Orthodontics at a Glance E-Book

Daljit S. Gill

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Serie: At a Glance (Dentistry)
• Sprache: Englisch

Seitenzahl: 303

Veröffentlichungsjahr: 2013

Beschreibung

Orthodontics at a Glance is part of the highly popular at a Glance series. It provides a concise and accessible introduction and revision aid. Following the familiar, easy-to-use at a Glance format, each topic is presented as a double-page spread with key facts accompanied by clear diagrams encapsulating essential knowledge.

Structured over four sections, Orthodontics at a Glance covers:

• Craniofacial growth and development
• Diagnosis and treatment planning
• The management of malocclusion
• Treatment techniques

Orthodontics at a Glance is the ideal companion for all students of dentistry, junior clinicians and those working towards orthodontic specialization. In addition the text will provide valuable insight for general dental practitioners wanting to update their orthodontic knowledge, orthodontic nurses, therapists and technicians.

Leseprobe

Contents

Acknowledgements and dedication

1 Introduction

The scope of orthodontic treatment

The demand and need for orthodontic treatment

Where is orthodontic treatment provided?

How is orthodontic treatment provided?

Craniofacial growth and development

2 An introduction to facial growth and development

The importance of understanding facial growth

Components of the skull

Processes involved in skeletal growth (Figure 2.1A)

The control of facial growth

Growth prediction

3 Growth and development of the neurocranium

Cranial vault

Cranial base

4 Growth and development of the naso-maxillary complex

Mechanism of maxillary growth

Timing of maxillary growth

Maxillary growth rotations

Post-adolescent maxillary growth

5 Growth and development of the mandible

Mechanisms of mandibular growth

Timing of mandibular growth

Mandibular growth rotations

Post-adolescent mandibular growth

6 Growth and development of the soft tissues

Growth in lip length

Growth in lip thickness

Nasal growth

Growth of the chin

Facial ageing

7 Development of the dentition

The primary dentition

Eruption of permanent teeth

Mixed dentition

Archform

Diagnosis and treatment planning

8 The aetiology of malocclusion: (i) skeletal and soft tissue factors

Skeletal factors

Soft tissue factors

9 The aetiology of malocclusion: (ii) locals factors and habits

Local factors

Habits

10 Classification of malocclusion

The Angle classification

Incisor classification

Canine relationship

Index of Orthodontic Treatment Need (IOTN)

Peer Assessment Rating (PAR)

