers have claimed that newer generations of platelet-rich prepara-tions (ie, PRF) contain different cell compositions and greater amounts of cytokines with better release kinetics However, these formulations have also not shown any significant improve-ments when added to bone substitutes in sinus grafts.82–85 One randomized clinical trial did find that using a platelet concen-trate with sinus bone augmentation resulted in significantly less pain, less swelling, and improved functional activities when compared with the control group.86 A clinical benefit of platelet- rich preparations is improved handling and containment of bone graft particles within the fibrin clot The fibrin matrix has also been proposed as an autogenous membrane for the repair

of sinus mucosa perforations.87

Some clinicians have advocated using PRF as the sole material for sinus grafting PRF consists of an autogenous leukocyte- and platelet-rich fibrin matrix containing cytokines and stem cells A limited number of studies have shown favorable vertical bone gains and implant survival using both the lateral window and osteotome approaches for simultaneous implant placement with PRF.88,89 The fibrin clot may also serve as a cushion against the sinus mucosa over the implant apex However, there is

no evidence that PRF accelerates bone formation or produces better outcomes than a blood clot alone or other graft materials

rhBMP

BMPs are a group of growth factors that are chemotactic for MSCs and induce their differentiation into osteoblasts Recom-binant technology has produced proteins that can mimic this activity for bone regeneration in various clinical applications

The most actively studied of these cytokines is rhBMP-2 One issue with rhBMP-2 is that it is rapidly degraded by proteases,

so larger amounts of the protein are required to initiate bone formation The recombinant protein is packaged with an ACS as the carrier to release the growth factor into the site The use of rhBMP-2/ACS for sinus bone grafting has been thoroughly inves-tigated in two large randomized controlled clinical trials.90,91

Both studies compared outcomes between rhBMP-2/ACS and autogenous bone and concluded that dental implants placed in

Fig 1-6 (a) The sinus window opening is

limit-ed to maintain the bone walls (b) The limitlimit-ed

sinus access is wide enough to introduce a

bone graft syringe.

rhBMP-2/ACS and autogenous bone graft groups performed

similarly after functional loading (Fig 1-7)

The use of rhBMP-2/ACS for sinus bone grafting has several

disadvantages Although the ACS has been found to be an

opti-mal carrier for the rhBMP-2 molecule, it has poor scaffolding

properties As such, the collagen mass loses significant volume

during healing when used for sinus augmentation In addition,

the collagen is not radiodense, so it is more difficult to identify

on postoperative radiographs until bone mineralization has

occurred A large volume of this material is needed for sinus

augmentation The growth factor is very expensive and may be

considered cost-prohibitive considering more economic graft

products perform just as well In the sinus bone graft study by

Boyne et al,90 the rhBMP-2/ACS grafts had significantly less

radiographic bone density than autograft sites at 4 months of

healing This difference is likely due to the mechanism of bone

formation The de novo bone formation by rhBMP-2 requires

greater time for healing and mineralization As such, the bone

quality at implant placement may be less dense than

mineral-ized bone grafts The use of rhBMP-2 is associated with

signif-icant edema that compromises the postoperative experience

for the patient The swelling is unavoidable and is not reduced

by measures such as steroid therapy and ice packs The dental

implant survival for rhBMP-2/ACS sinus grafts in two

random-ized controlled clinical trials was rather low (76% and 83%).90,91

When using rhBMP-2 for sinus grafting, the inclusion of a

particulate mineralized graft material has been suggested to

reduce volume loss from the collagen sponge Adding graft

material would also decrease the cost because less growth factor

would be needed Froum et al92 compared sinuses grafted with

mineralized bone allograft alone and two different

concentra-tions of rhBMP-2 (8.4 mg and 4.2 mg) mixed with mineralized

bone allograft All three groups had similar bone volume and

graft shrinkage Density measurements showed that allograft

alone had statistically significant greater density at selected time

points The histologic results after 6 to 9 months of healing

showed no statistically significant differences in the amount

of vital bone between the two test groups compared with the

control sinus group treated with allograft alone It was also

noted that the growth factor accelerated resorption of the mineralized allograft particles Another study comparing bone formation using bovine bone mineral with rhBMP-2 and bovine bone mineral alone found that the growth factor actually had

a negative effect of bone formation A pilot study comparing sinus augmentation with rhBMP-7 and bovine bone mineral versus bovine bone mineral alone found significantly less new bone formation in the rhBMP-7 grafts.93 In contrast, a compari-son study of a different form of rhBMP-2, low-dose Escherichia coli–derived, showed an improved outcome (see chapter 23).94

This cytokine was not bound to a collagen sponge but was soaked with hydroxyapatite granules Core biopsies obtained

at 3 months found significantly more new bone formation with the low-dose BMP sinus grafts than bovine bone mineral alone (16.10% vs 8.25%) Although the use of rhBMP-2/ACS has been shown to induce bone formation in the sinus, it does not shorten healing time and increases postoperative morbidity with significantly higher costs Other recombinant BMPs may prove to offer benefits in the future, but additional research is needed at this time

rhPDGF

Platelet-derived growth factor (PDGF) is a wound healing cytokine found in the α granules of platelets It regulates cell mitosis and the formation of new blood vessels The protein is chemotactic for MSCs, fibroblasts, and osteoblasts and enhances cell proliferation A recombinant form of this growth factor (rhPDGF-BB) was approved for use in periodontal regenera-tion Off-label use of rhPDGF-BB in sinus bone grafting has been evaluated in two studies.95,96 Froum et al95 assessed vital bone formation at 4 to 5 months and 7 to 9 months following sinus augmentation with bovine bone mineral with and with-out rhPDGF-BB Vital bone formation was significantly greater

in the earlier specimens containing rhPDGF-BB At the later time period in 7 to 9 months, this difference had disappeared

In another study, Kubota et al96 treated 46 patients with sinus augmentation using bovine bone mineral and rhPDGF-BB The residual bone below the sinus measured only 0.77 ± 0.28 mm

Implants were placed after 4 months of healing with able primary stability measurements at placement and after 8 weeks for a survival of 100% These two clinical studies suggest that more rapid formation of vital bone with the addition of rhPDGF-BB may allow for earlier implant placement However, additional research is needed to support this premise

favor-Stem cells

Stem cells are undifferentiated with a capacity to differentiate into specialized cell lines when exposed to specific stimuli Adult stem cells may be harvested from bone marrow, periosteum, adipose tissue, blood, and dental pulp The number and concen-tration of transplanted stem cells are critical factors in producing

a favorable clinical result Bone marrow aspirates (BMA) from the ilium are a rich source of MSCs for bone regeneration A centrifuge device can be used to concentrate the collected cells from the BMA The stems cell may also be harvested, cultured,

Fig 1-7 After a zygomatic implant failed, rhBMP-2/ACS

was used to repair the bone defect.

