Esthetics and biomechanics in orthodontics

620 Pages·2014·340.15 MB·English

by  Ravindra Nanda

ESTHETICS
and
BIOMECHANICS
in
ORTHODONTICS
Second Edition
Ravindra Nanda,
BDS, MDS, PhD
UConn Orthodontic Alumni Endowed Chair
Professor and Head
Department of Craniofacial Sciences
Chair, Division of Orthodontics
School of Dental Medicine
University of Connecticut
Farmington, Connecticut
3251 Riverport Lane
St. Louis, Missouri 63043
ESTHETICS AND BIOMECHANICS IN ORTHODONTICS ISBN: 978-1-4557-5085-6
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Previous edition copyrighted 2005.
Library of Congress Cataloging-in-Publication Data
Esthetics and biomechanics in orthodontics / [edited by] Ravindra Nanda.—2nd edition.
p. ; cm.
Preceded by: Biomechanics and esthetic strategies in clinical orthodontics / Ravindra Nanda. c2005.
Includes bibliographical references and index.
ISBN 978-1-4557-5085-6 (hardcover : alk. paper)
I. Nanda, Ravindra, editor of compilation. II. Nanda, Ravindra. Biomechanics and esthetic strategies in
clinical orthodontics. Preceded by (work):
[DNLM: 1. Malocclusion—therapy. 2. Biomechanics. 3. Esthetics, Dental. WU 440]
RK523
617.6′43—dc23
2013046414
Executive Content Strategist: Kathy Falk
Sr. Content Development Specialist: Courtney Sprehe
Publishing Services Manager: Deborah Vogel
Project Manager: Brandilyn Flagg
Designer: Ashley Miner
Printed in China
Last digit is the print number: 9 8 7 6 5 4 3 2 1
I dedicate this book, with love, to my cherished wife Catherine.
I truly appreciate all that you do for me.
It is because of you all things are possible.
CONTRIBUTORS
Mustafa Burhan Ateş, DDS, PhD R. Scott Conley, DMD
Assistant Professor Robert W. Browne Professor of Dentistry
Department of Orthodontics Clinical Associate Professor
Faculty of Dentistry Department of Orthodontics and Pediatric Dentistry
Marmara University School of Dentistry
Istanbul, Turkey University of Michigan
Ann Arbor, Michigan
Zaher Aymach, DDS, PhD
Visiting Lecturer and Former Doctoral Resident Tarisai C. Dandajena, DDS, MS, PhD
Division of Oral and Maxillofacial Surgery Assistant Professor of Orthodontics and Cell Biology
Tohoku University Department of Orthodontics and Department of Cell
Sendai, Japan; Biology
Post-Doctoral Fellowship–Trained College of Dentistry and College of Medicine
Department of Craniofacial Sciences University of Oklahoma Health Sciences Center
School of Dental Medicine Oklahoma City, Oklahoma
University of Connecticut
Farmington, Connecticut; Nejat Erverdi, DDS, PhD
Post-Doctoral Resident Professor and Full-time University Staff
Department of Orthodontics Marmara University
Howard University Istanbul, Turkey
College of Dentistry
Washington, DC Mithran S. Goonewardene, BDSc, MMedSc
Head and Program Director
Bin Cai, DDS Orthodontics Dental School
Orthodontic Department University of Western Australia
Guanghua School of Stomatology Nedlands, Western Australia
Hospital of Stomatology
Sun Yat-sen University Urban Hägg, DDS, Odont Dr
Guangzhou, Guangdong, China Department of Orthodontics
Institute of Odontology
Taranpreet K. Chandhoke, DMD, PhD Faculty of Health Sciences
Assistant Professor University of Copenhagen
Division of Orthodontics Copenhagen, Denmark
Department of Craniofacial Sciences
School of Dental Medicine Nandakumar Janakiraman, BDS, MDS
University of Connecticut Division of Orthodontics
Farmington, Connecticut Department of Craniofacial Sciences
School of Dental Medicine
Aditya Chhibber, BDS, MDS University of Connecticut
Division of Orthodontics Farmington, Connecticut
Department of Craniofacial Sciences
University of Connecticut Health Center
Farmington, Connecticut
v
vi CONTRIBUTORS
Sunil Kapila, BDS, MS, PhD Padma Mukherjee, BDS, PhD
Robert W. Browne Endowed Professor and Chair Assistant Professor
Department of Orthodontics and Pediatric Dentistry Predoctoral Program Director
Graduate Orthodontics Program Director Department of Orthodontics
University of Michigan Rutgers School of Dental Medicine
School of Dentistry State University of New Jersey
Ann Arbor, Michigan Newark, New Jersey
Hiroshi Kawamura, DDS, PhD Hiroshi Nagasaka, DDS, DDSc
Former Head and Chair Chief Surgeon
Division of Oral and Maxillofacial Surgery Division of Oral Surgery
Tohoku University Sendai Medical Center;
Sendai, Japan Former Lecturer
Division of Oral and Maxillofacial Surgery
Gregory J. King, DMD, DMSC Tohoku University
Professor Emeritus Sendai, Japan
Department of Orthodontics
University of Washington Ram S. Nanda, BDS, DDS, MS, PhD
Seattle, Washington Professor and Chair Emeritus; Founder
Department of Orthodontics
Vincent G. Kokich, DDS, MSD* University of Oklahoma
Professor College of Dentistry
Department of Orthodontics Oklahoma City, Oklahoma
University of Washington