11 Principles of orthodontic treatment planning

Risk/cost-benefit analysis

Addressing the patients concerns

Multidisciplinary treatment planning

Aims of treatment

Treatment timing

Importance of the lower incisor position

Extraction versus non-extraction

Limitations of orthodontic treatment

Type of appliance used

Retention

12 Risks and benefits of orthodontic treatment

Benefits of orthodontic treatment

The risks of orthodontic treatment

13 History

The patient’s concerns

Dental history

Family and social history

Medical history

14 Extra-oral examination: skeletal pattern

Assessment of skeletal pattern

Anteroposterior dimension

Vertical dimension

Transverse dimension

15 Extra-oral examination: soft tissues

The lips

Tongue

Habits

TMJ

16 Intra-oral examination

Assessment for pathology

Oral hygiene

Assessment of dental development

Assessment of tooth position

Static and dynamic occlusion

Path of mandibular closure

17 Smile analysis

The lip line

The smile arc

Tooth size and symmetry

The midlines

Buccal corridors

Gingival aesthetics

Embrasures, connectors and contacts

18 Space analysis

Features of a malocclusion to consider in space analysis

Total space requirement

Space creation

Determining anchorage requirements

Effects of growth

19 Orthodontic records

Study models

Radiographs

Photographs

Serial height measurement

Hand-wrist radiographs

Three-dimensional hard and soft tissue scans

20 Cephalometric analysis

Lateral cephalometric analysis

Relationship between the mandible and maxilla

The management of malocclusion

21 Class I malocclusion

Aetiology of Class I malocclusion

Treatment of Class I malocclusion

22 Class II division 1 malocclusion

Aetiology of Class II division 1 malocclusion

Treatment of Class II division 1 malocclusion

Stability of Class II correction

23 Class II division 2 malocclusion

Aetiology of Class II division 2 malocclusion

Treatment of Class II division 2 malocclusion

Stability of Class II division 2 correction

24 Class III malocclusion

Aetiology of Class III malocclusion

Local factors

Treatment of Class III malocclusion

Stability of Class III correction

25 Asymmetries

Developmental causes

Pathological causes

Functional causes

Management of asymmetries

26 Open bite malocclusion

Aetiology of AOB

Treatment of AOB

Stability of AOB correction

27 Deep bite malocclusion

Aetiology of deep OB

Treatment

Stability of OB correction

28 Interceptive orthodontics

Serial extractions

Space maintenance

Infraocclusion

29 Poor prognosis first permanent molars

Consequences of loss of mandibular first permanent molars

Consequences of loss of maxillary first permanent molars

Factors to consider when planning the loss of first permanent molars

Balancing and compensating extractions

30 Crossbites

Aetiology of crossbites

Treatment of crossbites

Stability of crossbite correction

31 Impacted teeth

Impacted maxillary central incisors

Impacted premolars

Impacted first permanent molars

Impacted third permanent molars

32 Impacted maxillary canines

Normal development of the maxillary canine

Aetiology of canine impaction

Clinical and radiographic signs of impaction

Radiographic assessment of canine position

Management of palatally displaced canines

Buccally displaced maxillary canines

33 Hypodontia

Aetiology of hypodontia

Oral anomalies associated with hypodontia

Medical conditions associated with hypodontia

Management of hypodontia

34 Supernumerary teeth

Etiology

Classification

Clinical features

Associated medical conditions

Management

Treatment techniques

35 The biology of tooth movement

Effects of force on the periodontal ligament

Cellular responses to orthodontic forces

The rate of tooth movement

Mechanisms linking force application to tooth movement

36 Biomechanics of tooth movement

Centre of resistance

Forces, moments and couples

Types of tooth movement

37 Anchorage management

Classification of anchorage devices

Factors determining anchorage value

Facial growth and anchorage management

Headgear

38 Removable appliances

Components of removable appliances

39 Functional appliances

Patient selection

Mode of action

Types of functional appliances

40 Fixed appliances

Components of a fixed appliance

Stages of orthodontic treatment

Problems encountered during fixed appliance treatment

41 Stability and retention

Orthodontic stability

Planning retention

Retention appliances

42 Adult orthodontics

Differences between treating adults and children

Orthodontics to facilitate restorative treatment

The periodontally compromised patient

43 Orthognathic surgery

Joint orthodontic-orthognathic clinic

Pre-surgical orthodontics

Joint orthodontic-orthognathic clinic

Model surgery and wafer construction

Surgery

Post-surgical orthodontics

Recall

44 Cleft lip and palate

Aetiology

Classification of CLP

Clinical problems in CLP

Treatment

Appendix 1 The Index of Orthodontic Treatment need (IOTN)

Dental Health Component of IOTN

Aesthetic Component of IOTN

Appendix 2 Commonly used cephalometric points and reference lines

Glossary of orthodontic terms

Index

This edition first published 2008

© 2008 Daljit S. Gill

Blackwell Publishing was acquired by John Wiley & Sons in February 2007. Blackwell’s publishing programme has been merged with Wiley’s global Scientific, Technical, and Medical business to form Wiley-Blackwell.

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ISBN: 9781405127882

Library of Congress Cataloging-in-Publication Data Gill, Daljit S.

Orthodontics at a glance / Daljit S. Gill.

p. ; cm. – (At a glance series)

Includes index.

ISBN-13: 978-1-4051-2788-2 (pbk. : alk. paper)

ISBN-10: 1-4051-2788-0 (pbk. : alk. paper) 1. Orthodontics. I. Title. II. Series: At a glance series (Oxford, England)

[DNLM: 1. Orthodontics–methods–Handbooks. WU 49 G475o 2008]

RK521.G55 2008

617.6′43–dc22

2007042412

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

Acknowledgements and dedication

I would like to acknowledge the following people for permission to reprint figures used within the text:

Staff at the Eastman Dental Hospital (University College London Hospital NHS Foundation Trust, London)/University College London Eastman Dental Institute, London, and Farhad Naini (Consultant Orthodontist, St George’s and Kingston Hospital), for providing some of the photographs used in this book.

Don Enlow and Mark Hans for Figures 3.1A, 4.1A, 4.1B and 4.1C.

Elsevier for Figures 5.1B and 35.1C (from Proffit, W.R. Contemporary Orthodontics).

Orthocare for permission to reprint the Dental Health and Aesthetic components of the Index of Orthodontic Treatment Need. The SCAN scale was first published in 1987 by the European Orthodontic Society (Evans, R. & Shaw, W. Preliminary evaluation of an illustrated scale for rating dental attractiveness. European Journal of Orthodontics 1987;9:314–318).

Dental Update for Figure 17.1B.

Dr Robin Richards (Department of Medical Physics and Bioengineering, University College London, London) for Figure 19.1D.

Finally, I would also like to acknowledge and thank Katrina Chandler and all the production team at Wiley-Blackwell for their enthusiasm, support and hard work throughout this project.