References

and expanded in the laboratory The MSCs are usually seeded

onto some type of scaffold that guides their growth and

prolif-eration Bone substitutes, such as bovine bone mineral or

trical-cium phosphate, are often used as the scaffold for sinus grafting

There are several case series studies showing that the use of

MSCs is clinically feasible for sinus bone grafting in preparation

for implant placement.97–99 However, comparison studies with

autogenous bone or autograft/bone substitute mixtures do not

show superior histologic or clinical outcomes A split-mouth

study found no significant difference in new bone formation

between the bone graft mineral with BMA and a control group

with bone graft mineral alone.100 Another study compared

bovine bone mineral with BMA and 100% autogenous bone

for sinus augmentation Dental implants were placed 4 months

after graft healing Although the stem cell grafts compared

favor-ably with the autograft sites, the dental implant survival was

lower (91% vs 100%).101 A clinical study comparing histologic

results between bovine bone mineral mixed with either BMA or

30% autogenous bone found low new bone formation (< 15%)

at 4 months and no significant difference between groups.102 A

prospective controlled clinical trial evaluated new bone

forma-tion between sinuses grafted with bovine bone mineral mixed

with BMA or autogenous bone harvested from the mandible

Biopsies taken at 14 weeks did find more new bone in the

BMA grafts (17.7%) than sinuses with autograft (12%).103 One

sinus graft study evaluated the use of cryogenically preserved

allogeneic stem cells from cadavers.104 The authors compared

allogeneic MSCs with mineralized bone allograft and

miner-alized bone allograft alone Histologic cores taken at 3 to 4

months found significantly more vital bone formation with the

allogeneic MSCs (32.5% vs 18.3%)

This technique is not without challenges, however The

allo-geneic MSCs must be shipped frozen and thawed before use

within 4 hours There is also a concern for possible disease

transmission and the number of viable cells that survive harvest

and processing It appears that the use of MSCs may produce

outcomes similar to autogenous bone grafts Further clinical

trials are needed to evaluate the potential benefits of MSCs in

sinus grafting However, the evidence that the sinus graft healing

time is significantly reduced is not compelling considering the

morbidity of cell harvest, additional surgical time, and added

material costs

Conclusion

The sinus bone graft has proven to be one of the most predictable

bone augmentation methods for dental implant placement and

support The decision to place dental implants simultaneous

with a graft or after healing is largely determined by the

abil-ity to achieve primary stabilabil-ity in native bone When minimal

bone is present below the sinus floor, a lateral window provides

superior access for mucosal elevation and placement of graft

materials for greater vertical bone augmentation The crestal approach is more often used when modest augmenta tion

trans-is needed in conjunction with simultaneous implant placement

The need for significant vertical bone augmentation in the posterior maxilla has been challenged by successful outcomes with shorter implants In addition, the use of tilted and zygo-matic implants may avoid the need to perform bone grafting procedures

There is currently sparse evidence that bioactive products can significantly decrease sinus graft healing time Platelet concen-trates can improve graft handling and containment, but they

do not improve bone graft healing Studies on rhBMP-2/ACS show that a longer time period is needed for bone maturation, and this product adds morbidity and significant cost Additional clinical research is needed on rhPDGF-BB to validate that this growth factor may allow for earlier implant placement Although MSC therapy may produce bone amounts similar to autogenous bone, a higher percentage of vital bone will not necessarily improve implant outcomes The use of autogenous stem cells also adds morbidity, costs, and surgical time Future research may find growth factors, cellular constructs, and/or scaffolds that enhance outcomes with sinus bone grafting Clinicians will need to weigh the higher costs of these options against the possibility for an enhanced biologic response and potential for minimizing patient morbidity

References

1 Jaffin RA, Berman CL The excessive loss of Branemark fixtures

in type IV bone: A 5-year analysis J Periodontol 1991;62:2–4.

2 Misch CE Treatment planning for edentulous maxilla posterior region In: Misch CE Contemporary Implant Dentistry, ed 3 St Louis: Mosby Elsevier, 2008:389–405.

3 Thoma DS, Zeltner M, Hüsler J, Hämmerle CH, Jung RE EAO Supplement Working Group 4—EAO CC 2015 Short implants versus sinus lifting with longer implants to restore the posterior maxilla: A systematic review Clin Oral Implants Res 2015;26 (suppl 11):154–169.

4 Khouly I, Veitz-Keenan A Insufficient evidence for sinus lifts over short implants for dental implant rehabilitation Evid Based Dent 2015;16:21–22.

5 Atieh MA, Zadeh H, Stanford CM, Cooper LF Survival of short dental implants for treatment of posterior partial edentulism: A systematic review Int J Oral Maxillofac Implants 2012;27:1323–

8 Peleg M, Garg A, Mazor Z Predictability of simultaneous implant placement in the severely atrophic posterior maxilla: A 9-year longitudinal experience study of 2132 implants placed into 731 human sinus grafts Int J Oral Maxillofac Implants 2006;21:94–102.

9 Khoury F Augmentation of the sinus floor with mandibular bone

block and simultaneous implantation Int J Oral Maxillofac

Im-plants 1999;14:557–564.

10 Chiapasco M, Felisati G, Maccari A, Borloni R, Gatti F, Di Leo F

The management of complications following displacement of

oral implants in the paranasal sinuses: A multicenter clinical report

and proposed treatment protocols Int Oral Maxillofac Surg

2009;38:1273–1278.

11 Bortoluzzi MC, Manfro R, Fabris V, Cecconello R, Derech ED

Comparative study of immediately inserted dental implants in

sinus lift: 24 months of follow-up Ann Maxillofac Surg 2014;4:

30–33

12 Danesh-Sani SA, Engebretson SP, Janal MN Histomorphometric

results of different grafting materials and effect of healing time

on bone maturation after sinus floor augmentation: A

systemat-ic review and meta-analysis J Periodontal Res 2017;52:301–312

13 Wang F, Zhou W, Monje A, Huang W, Wang Y, Wu Y Influence

of healing period upon bone turn over on maxillary sinus floor

augmentation grafted solely with deproteinized bovine bone

mineral: A prospective human histological and clinical trial Clin

Implant Dent Relat Res 2017;19:341–350

14 Del Fabbro M, Testori T, Francetti L, Weinstein R Systematic

review of survival rates for implants placed in the grafted

maxil-lary sinus Int J Periodontics Restorative Dent 2004;24:565–577.

15 Avila G, Wang HL, Galindo-Moreno P, et al The influence of the

bucco-palatal distance on sinus augmentation outcomes J

Peri-odontol 2010;81:1041–1050

16 Stübinger S, Saldamli B, Seitz O, Sader R, Landes CA Palatal

versus vestibular piezoelectric window osteotomy for maxillary

sinus elevation: A comparative clinical study of two surgical

tech-niques Oral Surg Oral Med Oral Pathol Oral Radiol Endod

2009;5:648–655.

