Table Of Content/■
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DIAGNOSTIC
PRINCIPLES
Third Edition
Terrence J Freer
BDSc, D.ORTH, FDS, FRACDS, FICD, PhD
Emeritus Professor of Orthodontics
Christopher TC Ho
BDSc (Hons), MDSc, MRACDS (Orth)
t
Associate Professor of Orthodontics
School of Dentistry
University of Queensland
Or
O
Third Edition
Emeritus Professor Terry Freer
BDSc, D.ORTH, FDS, FRACDS, FICD, PhD
Emeritus Professor of Orthodontics
Associate Professor Christopher T.C. Ho
BDSc (Hons), MDSc, MRACDS (Orth)
Head, Discipline of Orthodontics
School of Dentistry, The University of Queensland
St Lucia, 4072 Australia
The University
Of Queensland
AUSTRALIA
-A'D LIBRARY
Acknowledgements
Appliances used in the textbook were constructed
by Paul Chapman, Danny Kuys, Angelo Mathews
and the Children’s Oral Health Service.
Published by the School of Dentistry
The University of Queensland
St Lucia, 4072 Australia
First Published 1997
Second Edition 1999
Third Edition 2009
ISBN 978 1 86499 939 6
Original design and diagrams by Kira Hogg
Layout by Jerry Liu Design and Photography
The University
Of Queensland
A U S T R A L 1 A
Authors
Emeritus Professor Terry Freer
BDSc, D.ORTH, FDS, FRACDS, FICD, PhD
Emeritus Professor of Orthodontics
I,
Associate Professor Christopher T.C. Ho
BDSc (Hons), MDSc, MRACDS (Orth)
Head, Discipline of Orthodontics
School of Dentistry, The University of Queensland
St Lucia, 4072 Australia
Contributors
Stephen Atkin, Rodney Auer, Hugh McCallum, Gavin Lenz
Children’s Oral HealthService, Royal Children’s Hospital, Brisbane, Australia.
Craig W. Dreyer
School of Dentistry, The University of Adelaide, Adelaide, Australia.
Brett Kerr
School of Dentistry, The University of Queensland, Brisbane, Australia.
Murray C. Meikle
Faculty of Dentistry, National University of Singapore.
Peter G. Miles
10 Mayes Avenue, Caloundra, Queensland, Australia.
Richard Olive
141 Queen Street, Brisbane, Australia.
Desmond C-V. Ong
School of Dentistry, The University of Queensland, Brisbane, Australia.
Pamela Wong
3215 Logan Road, Underwood, Queensland, Australia.
Contents
1 INTRODUCTION 1
2 POST-NATAL CRANIOFACIAL GROWTH 5
3 RADIOGRAPHIC CEPHALOMETRY 21
4 CHARACTERISATION AND CHANGE 37
5 FUNCTION 53
6 DEVELOPMENT OF OCCLUSION 71
7 OCCLUSAL RELATIONSHIPS 93
8 CLASSES AND CATEGORIES 111
9 EXTRACTIONS 125
BIOLOGY OF TOOTH MOVEMENT
10 137
Craig l/IZ Dreyer and Murray C. Meikle
11 BIOMECHANICS OF TOOTH MOVEMENT 159
PRINCIPLES AND MANAGEMENT OF
12 181
REMOVABLE APPLIANCES
13 FIXED APPLIANCES 211
SEQUENTIAL PLASTIC ALIGNERS
14 233
Brett Kerr
LOCALISED ANOMALIES
15 243
Ectopic Teeth by Richard Olive
16 DEMAND. NEED AND MANAGEMENT 275
17 PRINCIPLES OF CLASS II MANAGEMENT 293
18 CLASS II DIVISION 1 MALOCCLUSION 305
19 CLASS II DIVISION 2 MALOCCLUSION 331
20 CLASS III MALOCCLUSION 349
FUNCTIONAL APPLIANCES
21 369
Desmond C-V. Ong
THIRD MOLAR ASSESSMENT
22 389
AND MANAGEMENT
PHARYNGEAL AIRWAY
23 397
Peter Miles
24 ORTHOGNATHIC SURGERY 407
RETENTION, RELAPSE AND STABILITY
25 425
Pamela Wong
26 PATIENT EXAMINATION 435
CLINICAL MANAGEMENT OF PATIENTS WITH
CLEFT LIP AND PALATE
27 449
Christopher T.C. Ho, Stephen Atkin, Rodney Auer,
Hugh McCallum, Gavin Lenz
CASE BASED EXERCISES
28 473
Desmond C-V. Ong
GLOSSARY 491
INDEX 499
Preface to Third Edition
A useful textbook represents the outcome of pragmatism versus idealism. Lengthy
qualifications and arguments are simply not instructive at the undergraduate level.
The broad contributions of authors in this edition provide a balanced compilation
of information which is firmly grounded. They come from diverse educational and
clinical backgrounds and yet have produced a cohesive and consistent resource.
I would like to thank them all. The book reflects evidence-based mainstream
orthodontic teaching and provides the stimulus for progressive learning throughout
the dental student’s journey to graduation. The material is comprehensive but not
overwhelming.
The educational experiences of undergraduates are considerably enhanced by
reference to a consistent central source of knowledge which is not outrageously
expensive. There is little benefit in different instructors using different classifications
of malocclusion or variously interpreting the current evidence on the effects of
functional appliances. Undergraduates are subjected to onerous time demands and
can become lost in a sea of information, some of which is irrelevant. In addition,
universities are moving inexorably toward standardised digital teaching strategies. A
balanced textbook offers a valuable resource in this chameleon-like environment.