Dedication

I would like to dedicate this text to my parents and grandparents for the opportunities they have given me, their love, kindness and encouragement throughout my life

1

Introduction

Figure 1.1 The scope of orthodontic treatment. Orthodontics can be used for (A) the correction of malocclusion, (B) to facilitate restorative treatment, (C) to aid surgical correction of severe skeletal discrepancies, (D) to facilitate the treatment of cleft lip and palate, and (E) for the comprehensive management of craniofacial deformity as in this patient with Sturge—Weber syndrome.

Figure 1.2 A risk–benefit analysis should be undertaken before commencing orthodontic treatment. Only if the benefits outweigh the risks should treatment be undertaken.

Orthodontics is the specialty of dentistry concerned with growth and development of the face and dentition, and the diagnosis, prevention and correction of dental and facial irregularities. The word orthodontics comes from the Greek words ortho meaning straight and odons meaning tooth.

The scope of orthodontic treatment

Orthodontic treatment is commonly undertaken for the management of malocclusion. Malocclusion is any deviation from normal or ideal occlusion. It should not be considered as a disease but a variation of normal. When such a deviation impacts on an individual’s psychological or dental health one should consider orthodontic treatment.

Besides the management of malocclusion, orthodontics is increasingly being undertaken to enhance the results of other forms of dental and surgical treatment (multidisciplinary care, Figure 1.1A–E). For example, orthodontics can be used to facilitate:

restorative treatment;

the management of severe skeletal discrepancies in combination with orthognathic surgery;

management of cleft lip and palate;

management of severe craniofacial deformity;

management of obstructive sleep apnoea.

The demand and need for orthodontic treatment

The patient’s perception of the need for treatment does not necessarily always correspond with the professional’s viewpoint. Often patients will request treatment when there is very little need on dental health grounds. In other cases, patients may not want to pursue treatment even when there would be a clear dental health benefit. A risk-benefit analysis is a useful method of determining whether to undertake treatment. This involves weighing up the risks and benefits of treatment and only undertaking care if the risks are clearly outweighed by the benefits (Figure 1.2).

The need for orthodontic treatment, based on professional criteria, is dependent on the population studied. The treatment need in the UK, on the basis of the Index of Orthodontic Treatment Need (IOTN, see Appendix 1), is estimated to be approximately 45% in 12-year-olds and 35% in 15-year-olds (IOTN Dental Health Component 4 and 5). The uptake of treatment among females is greater than among males even though the need is equal. In the USA, the treatment need is estimated to be 42% in white adolescents and 30% in black adolescents aged 12–17 years. These figures assume that patients who had already received treatment at the time of survey had a definite need for treatment.

Where is orthodontic treatment provided?

The majority of orthodontic treatment is undertaken within specialist orthodontic practices by orthodontic specialists or dentists with a special interest in orthodontics. The latter are not specialists but have undergone some training in orthodontics in addition to training at the undergraduate level. Hospital services provide treatment for those patients requiring complex multidisciplinary care and management of those malocclusions that are of value for the purposes of teaching and training. In the UK, the community dental services also provide care for people from disadvantaged groups for whom access to treatment is otherwise difficult.

How is orthodontic treatment provided?

The majority of orthodontic treatment is provided with the use of fixed orthodontic appliances. There has been a steady increase in the number of patients treated with fixed appliances over time (Table 1.1). The proportion of patients treated with removable appliances has reduced. The quality of the final occlusal result is significantly improved when fixed appliances are used instead of removable appliances. Removable appliances (e.g. functional appliances) are a useful adjunct to simplifying later fixed appliance treatment. The use of fixed appliances should not be attempted without undergoing comprehensive training.

Table 1.1 Types of appliance worn by 12-year-olds (15-year-olds) at the time of survey in 1993 and 2003 (data taken from UK Child Dental Health Survey).

Percentage of 12(15)-year-olds wearing orthodontic appliances

1993

2003

Fixed

49% (68%)

72% (83%)

Removable

50% (37%)

28% (18%)

Craniofacial growth and development

2

An introduction to facial growth and development

Figure 2.1 (A) The four main processes involved in growth and development of the craniofacial complex. (B) Various cephalometric features can indicate the likely direction of mandibular growth rotation. These features include the lower anterior face height, the shape of the lower border of the mandible, the inclination of the mental symphysis, inclination of the condylar head and curvature of the mandibular canal. () The general pattern of skeletal and neural growth is illustrated (Scammons curves). Mandibular growth has some similarity to the general skeletal growth pattern. () This figure shows the height curve for males. The average growth curve (50th centile) as well as curves between the 3rd and 97th centile are shown. The pubertal growth spurt is marked as well as the secondary sexual characteristics that may be present at the beginning and end of the spurt. At least three consecutive measurements (red crosses) are required to estimate with reasonable accuracy the growth curve any particular patient maybe following.