17 Del Fabbro M, Corbella S, Weinstein T, Ceresoli V, Taschieri S

Implant survival rates after osteotome-mediated maxillary sinus

augmentation: A systematic review Clin Implant Dent Relat Res

2012;14:e159–e168.

18 Del Fabbro M, Rosano G, Taschieri S Implant survival rates after

maxillary sinus augmentation Eur J Oral Sci 2008;116:497–506.

19 Wallace SS, Tarnow DP, Froum SJ, et al Maxillary sinus elevation

by lateral window approach: Evolution of technology and

tech-nique J Evid Based Dent Pract 2012;12(3 suppl):161–171.

20 Pjetursson BE, Rast C, Bragger U, Schmidlin K, Zwahlen M, Lang

NP Maxillary sinus floor elevation using the (transalveolar)

os-teotome technique with or without grafting material Part I:

Im-plant survival and patients’ perception Clin Oral ImIm-plants Res

2009;20:667–676.

21 Nkenke E, Schlegel A, Schultze-Mosgau S, Neukam FW, Wiltfang

J The endoscopically controlled osteotome sinus floor elevation:

A preliminary prospective study Int J Oral Maxillofac Implants

2002;17:557–566.

22 Al-Dajani M Recent trends in sinus lift surgery and their clinical

implications Clin Implant Dent Relat Res 2016;18:204–212

23 Kfir E, Kfir V, Eliav E, Kaluski E Minimally invasive antral membrane

balloon elevation: Report of 36 procedures J Periodontol

2007;78:2032–2035.

24 Block MS Improvements in the crestal osteotome approach have

decreased the need for the lateral window approach to augment

the maxilla J Oral Maxillofac Surg 2016;74:2169–2181.

25 Shi JY, Gu YX, Zhuang LF, Lai HC Survival of implants using the

osteotome technique with or without grafting in the posterior

maxilla: A systematic review Int J Oral Maxillofac Implants

28 Tatum H Jr Maxillary and sinus implant reconstructions Dent Clin North Am 1986;30:207–229.

29 Aghaloo TL, Moy PK Which hard tissue augmentation techniques are the most successful in furnishing bony support for implant placement? Int J Oral Maxillofac Implants 2007;22(suppl):49–70.

30 Chrcanovic BR, Kisch J, Albrektsson T, Wennerberg A Analysis

of risk factors for cluster behavior of dental implant failures Clin Implant Dent Relat Res 2017;19:632–642

31 Pjetursson BE, Tan WC, Zwahlen M, Lang NP A systematic review

of the success of sinus floor elevation and survival of implants inserted in combination with sinus floor elevation J Clin Peri- odontol 2008;35(8 suppl):216–240.

32 Caballé-Serrano J, Bosshardt DD, Buser D, Gruber R

Proteom-ic analysis of porcine bone-conditioned medium Int J Oral illofac Implants 2014;29:1208–1215

Max-33 Shanbhag S, Shanbhag V, Stavropoulos A Volume changes of maxillary sinus augmentations over time: A systematic review

Int J Oral Maxillofac Implants 2014;29:881–892.

34 Tarnow DP, Wallace SS, Froum SJ, Rohrer MD, Cho SC logic and clinical comparison of bilateral sinus floor elevations with and without barrier membrane placement in 12 patients:

Histo-Part 3 of an ongoing prospective study Int J Periodontics storative Dent 2000;20:117–125.

Re-35 Misch CM Autogenous bone grafting for dental implants In:

Fonseca RJ, Marciani RD, Turvey TA (eds) Oral and Maxillofacial Surgery, ed 2 St Louis: Elsevier, 2009:406–427.

36 Jang HY, Kim HC, Lee SC, Lee JY Choice of graft material in relation to maxillary sinus width in internal sinus floor augmen- tation J Oral Maxillofac Surg 2010;68:1859–1868.

37 Zinser MJ, Randelzhofer P, Kuiper L, Zöller JE, De Lange GL The predictors of implant failure after maxillary sinus floor augmen- tation and reconstruction: A retrospective study of 1045 consec- utive implants Oral Surg Oral Med Oral Pathol Oral Radiol 2013;115:571–582

38 Jensen SS, Broggini N, Hjørting-Hansen E, Schenk R, Buser D

Bone healing and graft resorption of autograft, anorganic bovine bone and beta-tricalcium phosphate A histologic and histomor- phometric study in the mandibles of minipigs Clin Oral Implants Res 2006;17:237–243.

39 Block MS, Kent JN Sinus augmentation for dental implants: The use of autogenous bone J Oral Maxillofac Surg 1997;55:1281–

1286.

40 Froum SJ, Tarnow DP, Wallace SS, Rohrer MD, Cho SC Sinus floor elevation using anorganic bovine bone matrix (OsteoGraf/N) with and without autogenous bone: A clinical, histologic, radio- graphic, and histomorphometric analysis—Part 2 of an ongoing prospective study Int J Periodontics Restorative Dent 1998;

18:528–543.

41 Lorenzetti M, Mozzati M, Campanino PP, Valente G Bone mentation of the inferior floor of the maxillary sinus with autoge- nous bone or composite bone grafts: A histologic-histomorpho- metric preliminary report Int J Oral Maxillofac Implants 1998;

aug-13:69–76.

42 Jensen OT, Sennerby L Histological analysis of clinically retrieved titanium microimplants placed in conjunction with maxillary sinus floor augmentation Int J Oral Maxillofac Implants 1998;13:513–

521.

References

43 Schmitt CM, Doering H, Schmidt T, Lutz R, Neukam FW, Schlegel

KA Histological results after maxillary sinus augmentation with Straumann Bone Ceramic, Bio-Oss, Puros, and autologous bone

A randomized controlled clinical trial Clin Oral Implants Res 2013;24:576–585

44 Jensen T, Schou S, Stavropoulos A, Terheyden H, Holmstrup P

Maxillary sinus floor augmentation with Bio-Oss or Bio-Oss mixed with autogenous bone as graft: A systematic review Clin Oral Implants Res 2012;23:263–273.

45 Khoury F, Keller P, Keeve PL Stability of grafted implant

place-ment sites after sinus floor elevation using a layering technique:

10-year clinical and radiographic results Int J Oral Maxillofac Implants 2017;32:1086–1096

46 Soardi CM, Spinato S, Zaffe D, Wang HL Atrophic maxillary floor

augmentation by mineralized human bone allograft in sinuses

of different size: A histologic and histomorphometric analysis

Clin Oral Implants Res 2011;22:560–566

47 Hallman M, Sennerby L, Lundgren S A clinical and histologic

evaluation of implant integration in the posterior maxilla after sinus floor augmentation with autogenous bone, bovine hydrox- ylapatite, or a 20:80 mixture Int J Oral Maxillofac Implants 2002;173:635–643.