I believe the book also provides a useful starting point for postgraduate candidates
in-so-far as it emphasises a basic level of knowledge with which they ought to be
familiar prior to expanding their perspectives with closer study of the published
literature. It is my experience that postgraduate candidates often seek to serve many
masters and fail to grasp the importance of basic and often simple facts. Some also
fail to develop the skills of simplifying and summarising extensive information
sources in an understandable and clinically applicable form.
This third edition is essentially similar to the previous editions and the design, layout
and line drawings are products of the hard work of Kira Hogg and I thank her once
again. Survival to a third edition suggests a continuing relevance. I also thank Chris
Ho for his commitment, good humour and considerable effort in launching this third
edition. Without his contribution it would not have happened. He has been the prime
mover in rewriting some of the text, obtaining updated clinical illustrations and
encouraging other contributors.
TJF
o Introduction
Orthodontics is that branch of dental science concerned with the study and
treatment of dentoskeletal anomalies associated with the growth, development
and function of the dentofacial tissues and structures. The ultimate objective of most
orthodontic treatment is an occlusion which functions normally, maintains oral health
and enhances facial appearance.
Normal occlusion is a variable concept rather than a rigidly defined state. An
occlusion which functions comfortably, has an acceptable appearance, does not
require undue maintenance and does not jeopardise oral health may be regarded as
normal. As a conceptual starting point it is easier to define ideal occlusion. However,
many occlusions which depart from the definition of ideal may still be regarded as
normal.
Clinicians are required to make treatment recommendations based on their experience,
knowledge and the patient’s preferences. The general practitioner must employ
considerable skill in assessing the needs of every patient. Competent assessment
requires an understanding of the patient’s background and aspirations. The dentist is
usually familiar with the patient’s medical and dental histories and how they might
influence compliance. Orthodontic treatment need is sometimes modified by more
pressing personal or socio-economic factors. The practitioner must make a decision,
in consultation with the parent and patient, whether to provide treatment personally,
refer for specialist service or recommend no treatment at all.
Assuming a competent diagnosis, the single most important factor determining the
success of orthodontic treatment is patient cooperation. Few orthodontic treatment
plans can succeed without it and experienced orthodontists devote considerable
expertise to ensuring that the effects of poor compliance are minimised. Orthodontic
treatment for the unwilling patient may be better postponed to a later time. Usually
gingival inflammation and decalcification or caries are the direct consequences of
poor oral hygiene. Additionally, non-compliant patients are often poor attenders so
that orthodontic treatment becomes prolonged and in rare instances may even become
unpleasant for both the patient and the clinician. With the widespread availability of
orthodontic treatment, the need for compliance is underestimated or ignored by many
patients. Where the primary decision to commence treatment is made by the parent,
compliance by the patient is often below expectations. Where compliance is poor,
the clinician may well judge that it would have been better not to have commenced
treatment - a judgment usually made infallibly in hindsight.
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Orthodontic Diagnostic Principles
The discipline of orthodontics presents a particular educational challenge in
the undergraduate curriculum both in terms of content and the time set aside for
orthodontic instruction. Competent orthodontic treatment relies upon competent case
assessment and competent case assessment depends upon a broad understanding of
the morphological and functional concepts of normality. The student must be taught
to integrate knowledge from virtually every dental discipline in formulating a
diagnosis and treatment plan. The objectives of treatment are related not only to the
immediate orthodontic problem but also to those matters which impinge on treatment
planning, including dental health status, cooperation and compliance, family support,
geographical factors and cost. Because most orthodontic treatment is protracted the
clinician is often, by default, expected to supervise management of the patient’s oral
health during the course of treatment.
The time available for orthodontics within the undergraduate curriculum is
necessarily limited by the legitimate demands of other disciplines. Many critics of
new graduates and even the graduates themselves do not always appreciate that there
is keen competition by many disciplines for time in the curriculum. Furthermore,
the content of the undergraduate curriculum has changed substantially in recent
times with the full implementation of courses in gerodontology, dentistry for the
handicapped, gnathology, implantology, infection control and others. All of these
components have been added into the traditional mix so that demands on the student’s
time have become acute, particularly in the clinical years. Some members of the
profession have suggested a period of pre-registration vocational training to ensure
the maintenance of clinical standards.
The undergraduate orthodontic curriculum is usually directed to giving the student
the ability to discriminate between simple and complex cases thereby encouraging
the new graduate to restrict treatment to simple one dimensional objectives. The
problem is that the treatment of virtually any orthodontic anomaly, even the simple
one, may present difficulties which were completely unsuspected at the start and
later require the implementation of strategies which may be outside the capabilities
of the operator. For example, many texts use the single tooth anterior crossbite as an
example of an anomaly which might be simply corrected by means of a removable
appliance. However, this simple anomaly is often complicated by a lack of arch
space, palatal displacement of the root apex or an underlying prognathic mandibular
tendency which will become worse with skeletal development. What seemed to be a
simple treatment problem may become a significant clinical and technical challenge.
This example highlights the dilemma of the orthodontic teacher who strives to provide
the undergraduate with a scientifically grounded methodology yet knows that often
it may not be enough to enable the general dental practitioner to confidently predict
clinical difficulties, responses or treatment outcomes.
Orthodontic teachers, and orthodontists in general, assume a cautious approach to
diagnosis and treatment planning and this caution is often misinterpreted. However,
the need for caution is substantiated by the present climate of increasing litigation
and consumer advocacy. Additionally, the provision of orthodontic treatment is
complicated by the concept of need to improve oral health or psychosocial status.
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