Seattle, Washington Ravindra Nanda, BDS, MDS, PhD
Editor-in-Chief, American Journal of Orthodontics and UConn Orthodontic Alumni Endowed Chair
Dentofacial Orthopedics Professor and Head
Department of Craniofacial Sciences
Vincent O. Kokich, DMD, MSD Chair, Division of Orthodontics
Affiliate Assistant Professor School of Dental Medicine
Department of Orthodontics University of Connecticut
School of Dentistry Farmington, Connecticut
University of Washington
Seattle, Washington Şirin Nevzatoğlu, DDS, PhD
Assistant Professor
Nazan Küçükkeles¸, DDS, PhD Department of Orthodontics
Department of Orthodontics Faculty of Dentistry
Faculty of Dentistry Marmara University
Marmara University Istanbul, Turkey
Istanbul, Turkey
Peter W. Ngan, DMD
Harry L. Legan, DDS Certificates in Orthodontics and Pediatric Dentistry
Private Practice in Orthodontics Department of Orthodontics
Nashville, TN and Laredo, Texas School of Dentistry
West Virginia University
Melih Motro, DDS, PhD Morgantown, West Virginia
Department of Orthodontics
Faculty of Dentistry Marco Rosa, MD, DDS, D.Orthod
Marmara University Assistant Professor
Istanbul, Turkey Postgraduate School in Orthodontics
Insubria University
Varese, Italy
*Deceased.
CONTRIBUTORS vii
Bradley G. Shepherd, BDSc, MDSc Benedict Wilmes, PhD
Private Practice in Prosthodontics Department of Orthodontics
Perth, Australia University of Duesseldorf
Duesseldorf, Germany
Junji Sugawara, DDS, DDSc
Visiting Professor Ricky Wing Kit Wong, BDS, MOrth, PhD, MOrthRCS
Division of Orthodontics Clinical Associate Professor
Department of Craniofacial Sciences Orthodontics Unit of the Faculty of Dentistry
University of Connecticut Health Center The University of Hong Kong
Farmington, Connecticut; Pokfulam, Hong Kong
Visiting Professor
Division of Oral and Maxillofacial Surgery Sumit Yadav, BDS, MDS, PhD
Tohoku University; Assistant Professor
Head, Orthodontic Section Division of Orthodontics
SAS Orthodontic Center Department of Craniofacial Sciences
Sendai, Japan School of Dental Medicine
University of Connecticut
Jae-Hyun Sung, DDS, MSD, PhD Farmington, Connecticut
Professor Emeritus
Kyungpook National University Satoshi Yamada, DDS, PhD
Daegu, South Korea Orthodontist
SAS Orthodontic Center
Madhur Upadhyay, BDS, MDS, MDentSc Sendai, Japan
Director (Orthodontic Fellowship Program)
Assistant Professor Hanife Nuray Yılmaz, DDS, PhD
Division of Orthodontics Research Assistant in the Department of Orthodontics
Department of Craniofacial Sciences Faculty of Dentistry
School of Dental Medicine Marmara University
University of Connecticut Istanbul,Turkey
Farmington, Connecticut
Bjørn U. Zachrisson, DDS, MSD, PhD
Flavio Andres Uribe, DDS, MDentSc Professor Emeritus
Associate Professor Department of Orthodontics
Program Director University of Oslo
Division of Orthodontics Oslo, Norway
Department of Craniofacial Sciences
School of Dental Medicine Xiao-Guang Zhao, BDS, MSD, PhD
University of Connecticut Orthodontic Department
Farmington, Connecticut Guanghua School of Stomatology
Hospital of Stomatology
Carlos Villegas, DDS Sun Yat-sen University
Sociedad Colombiana de Ortodoncia (SCO) Guangzhou, Guangdong, China
Asociación Colombiana de Cirugía Oral y Maxilofacial
(ACCOMF)
World Federation of Orthodontists (WFO)
Asociación Latinoamericana de Cirugía Bucomaxilofacial
(ALACIBU)
Medellín, Colombia
PREFACE
Esthetics and Biomechanics in Orthodontics combines two • Chapter 17: New Treatment Modalities for Class III
of the most important aspects of orthodontic treatment: Malocclusion
esthetics and biomechanics. The basis of orthodontic treat- • Chapter 18: Achieving Optimal Esthetics with Palatal
ment lies in the clinical application of biomechanic concepts, Mini-Implants: The Benefit Technique
and understanding these concepts is imperative to achieving • Chapter 19: Expanding the Limits for Esthetic Strategies
successful treatment outcomes. One of the key objectives of by Skeletal Anchorage
this book is to present how the esthetic objectives of orth- • Chapter 21: Esthetics and New Approaches to Orthogna-
odontic treatment can be successfully obtained with biome- thic Surgery
chanics-based orthodontic appliances. Some of the most • Chapter 22: Surgery First: The Protocol of Innovative Sur-
eminent clinicians and scientists in the field of contemporary gical Orthodontics
orthodontics have come together to provide you with state- • Chapter 24: Interdisciplinary Strategies for Treating Adult
of-the-art guidance on the how the principles of biomechan- Patients
ics can be applied to all orthodontic techniques to improve • Chapter 25: Missing Maxillary Lateral Incisors: New Pro-
force delivery, prevent side effects, and achieve esthetically- cedures and Indications for Optimal Space Closure
pleasing, predictable results.