48 Galindo-Moreno P, Moreno-Riestra I, Avila G, et al Effect of

anor-ganic bovine bone to autogenous cortical bone ratio upon bone remodeling patterns following maxillary sinus augmentation Clin Oral Implants Res 2011;22:857–864.

49 Handschel J, Simonowska M, Naujoks C, et al A

histomorpho-metric meta-analysis of sinus elevation with various grafting materials Head Face Med 2009;5:12.

50 Misch CM Comparison of intraoral donor sites for ridge

aug-mentation prior to implant placement Int J Oral Maxillofac plants 1997;12:767–776.

Im-51 Papageorgiou SN, Papageorgiou PN, Deschner J, Götz W

Com-parative effectiveness of natural and synthetic bone grafts in oral and maxillofacial surgery prior to insertion of dental implants:

Systematic review and network meta-analysis of parallel and cluster randomized controlled trials J Dent 2016;48:1–8.

52 Chackartchi T, Iezzi G, Goldstein M, et al Sinus floor

augmenta-tion using large (1–2 mm) or small (0.25–1 mm) bovine bone mineral particles: A prospective, intra-individual controlled clin- ical, micro-computerized tomography and histomorphometric study Clin Oral Implants Res 2011;22:473–480

53 Testori T, Wallace SS, Trisi P, Capelli M, Zuffetti F, Del Fabbro M

Effect of xenograft (ABBM) particle size on vital bone formation following maxillary sinus augmentation: A multicenter, random- ized, controlled, clinical histomorphometric trial Int J Periodon- tics Restorative Dent 2013;33:467–475.

54 Scarano A, Pecora G, Piattelli M, Piattelli A Osseointegration in

a sinus augmented with bovine porous bone mineral: ical results in an implant retrieved 4 years after insertion A case report J Periodontol 2004;75:1161–1166.

Histolog-55 Wenz B, Oesch B, Horst M Analysis of the risk of transmitting

bovine spongiform encephalopathy through bone grafts derived from bovine bone Biomaterials 2001;22:1599–1606.

56 Holtzclaw D, Toscano N, Eisenlohr L, Callan D The safety of bone

allografts used in dentistry: A review J Am Dent Assoc 2008;

139:1192–1199.

57 Blum B, Moseley J, Miller L, Richelsoph K, Haggard W

Measure-ment of bone morphogenetic proteins and other growth factors

in demineralized bone matrix Orthopedics 2004;27(1 suppl):

s161–s165.

58 Browaeys H, Bouvry P, De Bruyn H A literature review on

bioma-terials in sinus augmentation procedures Clin Implant Dent Relat Res 2007;9:166–177.

59 Galindo-Moreno P, de Buitrago JG, Padial-Molina M, dez-Barbero JE, Ata-Ali J, O Valle F Histopathological compar- ison of healing after maxillary sinus augmentation using xenograft mixed with autogenous bone versus allograft mixed with autoge- nous bone Clin Oral Implants Res 2018;29:192–201.

Fernán-60 Froum SJ, Wallace SS, Elian N, Cho SC, Tarnow DP Comparison

of mineralized cancellous bone allograft (Puros) and anorganic bovine bone matrix (Bio-Oss) for sinus augmentation: Histomor- phometry at 26 to 32 weeks after grafting Int J Periodontics Restorative Dent 2006;26:543–551.

61 Kolerman R, Nissan J, Rahmanov M, Vered H, Cohen O, Tal H

Comparison between mineralized cancellous bone allograft and

an alloplast material for sinus augmentation: A split mouth morphometric study Clin Implant Dent Relat Res 2017;19:812–

reforma-66 Nasr S, Slot DE, Bahaa S, Dörfer CE, Fawzy El-Sayed KM Dental implants combined with sinus augmentation: What is the merit

of bone grafting? A systematic review J Craniomaxillofac Surg 2016;44:1607–1617.

67 Clarizio LF Successful implant restoration without the use of membrane barriers J Oral Maxillofac Surg 1999;57:1117–1121.

68 Jensen OT, Greer RO Immediate placement of osseointegrating implants into the maxillary sinus augmented with mineralized cancelllous allograft and Gore-Tex: Second stage surgical and histological findings In: Laney WR, Tolman DE (eds) Tissue In- tegration in Oral, Orthopedic & Maxillofacial Reconstruction

Chicago: Quintessence, 1991:321–333

69 Wallace SS, Froum SJ Effect of maxillary sinus augmentation on the survival of endosseous dental implants A systematic review

Ann Periodontol 2003;8:328–343.

70 Jonker BP, Roeloffs MW, Wolvius EB, Pijpe J The clinical value

of membranes in bone augmentation procedures in oral tology: A systematic review of randomised controlled trials Eur

implan-J Oral Implantol 2016;9:335–365.

71 Suárez-López Del Amo F, Ortego-Oller I, Catena A, et al Effect

of barrier membranes on the outcomes of maxillary sinus floor augmentation: A meta-analysis of histomorphometric outcomes

Int J Oral Maxillofac Implants 2015;30:607–618

72 Barone A, Ricci M, Grassi RF, Nannmark U, Quaranta A, Covani

U A 6-month histological analysis on maxillary sinus tion with and without use of collagen membranes over the os- teotomy window: Randomized clinical trial Clin Oral Implants Res 2013;24:1–6

augmenta-73 Choi KS, Kan JY, Boyne PJ, Goodacre CJ, Lozada JL, rassaeng K The effects of resorbable membrane on human maxillary sinus graft: A pilot study Int J Oral Maxillofac Implants 2009;24:73–80.

Rungcha-74 García-Denche JT, Wu X, Martinez PP, et al Membranes over the lateral window in sinus augmentation procedures: A two-arm and split-mouth randomized clinical trials J Clin Periodontol 2013;40:1043–1051.

75 Tawil G, Mawla M Sinus floor elevation using a bovine bone

mineral (Bio-Oss) with or without the concomitant use of a

bilay-ered collagen barrier (Bio-Gide): A clinical report of immediate

and delayed implant placement Int J Oral Maxillofac Implants

2001;16:713–721.

76 Avila-Ortiz G, Wang HL, Galindo-Moreno P, Misch CE, Rudek I,

Neiva R Influence of lateral window dimensions on vital bone

formation following maxillary sinus augmentation Int J Oral

Maxillofac Implants 2012;27:1230–1238.

77 Cho YS, Park HK, Park CJ Bony window repositioning without

using a barrier membrane in the lateral approach for maxillary

sinus bone grafts: Clinical and radiologic results at 6 months Int

J Oral Maxillofac Implants 2012;27:211–217.

