Essentials of Orthodontics E-Book

Robert N. Staley

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 434

Veröffentlichungsjahr: 2010

Beschreibung

Essential Orthodontics: Diagnosis and Treatment is designed to help dental students, orthodontic residents, and general dentists understand the basic concepts and procedures essential to the diagnosis, treatment planning, and treatment of patients who have relatively simple malocclusion problems. The authors explain the steps of diagnosing basic orthodontic problems and analyzing dental radiographs and include many of the forms and charts dentists use for examination, diagnosis, and appliance design. Readers will learn about the mechanics of how appliances move teeth, the different types of appliances, and the orthodontic materials on the market. The authors also explain and demonstrate through color photos how to take dental impressions, create plaster casts, how to create the various fixed and removable appliances, and how to write a laboratory prescription for each appliance. A needed text for the dental student, it is also an excellent resource for dentists wanting to expand their services.

Leseprobe

Table of Contents

Cover

Table of Contents

Half title page

Title page

Copyright page

Dedication

Epigraph

Preface

Acknowledgments

Introduction

1 Orthodontic Diagnosis and Treatment Planning

Normal and Ideal Occlusion

Normal Occlusion in the Primary Dentition

Centric Occlusion and Centric Relation

Angle Classification of Malocclusion

Iowa Notation System for Angle Classification

Rules for Assigning Angle Classification

Rating the Severity of a Malocclusion

Orthodontic Records

Clinical Examination

Summary of Findings, Problem List, and Diagnosis

Consultation with Patient and/or Parent

2 Dental Impressions and Study Cast Trimming

Study Casts

Digital Casts

Alginate Impressions

Mandibular Impression

Maxillary Impression

Record of Centric Occlusion

Pouring of Plaster Study Casts

Study Cast Trimming

3 Dental Cast Analysis in Adults

Tooth Size–Arch Length Analysis

Comparison of TSALD Analysis and the Irregularity Index

Arch Width Measurements

Diagnostic Setup

Mandibular Crowding

Tooth Widths in Normal Occlusion

4 Dental Cast Analysis in the Mixed Dentition

Tooth Size–Arch Length Analysis

Prediction of the Widths of Nonerupted Canines and Premolars

Radiographic Enlargement of Nonerupted Canines and Premolars

Revised Hixon-Oldfather Prediction Method

Iowa Prediction Method for Both Arches

Radiograph Image Problems

Proportional Equation Prediction Method

Tanaka and Johnston Prediction Method

Measurement of Arch Lengths on Casts

Measurement Instruments and Guidelines

Factors that Influence a Mixed-Dentition Arch Length Analysis

Interpretation of a Mixed-Dentition Arch Length Analysis

5 Radiographic Analysis

Periapical Survey

Panoramic Radiograph

Occlusal Radiographs

Cone Beam Radiographs

Lateral Cephalometric Radiographs

Anatomic Landmarks

Cephalometric Landmarks

Cephalometric Point Locations

Cephalometric Planes

Cephalometric Angles and Distances

Skeletal Angles and Distance

Dental Angles

Distances of Incisors to Anterior Vertical Lines

Cephalometric Norms and Treatment Goals

Lateral Cephalometric Tracing

Posteroanterior Cephalometric Radiograph

Analog versus Digital Radiography

6 Lingual and Palatal Arches

Incisor Liability and Leeway Space

Passive Lower Lingual Holding Arch

Prevalence of Incisor Crowding

Premature Loss of a Primary Molar

Asymmetric Loss of a Primary Canine

Nance Holding Arch

Trans-palatal Arch

Insertion of a Passive Lingual or Palatal Arch

Fixed-Removable Lingual and Palatal Arches

Undesirable Side Effects of Passive and Active Lingual and Palatal Arches

Laboratory Prescription and Construction of a Lower Loop Lingual Arch

Failure of a Lower Lingual Arch

7 Management of Anterior Crossbites

Prevalence of Anterior Crossbite Malocclusions

Angle Classification

Centric Relation to Centric Occlusion Functional Shift on Closure

Overbite

Adequate Arch Length

Inclination of Maxillary Incisor Roots

Rotation of Tooth in Crossbite

Number of Teeth in Crossbite

Alignment of Lower Anterior Teeth

Treatment of Anterior Crossbites with Removable Appliances

Treatment of Anterior Crossbites with Fixed Appliances

Construction of a Removable Maxillary Appliance to Close a Diastema and Correct a Lateral Incisor in Crossbite

