1 The rationale for orthodontic treatment 1
2 The aetiology and classifi cation of malocclusion 9
3 Management of the developing dentition 17
4 Craniofacial growth, the cellular basis of tooth movement and anchorage
( Z. L. Nelson-Moon ) 33
5 Orthodontic assessment ( S. J. Littlewood ) 53
6 Cephalometrics 73
7 Treatment planning ( S. J. Littlewood ) 85
8 Class I 101
9 Class II division 1 113
10 Class II division 2 127
11 Class III 137
12 Anterior open bite and posterior open bite 149
13 Crossbites 159
14 Canines 169
15 Anchorage planning ( F. Dyer ) 179
16 Retention ( S. J. Littlewood ) 193
17 Removable appliances 207
18 Fixed appliances 219
19 Functional appliances ( S. J. Littlewood ) 235
20 Adult orthodontics ( S. J. Littlewood ) 251
21 Orthodontics and orthognathic surgery ( S. J. Littlewood ) 263
22 Cleft lip and palate and other craniofacial anomalies 283
23 Orthodontic fi rst aid 295
Defi nitions 302
Index 305
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1 The rationale for orthodontic treatment 1
1.1 Defi nition 2
1.2 Prevalence of malocclusion 2
1.3 Need for treatment 2
1.4 Demand for treatment 4
1.5 The disadvantages and potential risks of orthodontic
treatment 4
1.6 The eff ectiveness of treatment 5
1.7 The temporomandibular joint and orthodontics 6
2 The aetiology and classifi cation of malocclusion 9
2.1 The aetiology of malocclusion 10
2.2 Classifying malocclusion 11
2.3 Commonly used classifi cations and indices 11
2.4 Andrews’ six keys 15
3 Management of the developing dentition 17
3.1 Normal dental development 18
3.2 Abnormalities of eruption and exfoliation 20
3.3 Mixed dentition problems 22
3.4 Planned extraction of deciduous teeth 29
3.5 What to refer and when 30
4 Craniofacial growth, the cellular basis of tooth
movement and anchorage ( Z. L. Nelson-Moon ) 33
4.1 Introduction 34
4.2 Craniofacial embryology 34
4.3 Mechanisms of bone growth 36
4.4 Postnatal craniofacial growth 39
4.5 Growth rotations 42
4.6 Craniofacial growth in the adult 43
4.7 Growth of the soft tissues 44
4.8 Control of craniofacial growth 45
4.9 Growth prediction 46
4.10 Biology of tooth movement 46
4.11 Cellular events associated with loss of anchorage 50
4.12 Cellular events during root resorption 50
4.13 Summary 51
5 Orthodontic assessment ( S. J. Littlewood ) 53
5.1 Introduction to orthodontic assessment 54
5.2 Taking an orthodontic history 54
5.3 Clinical examination in three dimensions 56
5.4 Extra-oral examination 56
5.5 Intra-oral examination 61
5.6 Diagnostic records 63
5.7 Forming a problem list 65
6 Cephalometrics 73
6.1 The cephalostat 74
6.2 Indications for cephalometric evaluation 75
6.3 Evaluating a cephalometric radiograph 76
6.4 Cephalometric analysis: general points 77
6.5 Commonly used cephalometric points
and reference lines 77
6.6 Anteroposterior skeletal pattern 78
6.7 Vertical skeletal pattern 81
6.8 Incisor position 81
6.9 Soft tissue analysis 82
6.10 Assessing growth and treatment changes 83
6.11 Cephalometric errors 83
6.12 3D Cephalometric analysis 84
7 Treatment planning ( S. J. Littlewood ) 85
7.1 Introduction 86
7.2 General objectives of orthodontic treatment 86
7.3 Forming an orthodontic problem list 86
7.4 Aims of orthodontic treatment 87
7.5 Skeletal problems and treatment planning 88
7.6 Basic principles in orthodontic treatment planning 89
7.7 Space analysis 90
7.8 Informed consent and the orthodontic
treatment plan 95
7.9 Conclusions 96
8 Class I 101
8.1 Aetiology 102
8.2 Crowding 102
8.3 Spacing 105
8.4 Displaced teeth 110
8.5 Vertical discrepancies 111
8.6 Transverse discrepancies 111
8.7 Bimaxillary proclination 111
9 Class II division 1 113
9.1 Aetiology 114
9.2 Occlusal features 117
9.3 Assessment of and treatment planning