78 Arora NS, Ramanayake T, Ren YF, Romanos GE Platelet-rich

plasma in sinus augmentation procedures: A systematic literature

review: Part II Implant Dent 2010;19:145–57

79 Del Fabbro M, Bortolin M, Taschieri S, Weinstein RL Effect of

autologous growth factors in maxillary sinus augmentation: A

systematic review Clin Implant Dent Relat Res 2013;15:205–216.

80 Pocaterra A, Caruso S, Bernardi S, Scagnoli L, Continenza MA,

Gatto R Effectiveness of platelet-rich plasma as an adjunctive

material to bone graft: A systematic review and meta-analysis of

randomized controlled clinical trials Int J Oral Maxillofac Surg

2016;45:1027–1034

81 Lemos CA, Mello CC, dos Santos DM, Verri FR, Goiato MC,

Pellizzer EP Effects of platelet-rich plasma in association with

bone grafts in maxillary sinus augmentation: Systematic review

and meta analysis Int J Oral Maxillofac Surg 2016;45:517–525.

82 Peker E, Karaca IR, Yildirim B Experimental evaluation of the

effectiveness of demineralized bone matrix and collagenated

heterologous bone grafts used alone or in combination with

platelet-rich fibrin on bone healing in sinus floor augmentation

Int J Oral Maxillofac Implants 2016;31:e24–e31.

83 Nizam N, Eren G, Akcalı A, Donos N Maxillary sinus

augmenta-tion with leukocyte and platelet-rich fibrin and deproteinized

bovine bone mineral: A split-mouth histological and

histomor-phometric study Clin Oral Implants Res 2018;29:67–75.

84 Cömert Kılıç S, Güngörmüs¸ M, Parlak SN Histologic and

histo-morphometric assessment of sinus-floor augmentation with

beta-tricalcium phosphate alone or in combination with

pure-platelet-rich plasma or pure-platelet-rich fibrin: A randomized clinical

trial Clin Implant Dent Relat Res 2017;19:959–967.

85 Miron RJ, Zucchelli G, Pikos MA, et al Use of platelet-rich fibrin

in regenerative dentistry: A systematic review Clin Oral Investig

2017;21:1913–1927

86 Del Fabbro M, Corbella S, Ceresoli V, Ceci C, Taschieri S Plasma

rich in growth factors improves patients’ postoperative quality

of life in maxillary sinus floor augmentation: Preliminary results

of a randomized clinical study Clin Implant Dent Relat Res

2015;17:708–716.

87 Öncü E, Kaymaz E Assessment of the effectiveness of platelet

rich fibrin in the treatment of Schneiderian membrane

perfora-tion Clin Implant Dent Relat Res 2017;19:1009–1014.

88 Mazor Z, Horowitz RA, Del Corso M, Prasad HS, Rohrer MD,

Dohan Ehrenfest DM Sinus floor augmentation with

simultane-ous implant placement using Choukroun’s platelet-rich fibrin as

the sole grafting material: A radiologic and histologic study at 6

months J Periodontol 2009;80:2056–2064

89 Tajima N, Ohba S, Sawase T, Asahina I Evaluation of sinus floor

augmentation with simultaneous implant placement using

platelet-rich fibrin as sole grafting material Int J Oral Maxillofac

par-92 Froum SJ, Wallace S, Cho SC, et al Histomorphometric ison of different concentrations of recombinant human bone mor- phogenetic protein with allogeneic bone compared to the use of 100% mineralized cancellous bone allograft in maxillary sinus grafting Int J Periodontics Restorative Dent 2013;33:721–730.

compar-93 Corinaldesi G, Piersanti L, Piattelli A, Iezzi G, Pieri F, Marchetti C

Augmentation of the floor of the maxillary sinus with recombinant human bone morphogenetic protein-7: A pilot radiological and histological study in humans Br J Oral Maxillofac Surg 2013;51:247–252

94 Kim HJ, Chung JH, Shin SY, et al Efficacy of apatite on sinus floor augmentation: A multicenter, randomized controlled clinical trial J Dent Res 2015;94(9 suppl):158S–165S

rhBMP-2/hydroxy-95 Froum SJ, Wallace S, Cho SC, et al A histomorphometric parison of Bio-Oss alone versus Bio-Oss and platelet-derived growth factor for sinus augmentation: A postsurgical assessment

com-Int J Periodontics Restorative Dent 2013;33:269–279

96 Kubota A, Sarmiento H, Alqahtani MS, Llobell A, Fiorellini JP

The use of recombinant human platelet-derived growth factor for maxillary sinus augmentation Int J Periodontics Restorative Dent 2017;37:219–225.

97 Zizelmann C, Schoen R, Metzger MC, et al Bone formation after sinus augmentation with engineered bone Clin Oral Implants Res 2007;18:69–73

98 Shayesteh YS, Khojasteh A, Soleimani M, Alikhasi M, Khoshzaban

A, Ahmadbeigi N Sinus augmentation using human MSCs loaded into a beta-tricalcium phosphate/hydroxyapatite scaffold Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106:203–209

99 Fuerst G, Strbac GD, Vasak C, et al Are culture-expanded togenous bone cells a clinically reliable option for sinus grafting?

au-Clin Oral Implants Res 2009;20:135–139

100 Wildburger A, Payer M, Jakse N, Strunk D, Etchard-Liechtenstein

N, Sauerbier S Impact of autogenous concentrated bone marrow aspirate on bone regeneration after sinus floor augmentation with a bovine bone substitute: A split-mouth pilot study Clin Oral Implants Res 2014;25:1175–1181

101 Rickert D, Vissink A, Slot WJ, Sauerbier S, Meijer HJ, Raghoebar

GM Maxillary sinus floor elevation surgery with BioOss mixed with a bone marrow concentrate or autogenous bone: Test of principle on implant survival and clinical performance Int J Oral Maxillofac Surg 2014;43:243–247.

102 Sauerbier S, Rickert D, Gutwald R, et al Bone marrow concentrate and bovine bone mineral for sinus floor augmentation: A con- trolled, randomized, single-blinded clinical and histological trial—Per-protocol analysis Tissue Eng Part A 2011;17:2187–2197.

103 Rickert D, Sauerbier S, Nagursky H, Menne D, Vissink A, hoebar GM Maxillary sinus floor elevation with bovine bone mineral combined with either autogenous bone or autogenous stem cells: A prospective randomized clinical trial Clin Oral Im- plants Res 2011;22:251–258

Rag-104 Gonshor A, McAllister BS, Wallace SS, Prasad H Histologic and histomorphometric evaluation of an allograft stem cell-based matrix sinus augmentation procedure Int J Oral Maxillofac Im- plants 2011;26:123–131.