8 Management of Posterior Crossbites

Definition of Posterior Crossbite

Prevalence of Posterior Crossbite Malocclusions

Angle Classification

Intermolar Width Measurements

Age of Patient

Buccolingual Inclination of the Posterior Teeth

Etiology of Bilateral and Unilateral Posterior Crossbites

Vertical Dimension

Treatment of Posterior Crossbites

Correction of Posterior Crossbites with Removable Appliances

Correction of Posterior Crossbites with Fixed Expander Appliances

9 Management of Incisor Diastemas

Prevalence of Maxillary Diastemas

Etiologic Factors to Consider

Size of Teeth and Bolton Analysis

Arch Size

Maxillary Labial Frenum

Rotated Incisors

Thumb-Sucking Habit

Angle Classification

Management with Appliances

Treatment of a Diastema with a Removable Loop Spring Appliance

Treatment of a Diastema with a Finger Spring Removable Appliance

Treatment of a Diastema Caused by a Thumb Habit

Treatment of a Diastema with the Edgewise Fixed Appliance

10 Molar Uprighting and Space Regaining

Introduction

Ectopic Eruption of Permanent First Molars

Uprighting Molars in the Mixed Dentition

Ectopic Eruption of Upper First Molars

Ectopic Eruption and Tipping of Lower First Molars

Mesial Tipping of Permanent Molars after Loss of a First Molar

Prevention of Molar Tipping after the Loss of a First Molar

Impaction of Second Molars

Loss of Both First and Second Molars

T-Loop Uprighting Spring and Edgewise Fixed Appliance

Forces Generated by the T-loop Uprighting Spring

Patient Treated with a T-Loop Uprighting Spring

Helical Uprighting Spring

Forces Generated by the Helical Uprighting Spring

Patient Treated with a Helical Uprighting Spring

Other Appliances Used to Upright Molars

Repositioning of Teeth Prior to Prosthetic Restoration

11 Orthodontic Examination and Decision Making for the Family Dentist

Introduction

Orthodontic Screening

Guidelines for Orthodontic Decision Making

12 How Orthodontic Appliances Move Teeth

Introduction

Biomechanics

Newton’s First Law

Newton’s Second Law

Keys to Understanding the Delivery of Orthodontic Forces

General Displacements of Rigid Bodies: Euler and Chasles

Limitations of Illustrating Three-Dimensional Tooth Movements in Two-Dimensional Figures

Translation of a Tooth in the Edgewise Fixed Appliance

How a Tooth Is Translated in the Edgewise Fixed Appliance

Rotation of a Tooth in the Edgewise Fixed Appliance

Newton’s Third Law

13 The Edgewise Fixed Appliance

Introduction

The Edgewise Appliance

Arch Wires

Bands

Separators

Fitting a Band

Cementing a Band

Band Cements

Removal of Bands

Bonding of Brackets

Anatomic Considerations

The Straight Wire Appliance™

Bracket and Molar Tube Placement

Direct and Indirect Bonding

Removal of Brackets and Bonded Attachments from Teeth

Arch Form

14 Retention Appliances

Introduction

Fixed Retainers and Tooth Positioners

Invisible Retainers

Essix Retainers

Basic Retainer Design

Wire-Bending Skills

Acrylicing Retainers

Acrylic Finishing and Polishing

15 Orthodontic Materials

Introduction

Orthodontic Wires

Physical Properties of Orthodontic Wires

Wire Sizes

Electric Welding

Flame Soldering

Electric Soldering

Index

This edition first published 2011 © 2011 by Blackwell Publishing, Ltd.

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Library of Congress Cataloging-in-Publication Data

Staley, Robert N.

 Essentials of orthodontics : diagnosis and treatment Robert N. Staley and Neil T. Reske.

p. ; cm.

 Includes bibliographical references and index.

 ISBN 978-0-8138-0868-0 (pbk. : alk. paper)

 1. Orthodontics. I. Reske, Neil T. II. Title.

 [DNLM: 1. Orthodontics–methods. 2. Malocclusion–diagnosis. 3. Malocclusion–therapy. 4. Orthodontic Appliances. WU 440]

 RK521.S73 2011

 617.6´43–dc22

2010028089

A catalogue record for this book is available from the British Library.