KEY FEATURES
NEW TO THIS EDITION
In addition to the thirteen new chapters, Esthetics and Bio-
13 NEW chapters
mechanics in Orthodontics includes:
• Chapter 5: Biological Mechanisms in Orthodontic Tooth • Detailed case reports representing key concepts to
Movement improve understanding all of the principles at play in the
• Chapter 7: Biomechanics-Based Management of Im- particular case
pacted Canines • High quality photographs, radiographs, and line draw-
• Chapter 10: Molar and Incisor Positioning to Achieve ings illustrating the various stages of treatment and bio-
Occlusal and Esthetic Objectives mechanical principles
• Chapter 13: Class II Correction with an Intermaxillary • Chapters addressing Individualized Orthodontic Diag-
Fixed Noncompliance Device: Twin Force Bite Corrector nosis and Treatment Planning, both fundamental com-
• Chapter 14: Treatment Strategies for Developing and ponents for successful treatment
Nondeveloping Class III Malocclusions • A distinguished group of practitioners and scholars
• Chapter 15 Clinical Practice Guidelines for Developing from around the world bring their experience and exper-
Class III Malocclusion tise to each topic
ix
ACKNOWLEDGMENTS
My sincere thanks to all the contributors for agreeing to be part of this edition,
and a special thanks to the new contributors who helped
fill the gaps of the first edition.
Dr. Flavio Uribe deserves a special mention for helping me at each and every
step. His work ethic and desire to innovate and share his innovations
through his prolific writing is highly appreciated by all here at the
University of Connecticut. The future of orthodontics is secure
with researchers, clinicians, and mentors like him.
I also want to express my thanks to Madhur Upadhyay, Sumit Yadav,
Preeti Chandhok, Amir Davoody, Jonny Feldman,
and Nandakumar Janakiraman for their contributions at various stages.
They helped to make this book possible.
My thanks also go to my two residents Thomas Dobie and Amir Assefnia
for assisting with the design of cover of this edition and
to Carlos Villegas for providing images of his patient.
A special thanks to Courtney Sprehe, my editor at Elsevier, for pushing me to
complete this project. Her help at each and every step is much appreciated.
My special gratitude to late Vince Kokich for his legendary contributions
to our profession and this book.
x
CHAPTER  1 
Individualized Orthodontic Diagnosis
Flavio Andres Uribe, Taranpreet K. Chandhoke, and Ravindra Nanda
The term diagnosis is defined as the identification of a occlusion was directly related to good facial esthetics.
disease by careful investigation of its symptoms and Although these measurements provide some objective
history.1 While not a true disease per se, malocclu- guidelines that can be used to start defining how each patient
sions are the “disease” processes of orthodontics and the differs from the norm, there are limitations to these analyses.
central focus of orthodontic diagnoses. Malocclusions can Furthermore, it is not the absolute numeric amounts and
have esthetic and functional implications, and an accurate their variation that dictate treatment but the accurate inter-
diagnosis is required to best understand their etiology and pretation of these and all data obtained from the clinical
the treatment options for managing the abnormality. From examination and other patient records.