CHAPTER 2

DIAGNOSIS AND TREATMENT

OF SINUS INFECTIONS

Ashish A Patel, dds, md | Eric J Dierks, dmd, md

Sinusitis or rhinosinusitis is defined as a collection of

inflammatory disorders affecting the paranasal sinuses and nasal cavity In the United States alone, the prev-alence is estimated to be 30 million cases annually To best understand the pathophysiology and subsequent manage-

ment of infectious rhinosinusitis as it relates to dentoalveolar

reconstruction, it is critical to understand the anatomy and

various etiologies that contribute to these disorders

Further-more, rhinosinusitis can also be classified based on its temporal

relationships to symptoms

Diagnosing Rhinosinusitis

Anatomy of the sinus

The maxillary sinus is the largest of the paired paranasal sinuses

and eponymously known as the antrum of Highmore Each

maxillary sinus is a pyramid-shaped cavity with its apex oriented

posteriorly It occupies approximately 15 cubic centimeters of

volume within the midface and is lined by pseudostratified

ciliated columnar epithelium with mucous-producing goblet

cells The cilia beat in harmony at upward of 22 beats per second

toward the ostiomeatal complex to allow non-gravity-dependent

expulsion and drainage of mucous and collected debris into

the nasal cavity The maxillary sinus ostium lies beneath the

middle turbinate, at the superior portion of the medial sinus

wall, approximately halfway between the anterior and posterior

sinus walls, and drains into the infundibulum via an elliptical

aperture that is 2.4 mm in diameter on average A properly

functioning sinus membrane is critical to the health of the

maxil-lary sinus

The ostiomeatal complex is a common channel that links the anterior group of paranasal sinuses (ie, maxillary, frontal, and anterior ethmoid) into the middle meatus It is composed of five distinct anatomical structures: the maxillary ostium, infundib-ulum, ethmoid bulla, uncinate process, and hiatus semilunaris

Patency of this unit is critical in normal sinonasal function and health (Fig 2-1) Anatomical obstruction of the ostiomeatal complex is a major predisposing factor toward the develop-ment of rhinosinusitis because this results in stasis of mucous secretions with proliferation of sinus flora within the antrum

In addition, autoimmune vasculitidies (eg, granulomatosis with polyangiitis, polyarteritis nodosa) or immunosuppressive states have been well associated with rhinosinusitis

Genetic factors and altered host anatomy also contribute, including cystic fibrosis, immotile cilia syndrome, septal devi-ation or spurs, concha bullosa, and paradoxical turbinates.1,2

Concha bullosa is the pneumatization and subsequent ment of the middle turbinate—historically, this was believed

enlarge-to be a source of ostiomeatal complex obstruction, which resulted in a higher incidence of sinusitis, but newer studies

demonstrate that this relationship is nebulous Several

anatom-ical and computed tomography (CT) studies actually

demon-strate a correlation between concha bullosa and nasal septal

deviation, the latter of which has been positively correlated with

the development of rhinosinusitis in several reports.3,4 Other

studies, however, positively correlate concha bullosa and not

nasal septal deviation with the development of rhinosinusitis5

(Fig 2-2).Though the relationship between these endonasal

anatomical abnormalities and the development of sinusitis is

not clearly defined, there does appear to be a trend toward

increased incidence of rhinosinusitis

Signs and symptoms

Diagnosis of rhinosinusitis requires the presence of either (1)

two major factors, or (2) one major and two minor factors as

listed in Box 2-1 It is important to recognize that the

distinc-tion between acute and chronic rhinosinusitis depends not only

on the symptoms, but also the temporal sequence of events

Acute rhinosinusitis has signs and symptoms that persist for

up to 4 weeks; however, chronic disease is defined as lasting at

least 12 weeks It is also possible to have acute exacerbations

of chronic rhinosinusitis with worsening severity of symptoms

in individuals who suffer from chronic rhinosinusitis This is

different from recurrent acute sinusitis, which is characterized

by at least four annual episodes of acute rhinosinusitis, each

lasting longer than 7 days in duration

Viral rhinosinusitis

The most common infectious etiology of rhinosinusitis is

attributed to viruses Viral infections that contribute to the

common cold or upper respiratory infections are the major

culprits for the development of acute sinusitis These include

adenovirus, parainfluenza, influenza, rhinovirus, and

respira-tory syncytial virus Up to 90% of people suffering from upper

respiratory infections will have concomitant sinusitis These symptoms generally do not last more than 10 days and do not continue to get worse as the virus is cleared Because these viruses are air- and particle-borne and are highly infectious, school-aged children are at the highest risk Careful hand hygiene via hand washing or use of alcohol-based hand sani-tizers is perhaps the most effective and efficient way of reducing transmission Though there are many over-the-counter supple-ments and decongestants, none have been proven efficacious

in preventing or reliably reducing the duration of upper ratory infections

respi-Bacterial rhinosinusitis

Though less common than its viral counterpart, bacterial itis poses a more complex problem because it can contribute to the development of chronic or recurrent rhinosinusitis Unlike viruses, bacteria (particularly gram-negative rods) can form a sinonasal biofilm This results in a tenacious layer of bacteria partially protected from antibiotic penetration and mechanical lavage Biofilm-producing bacterial strains, such as pseudomo-nas, can be quite recalcitrant and result in chronic or recurring infections

sinus-The most common bacterial pathogens isolated from patients with acute sinusitis are Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, and Streptococcus pneumoniae

Vaccines are available against H influenzae and S pneumoniae

and are recommended by the Centers for Disease Control and Prevention to be administered to all children Bouts of acute bacterial sinusitis typically follow a viral upper respiratory tract infection (URTI) Though many of the URTI symptoms improve, sinus-associated symptoms persist past 10 days and then worsen over the course of a week These symptoms may last for up to

4 weeks Unlike acute viral sinusitis, which is generally self limited, bacterial sinusitis oftentimes requires medical therapy including the use of systemic antibiotics

Ethmoid bulla Hiatus semilunaris Infundibulum Maxillary sinus ostium Uncinate process

Fig 2-1 Healthy ostiomeatal complex without obstruction Note the

chronic oroantral fistula.

Fig 2-2 Large obstructive concha bullosa with ipsilateral

opacifica-tion of the maxillary sinus.