This book is published in the following electronic formats: eBook 9780470958414; ePub 9780470958476

Disclaimer

The publisher and the author make no representations or warranties with respect to the accuracy or completeness of the contents of this work and specifically disclaim all warranties, including without limitation warranties of fitness for a particular purpose. No warranty may be created or extended by sales or promotional materials. The advice and strategies contained herein may not be suitable for every situation. This work is sold with the understanding that the publisher is not engaged in rendering legal, accounting, or other professional services. If professional assistance is required, the services of a competent professional person should be sought. Neither the publisher nor the author shall be liable for damages arising herefrom. The fact that an organization or Website is referred to in this work as a citation and/or a potential source of further information does not mean that the author or the publisher endorses the information the organization or Website may provide or recommendations it may make. Further, readers should be aware that Internet Websites listed in this work may have changed or disappeared between when this work was written and when it is read.

Dedication

To: Kathleen H. Staley and Janet L. Reske

Epigraph

We can’t have full knowledge all at once. We must start by believing; then afterwards, we may be led on to master the evidence for ourselves.

Thomas Aquinas

Preface

This book is focused on teaching dental students, orthodontic and pediatric dentistry residents, and dentists the basic concepts and procedures of orthodontic diagnosis and treatment of patients who have simple malocclusion problems. The book is an outgrowth of our experiences in teaching dental students and specialty residents how to diagnose and treat malocclusions that require simple tooth movements. Many patients with the most common problems were followed from the beginning to the end of treatment to illustrate the role of diagnosis and treatment with a variety of appliances. The display of longitudinal records of patients is an important part of the teaching of beginners. The limitations of removable and simple fixed appliances and the problems best treated with one or the other appliance were discussed. We also attempted to help beginners differentiate patients who need simple tooth movements from those who appear to be simple but actually require more complex treatment.

Included are prescriptions and illustrations of the construction of orthodontic appliances used in the treatment of patients with simple tooth movement problems. This knowledge can be useful to laboratory personnel who construct appliances. The connection between fabrication and clinical use of appliances can be helpful to laboratory technicians and clinicians.

Patients with the following malocclusions are not considered as candidates for simple treatment: Class II, Class III, and Class I patients with complications involving severe crowding or extraction of teeth, excessive generalized spacing, severe openbites, deep overbites, and crossbites. The diagnosis and treatment of these patients are beyond the scope of this book.

This book is introductory to orthodontic diagnosis and treatment and is not a definitive source of information. We refer the beginner to the many excellent and more comprehensive books in print and the periodical literature that present in greater depth the concepts of orthodontic diagnosis and treatment.

Our foremost concern is for the welfare of the patient. This concern requires careful consideration before starting orthodontic treatment. Before clinicians move teeth, they must recognize malocclusions and their severity, gain the knowledge to correctly diagnose a malocclusion, and develop the skills to carry out the treatment of a patient.

Acknowledgments

We wish to express our appreciation to several persons who contributed to the preparation of this book. Robert Staley thanks orthodontic laboratory technician Mr. James P. Vance for providing valuable information about laboratory procedures. Neil Reske appreciates the guidance of mentor and friend Mr. Harold Gregorich and teacher Mr. Fred Ulmer, who were instrumental in building a foundation for his laboratory techniques. Mr. James D. Herd, Ms. Patricia J. Conrad, Mr. Ron Irvin, and Mr. Tom Weinsel drew illustrations for the book. Mrs. JoAnne B. Montgomery scanned and adjusted slides for most of the illustrations. We thank Mr. Richard A. Tack for his technical support. Mr. Eric M. Corbin took photographs of appliance construction. We thank Dr. Michael L. Swartz for permission to use orthoclipart illustrations used in Chapters 1 and 13. Dr. George F. Andreasen, former head of the Orthodontic Department, provided helpful suggestions for the discussions involving biomechanics. We thank numerous orthodontic and pediatric dentistry residents who participated in the treatment of several patients described herein. The following faculty of the Orthodontic Department provided radiographs or photographs of patients: Drs. Harold F. Bigelow, Samir E. Bishara, John S. Casko, Theresa L. Juhlin, Karin A. Southard, and Thomas E. Southard. We thank Dr. Thomas E. Southard, head of the Department of Orthodontics, for his support and encouragement of this publication. The following adjunct faculty of the Department of Orthodontics provided invaluable discussions on retention philosophy and laboratory appliance design: Drs. Charles C. Collins, Phillip M. Doster, Paul C. Hermanson, David D. Kinser, and Carney D. Loucks. We thank Dr. Tom M. Graber, who read an earlier edition of the book and provided helpful suggestions for revision. Robert Staley is grateful to Drs. John J. Cunat and Larry J. Green, who introduced him to the specialty of orthodontics at the State University of New York at Buffalo, and Dr. Albert A. Dahlberg, who encouraged him in the study of the biology of the human dentition at the University of Chicago. Dr. Christopher P. Evans proofread the text.