an esthetic standpoint, there are psychological implications To accurately diagnose a malocclusion, orthodontics has
associated with malocclusions related to social acceptance adopted the problem-based approach originally developed
and success.2 From a functional standpoint, mastication, in medicine.4 Every factor that potentially contributes to the
speech, and protection of the structures in the entire sto- etiology, might contribute to the abnormality, or might influ-
matognathic system can contribute to or be the result of the ence treatment should be evaluated. Information is gathered
malocclusion that is present. through a medical and dental history, clinical examination,
To define the abnormal or pathological characteristics of and records that include models, photographs, and radio-
the malocclusion, there needs to be an appreciation of what graphic imaging. A problem list is generated from the analy-
is defined as “normal.” This is a particular challenge because sis of the database that contains a network of interrelated
what is considered normal falls within a wide range. Vari- factors. The diagnosis is established after a continuous feed-
ability is found throughout nature, so defining the limits of back between the problem recognition and the database.
the normal range can be difficult. While esthetic perceptions Ultimately, the diagnosis should provide some insight into
vary through history and among individuals, races, and cul- the etiology of the malocclusion (Fig. 1-2).
tures, ideal occlusion and its functional implications are The diagnosis and problem list is the framework that dic-
characterized by strict morphological features. Thus the defi- tates the treatment objectives for the patient. Once formu-
nition of a normal occlusion involves both objective and lated, the treatment plan is designed to address those
subjective components. objectives, from the mechanics to the sequence that will
Extensive research has determined the characteristics of be used.
normal functional occlusion. Concepts such as cusp-to-fossa From the treatment objectives perspective, one or more
or cusp-to-interproximal space occlusion, lateral and ante- treatment options can be developed to address each objec-
rior guidance, and mutually protected occlusion are described tive. Each treatment option will have advantages and disad-
comprehensively in other textbooks.3 However, the criteria vantages for the patient. During the process of obtaining
for ideal occlusal function are better defined in comparison informed consent from the patient, clear descriptions of the
to ideal esthetic values. Most of the occlusal concepts advantages, disadvantages, and risks of each treatment plan
accepted today are derived from the assumed premise that should be presented and the patient will ultimately deter-
good anatomy (i.e., good occlusal interdigitation) is analo- mine the final treatment plan. The treatment plan then dic-
gous to proper function (Fig. 1-1). tates the mechanics plan designed to achieve the desired
From the esthetic standpoint, orthodontists base their goals with the greatest efficiency and fewest side effects.
judgment on cephalometric norms obtained many decades This chapter discusses some of the objective measures
ago from population samples with vaguely defined parame- that define the range of normality, both from an occlusal
ters of esthetics. In general, these studies assumed that good and a dentofacial standpoint. It is important to know that
1
2 PART 1 Diagnosis and Esthetic Concepts
A B C
Figure 1-1 A–C, Frontal and lateral views of an ideal occlusion.
Database
Models Photographs- Clinical examination Radiographic imaging
(plaster, Extraoral Intraoral Chief complaint Panoramic x-ray
3D digital) Frontal Upper occlusal Medical history Lateral cephalometric x-ray
Lips lightly touching Lower occlusal Dental history
Lips relaxed Right buccal Extraoral exam
Smiling Left buccal Intraoral exam
Profile Frontal Functional exam
Lips lightly touching
Lips relaxed
45(cid:31) angle
Problems Problems Problems Problems
Problem list
Synthesis and Treatment Mechanics Treatment Treatment
Treatment
diagnosis objectives plan sequence reevaluation
Figure 1-2 Steps in diagnosis and treatment planning.
although emphasis is placed on the entire dentofacial As described above, very precise collection of data is
complex, there are limits to the amount of correction that needed to achieve a proper diagnosis. The database should
can be achieved with orthodontic treatment. include a thorough medical and dental history, a set of
The clinician has to work within certain constraints and models, the necessary radiographs, and a clinical examina-
understand the limitations of the various treatment options. tion accompanied by extraoral and intraoral photographs.
For example, the soft tissue envelope allows for only a certain
amount of correction. If major movements are needed, they CLINICAL EXAMINATION
may require other treatment options such as surgery or skel-
Medical and Dental History
etal anchorage, which, although able to achieve a wider range
of movements, are limited by the boundaries of the soft “What is the patient’s chief complaint?” This question is the
tissue envelope. The primary goal should be to achieve the basis of the anamnesis. At a minimum, the treatment plan
best possible facial balance and functional occlusion. should aim to address this important fundamental compo-
Finally, while great care is taken in formulating a detailed nent of the patient’s initial screening. The clinician is respon-
treatment plan, it is important to realize that the diagnosis sible for accurately understanding and addressing the chief
and treatment plan are dynamic processes. As the plan is complaint. Some patients will have very specific goals for
executed, continuous monitoring and effective evaluation of treatment while others will provide more generalized expec-
the objectives are needed. Appropriate reassessment, adjust- tations. Clear communication is the key to understanding a
ment, and corrective measures to the original plan are crucial patient’s objectives. With young patients, it is usually the
if all specific goals and not only the occlusal goals are to be parents who voice their complaint about the child’s teeth.
achieved. Commonly, the child is lacking in motivation or is too shy