Diagnosing Rhinosinusitis

Fungal rhinosinusitis

Although uncommon, fungal sinusitis is usually seen as a

chronic disease, and it occurs mostly in diabetic patients

Asper-gillus is the most commonly isolated organism in these cases,

and it forms a mycetoma or aspergilloma, otherwise known as

a fungus ball This is a mass of fungal hyphae arranged

concen-trically forming a sphere-like structure and is best seen on CT

or magnetic resonance imaging (MRI) scans, although in some

patients it can be seen on nasal endoscopy Fortunately,

asper-gilloma is generally self-contained and does not exhibit the

invasive properties of acute fungal sinusitis Both clinically and

radiographically, there is generally a sharp demarcation between

the aspergilloma and surrounding normal sinus tissue as it is

sequestered from the body Endoscopic removal of the

myce-toma with or without systemic antifungals is effective, though

recurrent or recalcitrant cases may also benefit from the addition

of systemic antifungal therapy Chronic fungal rhinosinusitis

often recurs, and this fact must be considered in dental

treat-ment plans that include maxillary sinus floor grafting or other

invasive procedures involving the maxillary sinus

Fungal sinusitis represents a minority of acute sinusitis cases,

but its clinical course and features can be the most

aggres-sive Unlike bacterial and viral sinusitis, acute fungal sinusitis

(also known as invasive fungal rhinosinusitis) almost exclusively

affects individuals with compromised immune systems Patients

under active oncologic treatment or those with hematologic

malignancies, diabetes mellitus, chronic steroid use, or AIDS

are most at risk for developing this potentially devastating and

fatal form of fungal sinusitis

There have been several fungal species isolated from patients

with acute fungal sinusitis, but the two most prevalent

respon-sible pathogens are Mucor and Aspergillus The clinical features

and presentation are more dramatic than that of bacterial and

viral sinusitis and can sometimes be confused with rapidly

evolving malignant processes of the paranasal sinuses In

addi-tion to the signs and symptoms outlined in Box 2-1, patients

suffering from acute fungal rhinosinusitis can also exhibit visual

changes, facial neuropathy or paresthesia, facial or orbital

swell-ing and edema, and epistaxis Furthermore, oral manifestations

are more common in those with fungal sinusitis and may include

palatomaxillary edema, erythema, and paresthesia In advanced

cases, there may be an oroantral communication from palatal

necrosis Anterior rhinoscopy and nasal endoscopy can reveal

frank mucosal necrosis Both CT and MRI scans are useful in

delineating the extent of this disease In addition to the typical

findings of mucosal edema and air-fluid levels in the antrum,

invasive fungal sinusitis can demonstrate tissue necrosis, bone

erosion, and cranial nerve/foramina enhancement

Though these signs seen on advanced sinus imaging may

arouse suspicion for invasive fungal sinusitis, definitive

diagno-sis rests on tissue biopsy to confirm these findings In a recent

series of 13 patients with invasive fungal sinusitis, only 1 had

preoperative CT imaging suggesting bony erosion; however, 6

patients had gross bony invasion noted intraoperatively.6

Invasive fungal sinusitis involving the sphenoid sinus is particularly worrisome because involvement of the adjacent cavernous sinus is almost always fatal Death occurs due to direct intracranial extension and brain abscess, internal carotid rupture, subarachnoid hemorrhage, and sepsis.7,8 The treatment for confirmed invasive fungal sinusitis is hinged both on aggres-sive surgical debridement and systemic antifungal therapy This

is generally completed in an inpatient setting because patients may require multiple debridements and washouts as well as long-term intravenous antifungals As suggested by its name, invasive fungal sinusitis is destructive and may result in irrevers-ible damage to critical structures of the nasal cavity, oral cavity, paranasal sinuses, orbit, and intracranial space Surgical or pros-thetic reconstruction of lost tissue is carried out in a delayed fashion once the active infection has resolved (Table 2-1)

Medical workup

Like other diseases of the human body, careful history and ical examination are the first tools in making a diagnosis of rhinosinusitis This includes anterior rhinoscopy with a nasal speculum and may include office nasal endoscopy as well as subjective olfactory testing In addition to the presence of two major or one major and two minor signs and symptoms (see Box 2-1), imaging can be most helpful in confirming the diagnosis

phys-A CT scan of all the paranasal sinuses (including the atal complex) is standard practice Both wide-field cone beam CTs (CBCTs) as well as medical-grade paranasal sinus CT scans are acceptable, but limited-scope dental CBCT is not helpful

ostiome-Patients with characteristics of sinus inflammation alone, suggestive of viral rhinosinusitis, without the presence of clinical signs and symptoms, do not always warrant imaging or medical

or surgical intervention Sinus CT alone may have false positive rates of 20% to 60% in the diagnosis of sinonasal disorders

Children under 8 years old, in particular, are prone to having incidental mucosal abnormalities in the absence of symptoms on

CT examination This may be due to frequent URTIs in children with residual sinonasal mucosal inflammation

Box 2-1 Diagnostic criteria of rhinosinusitis

Major Minor

Fever (acute) Fever (nonacute)Nasal purulence Dental painNasal obstruction Ear pain/fullnessFacial congestion/fullness Cough

Facial pain/pressure HeadacheHyposmia/anosmia Halitosis

Although it might seem logical to obtain cultures and

anti-microbial sensitivity testing from nasal secretions, this is

gener-ally inaccurate in the diagnosis and management of bacterial

sinusitis The nasal vault is colonized by upper respiratory

flora as well as S aureus Purulent-appearing nasal secretions

do not always represent what is happening within the antrum

Generally, empiric antibiotic coverage for a clinically diagnosed

bacterial sinusitis is sufficient In refractory cases of bacterial

sinusitis or recurrent acute bacterial sinusitis, maxillary sinus

cultures are indicated In these cases, it is imperative to obtain

cultures from the lumen of the antrum and not the nose This

can be accomplished via transnasal endoscopic approaches to

the maxillary sinus or transmucosal or transoral needle

aspi-ration through the anterior sinus wall utilizing an 18-gauge

needle Interestingly, the color of nasal and sinus secretions

is not associated with the severity of sinus disease nor with

the level of infection In addition, purulent discharge does not

necessarily signify bacterial infection, but rather is indicative

of the presence of leukocytes

Treatment of Acute and Chronic

Infections

Antibiotics

Systemic oral antibiotic therapy remains at the core of the

treat-ment algorithm for patients with acute bacterial sinusitis

Simi-lar to dentoalveoSimi-lar infections, the first-line antibiotic of choice

is penicillin based: amoxicillin with or without clavulanic acid

for a 5- to 7-day course.9–13 The rationale for the addition of a β-lactamase inhibitor (ie, clavulanic acid) depends on the suspi-cion of β-lactamase-producing organisms (namely S pneumoniae, and to a lesser degree H influenzae) Patients who fail to respond

to amoxicillin or have sinus cultures demonstrating β-lactamase activity may be candidates for amoxicillin with clavulanic acid