The authors accept full responsibility for the contents of this book.

Introduction

The gathering of information from the patient and steps leading to the development of a diagnosis are discussed in Chapters 1 through 5. Foremost in this section is the recognition of malocclusion, a chair-side skill that is essential for every dentist. Study casts are an important record that will sometime in the near future be obtained digitally from impressions. Dental cast analysis in adults and norms for overbite and overjet are discussed. Prediction of tooth size in the mixed dentition is discussed in Chapter 4. Radiographic and cephalometric analyses are presented in Chapter 5. Cephalometric norms are given for children and adults.

The diagnosis and treatment of commonly observed simple malocclusion problems are described in Chapters 6 through 10. Treatment with lingual arches and the construction of a lower loop lingual arch are included in Chapter 6. The management of anterior cross bites is described in Chapter 7. The construction of an appliance used to close a diastema and correct a crossbite is shown in this chapter. The management of patients with posterior crossbites is discussed and illustrated in Chapter 8. The construction of a removable expander is described in this chapter. The diagnosis and treatment of incisor diastemas are discussed in Chapter 9. The diagnosis and treatment involved with molar up righting and regaining of arch length are presented in Chapter 10. The chapter includes treatment of children and adults with these problems.

The guidelines for differentiating patients who need simple tooth movement from those who need comprehensive treatment are given in Chapter 11. This is a difficult skill to master. The guidelines will help a beginner to successfully choose those patients who have malocclusions appropriate for simple tooth movement.

Chapter 12 is an introduction to biomechanics. Chapter 13 describes the modern edgewise appliance that evolved from its original invention by Dr. Edward H. Angle. Chapter 14 illustrates the construction of removable appliances and retainers. Chapter 15 is a brief summary of materials used in orthodontic treatment.

1

Orthodontic Diagnosis and Treatment Planning

Normal and Ideal Occlusion

To recognize a malocclusion, a clinician needs to understand ideal and normal occlusions. People with ideal occlusions have all 32 adult teeth in superb relationships in all three planes of space. The tip of the mesiobuccal cusp of the upper first molar fits into the buccal groove of the lower first molar, and the tip of the upper canine crown fits into the embrasure between the lower canine and first premolar (Fig. 1.1, Class I ideal occlusion). Overbite, the extent that the upper central incisors overlap the lower central incisors in the vertical plane, is approximately 20%. Overjet, the distance along the anteroposterior plane between the labial surfaces of the lower central incisors and the labial surfaces of the upper central incisors, is approximately 1 to 2 mm. Teeth, moreover, are normally angled in the mesiodistal plane, normally inclined in the buccolingual plane, and aligned without being spaced, rotated, or crowded along the crests of the alveolar processes (Andrews 1972). Ideal occlusions are rare in the United States.

Figure 1.1.A, B, Ideal occlusion in the skeletal remains of a human adult. (Skull “secretum apertum,” courtesy of Dr. Richard Summa.)

Normal occlusions have minimal rotations, crowding, and/or spacing of the teeth. More variability is observed in overbite and overjet in normal occlusions (Fig. 1.2). Normal occlusions are much more frequently observed in the United States than are ideal occlusions.

Figure 1.2.A–E, Normal occlusion in a female adult.

Normal Occlusion in the Primary Dentition

As a child approaches the age when the normal primary dentition transitions into the mixed dentition, spaces develop between the incisors in both arches with growth of the maxilla and mandible (Fig. 1.3). The spacing of primary incisors is needed to accommodate the erupting permanent incisors that are much larger than their primary counterparts.

Figure 1.3.A–E, Normal occlusion in the primary dentition of a 5-year-old boy.

Centric Occlusion and Centric Relation

Occlusion is observed and classified when the teeth are in maximum intercuspation, the definition for centric occlusion. Centric relation is defined as the most retruded occlusal position of the mandible from which opening and lateral movements can be performed (Moyers 1973). Centric occlusion deviated on average 0.7 mm from centric relation in 18 Class I normal occlusion subjects, with a maximum of 2.5 mm; however, in 28 Class II patients, the discrepancy averaged 1.2 mm, with a maximum of 4 mm (Williamson, Caves, Edenfield, and Morse 1978).