in Class II division 1 malocclusions 117
9.4 Early treatment 120
Detailed contents
xii Detailed contents
9.5 Management of an increased overjet associated
with a Class I or mild Class II skeletal pattern 120
9.6 Management of an increased overjet
associated with a moderate to severe Class II
skeletal pattern 120
9.7 Retention 122
10 Class II division 2 127
10.1 Aetiology 128
10.2 Occlusal features 129
10.3 Management 130
11 Class III 137
11.1 Aetiology 138
11.2 Occlusal features 139
11.3 Treatment planning in Class III
malocclusions 139
11.4 Treatment options 140
12 Anterior open bite and posterior open bite 149
12.1 Defi nitions 150
12.2 Aetiology of anterior open bite 150
12.3 Management of anterior open bite 152
12.4 Posterior open bite 156
13 Crossbites 159
13.1 Defi nitions 160
13.2 Aetiology 160
13.3 Types of crossbite 161
13.4 Management 163
14 Canines 169
14.1 Facts and fi gures 170
14.2 Normal development 170
14.3 Aetiology of maxillary canine displacement 170
14.4 Interception of displaced canines 172
14.5 Assessing maxillary canine position 172
14.6 Management of buccal displacement 173
14.7 Management of palatal displacement 175
14.8 Resorption 176
14.9 Transposition 177
15 Anchorage planning ( F. Dyer ) 179
15.1 Introduction 180
15.2 Assessing anchorage requirements 180
15.3 Classifi cation of anchorage 183
15.4 Intra-oral anchorage 183
15.5 Extra-oral anchorage 186
15.6 Monitoring anchorage during treatment 189
15.7 Common problems with anchorage 190
15.8 Summary 190
16 Retention ( S. J. Littlewood ) 193
16.1 Introduction 194
16.2 Defi nition of relapse 194
16.3 Aetiology of relapse 194
16.4 How common is relapse? 196
16.5 Informed consent and relapse 196
16.6 Retainers 197
16.7 Adjunctive techniques used to
reduce relapse 200
16.8 Conclusions about retention 201
17 Removable appliances 207
17.1 Mode of action of removable appliances 208
17.2 Designing removable appliances 208
17.3 Active components 209
17.4 Retaining the appliance 210
17.5 Baseplate 212
17.6 Commonly used removable appliances 213
17.7 Fitting a removable appliance 214
17.8 Monitoring progress 215
17.9 Appliance repairs 216
18 Fixed appliances 219
18.1 Principles of fi xed appliances 220
18.2 Indications for the use of fi xed appliances 222
18.3 Components of fi xed appliances 222
18.4 Treatment planning for fi xed appliances 227
18.5 Practical procedures 228
18.6 Fixed appliance systems 228
18.7 Demineralization and fi xed appliances 231
18.8 Starting with fi xed appliances 232
19 Functional appliances ( S. J. Littlewood ) 235
19.1 Defi nition 236
19.2 History 236
19.3 Overview 236
19.4 Case study: functional appliance 236
19.5 Timing of treatment 240
19.6 Types of malocclusion treated with
functional appliances 241
19.7 Types of functional appliance 241
19.8 Clinical management of functional appliances 247
19.9 How functional appliances work 248
19.10 How successful are functional appliances? 249
20 Adult orthodontics ( S. J. Littlewood ) 251
20.1 Introduction 252
20.2 Specifi c problems in adult orthodontic
treatment 2 52
20.3 Orthodontics and periodontal disease 253
20.4 Orthodontic treatment as an adjunct to
restorative work 254
Detailed contents xiii
20.5 Aesthetic orthodontic appliances 257
20.6 Obstructive sleep apnoea and mandibular
advancement splints 260
21 Orthodontics and orthognathic surgery
( S. J. Littlewood ) 263
21.1 Introduction 264
21.2 Indications for treatment 264
21.3 Objectives of combined orthodontics
and orthognathic surgery 266
21.4 The importance of the soft tissues 266
21.5 Diagnosis and treatment plan 266
21.6 Planning 271
21.7 Common surgical procedures 272
21.8 Sequence of treatment 274
21.9 Retention and relapse 278
21.10 Future developments in orthognathic surgery:
3D surgical simulation 278
22 Cleft lip and palate and other craniofacial
anomalies 283
22.1 Prevalence 284
22.2 Aetiology 284
22.3 Classifi cation 284
22.4 Problems in management 285
22.5 Co-ordination of care 287
22.6 Management 288
22.7 Audit of cleft palate care 291
22.8 Other craniofacial anomalies 291
23 Orthodontic fi rst aid 295
23.1 Fixed appliance 296
23.2 Removable appliance 298
23.3 Functional appliance 298
23.4 Headgear 299
23.5 Miscellaneous 299
Defi nitions 302
Index 305
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1
The rationale
for orthodontic
treatment
Chapter contents
1.1 Defi nition 2
1.2 Prevalence of malocclusion 2
1.3 Need for treatment 2
1.3.1 Dental health 3
1.3.2 Psychosocial well-being 4
1.4 Demand for treatment 4
1.5 The disadvantages and potential risks of orthodontic
treatment 4
1.5.1 Root resorption 4
1.5.2 Loss of periodontal support 5
1.5.3 Demineralisation 5
1.5.4 Soft tissue damage 5
1.5.5 Pulpal injury 5
1.6 The eff ectiveness of treatment 5
1.7 The temporomandibular joint and orthodontics 6
1.7.1 Orthodontic treatment as a contributory factor in TMD 6
1.7.2 The role of orthodontic treatment in the prevention and
management of TMD 6
Principal sources and further reading 7
2 The rationale for orthodontic treatment

Numerous surveys have been conducted to investigate the prevalence
of malocclusion. It should be remembered that the fi gures for a particular
occlusal feature or dental anomaly will depend upon the size and
composition of the group studied (for example age and racial characteristics),
the criteria used for assessment, and the methods used by the
examiners (for example whether radiographs were employed).
The fi gures for 12-year-olds in the 2003 United Kingdom Child Dental
Health Survey in are given in Table 1.1 . It is estimated that in the UK
approximately 45% of 12-year-olds have a defi nite need for orthodontic
treatment.
Now that a greater proportion of the population is keeping their teeth
for longer, orthodontic treatment has an increasing adjunctive role prior
to restorative work. In addition, there is an increasing acceptability of
orthodontic appliances with the eff ect that many adults who did not
have treatment during adolescence are now seeking treatment.
It is perhaps pertinent to begin this section by reminding the reader that
malocclusion is one end of the spectrum of normal variation and is not
a disease.
Ethically, no treatment should be embarked upon unless a demonstrable
benefi t to the patient is feasible. In addition, the potential advantages
should be viewed in the light of possible risks and side-eff ects,
including failure to achieve the aims of treatment. Appraisal of these
factors is called risk–benefi t analysis and, as in all branches of medicine
and dentistry, needs to be considered before treatment is commenced
for an individual patient (Box 1.1). In parallel, fi nancial constraints coupled
with the increasing costs of health care have led to an increased
focus upon the cost–benefi t ratio of treatment. Obviously the threshold
for treatment and the amount of orthodontic intervention will diff er
between a system that is primarily funded by the state and one that is
private or based on insurance schemes.
The decision to embark upon a course of treatment will be infl uenced
by the perceived benefi ts to the patient balanced against the risks of
appliance therapy and the prognosis for achieving the aims of treatment
1.1 Defi nition
Orthodontics is that branch of dentistry concerned with facial growth,
with development of the dentition and occlusion, and with the diagnosis,
interception, and treatment of occlusal anomalies.
1.2 Prevalence of malocclusion