Doxycycline or fluoroquinolones (eg, ciprofloxacin, cin) may be considered for patients with penicillin-resistant bacterial infections or allergies to penicillin.11–13 Macrolide use (eg, clindamycin, azithromycin) is quite common among surveyed medical providers for the treatment of sinusitis, but it should be reserved for penicillin-allergic or second-line therapy because there is growing antibiotic resistance to erythromy-cin.9,10 Though uncommon, methicillin-resistant S aureus can

levofloxa-contribute to acute bacterial sinusitis and would require damycin, sulfamethoxazole and trimethoprim, or linezolid for adequate coverage, depending on the results of sinus culture and sensitivity

clin-Antibiotic therapy for the treatment of chronic sinusitis should ideally be culture directed The antibiotics of choice are the same as that of acute bacterial sinusitis; however, the sinus flora and bacterial colonization are usually more complex, are more likely to include anaerobes, and may have resistant organ-isms if the patient has previously been treated with antibiotics

The use of intravenous antibiotics is reserved for patients with severe infections resulting in systemic inflammatory response syndrome, sepsis, or septic shock The principles of antibiotic therapy are the same as for orally administered treatment, but management of hemodynamics and end-organ function—partic-ularly in those patients who are immunosuppressed—is critical for positive outcomes

Table 2-1 Characteristics of rhinosinusitis

Type of rhinosinusitis Duration Pathogens Treatment

Acute viral Less than 4 weeks Adenovirus, parainfluenza,

influenza, rhinovirus, respiratory syncytial virus

Best supportive care, nasal steroids

Acute bacterial Symptoms worsen 10 days

after URTI, total course less than 4 weeks

H influenzae, M catarrhalis,

S aureus, S pneumoniae Antibiotics, nasal steroids

Acute fungal Less than 4 weeks Mucor, Aspergillus Antifungals, surgical

debridementChronic bacterial At least 12 weeks Mixed, may include

pseudomonas Nasal steroids, sinus hygiene, consider FESS, consider

guided antibioticsChronic fungal At least 12 weeks Aspergillus Surgical excision of fungus ball,

consider antifungals

FESS, functional endoscopic sinus surgery

Other Causes of Sinus Infection

Intranasal steroids

Over the last few years, several clinical trials have demonstrated

the efficacy of intranasally delivered topical glucocorticoids

for the treatment of acute and chronic rhinosinusitis Some of

these products are now available over the counter and can play

a critical role in the treatment of rhinosinusitis Glucocorticoids

inhibit the production of several inflammatory mediators and

reduce the inflammatory response at the transcription level This

results in improvement of nasal and sinus mucosal edema and

engorgement and translates into reduction in clinical symptoms

of both acute and chronic sinusitis as demonstrated by multiple

clinical trials.14 Budesonide, fluticasone, and triamcinolone are

available over the counter via nasal mist and should be used for

a 1-month course Unlike systemic corticosteroids, intranasal

applications demonstrate no systemic adverse effects due to lack

of meaningful systemic absorption Local adverse reactions are

mild and most frequently result in epistaxis or nasal dryness

Sinonasal lavage

Nasal saline administration via a neti pot or sinus douche using

hypertonic saline has been shown to be effective in reducing

the severity and symptoms associated with chronic sinusitis

Unlike nasal saline sprays and mists, the use of a modern neti

pot or sinus douche lavages the maxillary sinus via retrograde

irrigation through the middle meatus and ostiomeatal complex

In addition to appropriate antibiotic therapy, sinus lavage with

saline is an important and effective tool in treating chronic

rhinosinusitis

Other Causes of Sinus Infection

Sinonasal infections associated with

dentoalveolar manipulation and insult

In addition to the common bacterial, fungal, and viral

patho-gens that contribute to infectious rhinosinusitis, infections of

the paranasal sinuses may be iatrogenic in nature Transoral

surgery of the maxillary alveolus or floor of the maxillary sinus

can result in postoperative infections Furthermore, acute

infec-tions of maxillary posterior teeth with root apices inside the

maxillary sinus can result in acute or subacute sinusitis Perhaps

the most common cause of iatrogenic maxillary sinus

pathol-ogy from an oral surgical procedure is extraction of a posterior

maxillary tooth resulting in an oroantral communication These

are troublesome to patients because they may result in nasal

regurgitation of fluids, foul taste or odor, and discomfort or

sensitivity to the local area Though many of these small

perfo-rations close spontaneously, larger openings require adjacent

tissue transfer to seal the defect Unfortunately, a number of

these will persist when there is a baseline deficiency of normal sinonasal drainage due to chronic sinusitis or impaired ostiome-atal complex outflow Pooling of dependent secretions at the site

of the oroantral communication will inevitably result in down of the suture line and refistulization These refractory cases can require functional endoscopic sinus surgery (FESS), including nasal antrostomy to restore adequate sinus drainage while closing the fistula with a robust local tissue flap such as

break-a buccbreak-al fbreak-at pbreak-ad flbreak-ap or pbreak-albreak-atbreak-al islbreak-and flbreak-ap

Other dental insults to the integrity of the maxillary sinus, such as sinus elevation with bone grafting or the placement

of zygomatic implants, are usually well-tolerated by a healthy maxillary sinus with a well-functioning ostiomeatal complex

Patients with borderline function of these areas may not be able to recover from such procedures without postoperative infection resulting from obstruction of maxillary sinus drainage

The most common complication of maxillary sinus elevation surgery is perforation of the sinus membrane Using the open lateral window technique, clinically evident perforations occur

in up to 44% of cases.15,16 Though small perforations (> 5 mm) may repair themselves via a fibrin plug or fold over the membrane, larger perforations (up to 10 mm) may require direct repair if possible and full-thickness coverage with a resorbable collagen membrane It is critical to isolate the bone graft mate-rial from the lumen of the maxillary sinus to prevent ongo-ing contamination or mobilization of graft particles through the ostiomeatal complex Perforation of the sinus membrane during sinus elevation does not necessarily lead to poor dental implant survival when managed appropriately In patients with healthy maxillary sinuses and a functionally adequate ostiome-atal complex, repaired sinus membrane perforations using a resorbable collagen membrane did not adversely affect dental implant survival.17,18

Odontogenic sinusitis

Infections of the maxillary sinus attributed to odontogenic sources may be responsible for up to one-third of all cases of rhinosinusitis Using radiographic and CT criteria, reported rates of an odontogenic source of rhinosinusitis range from 10% to 40%.19 Typically, such cases are unilateral as they are associated with a periapical granuloma or cyst from a necrotic maxillary molar or premolar or large periodontal infections traversing the sinus floor.20,21 The palatal roots from first molars are the roots most frequently associated with odontogenic sinus-itis (Fig 2-3), followed by the mesiobuccal roots from the second molars Interestingly, Eberhardt et al22 used CT scans

in cadavers to demonstrate that the apex of the mesiobuccal root of the second maxillary molar was closest to the sinus floor with a mean distance of 1.97 mm First premolar root apices,

on the contrary, were an average of 7.5 mm away from the sinus floor in the same specimens

Symptomatology is also quite variable depending on the insult to the floor of the sinus and efficiency of the ostiomeatal