Dentofacial and Occlusal Asymmetries

Birte Melsen is the past President of European Orthodontic Society in 2004 and has made significant contributions to the field of orthodontics with her research, publishing around 350 papers in scientific journals on topics related to anchorage (orthodontics) and adult orthodontics. She is currently an orthodontist from Denmark.

Athanasios E. Athanasiou, Executive Dean and Professor of Orthodontics, European University Cyprus, Cyprus; Honorary Professor of Orthodontics, Mohammed Bin Rashid University of Medicine and Health Sciences, UAE.

List of Contributors xiv

1 Introduction 1
Birte Melsen and Athanasios E. Athanasiou

References 3

Part I Etiology 5

2 The Etiology of Dentofacial and Occlusal Asymmetries – An Overview 7
Birte Melsen

Introduction 7

Congenital 7

Postnatally 8

References 14

3 Congenital 15

3.1 Distortion/Malformation 16
Pertti Pirttiniemi

Etiology – Definition 16

Craniosynostosis 16

Plagiocephaly 17

Muscular Torticollis 17

Developmental Dysplasia of the Hip 18

Scoliosis 18

Hemifacial Hyperplasia 18

References 19

3.2 Syndromes and Rare Diseases with Asymmetry in the Craniofacial and Dental Regions 21
Hans Gjørup and Dorte Haubek

Syndromes and Rare Diseases 21

Unilateral Overgrowth of Craniofacial or Dental Structures 22

Unilateral Underdevelopment of Craniofacial or Dental Structures 25

References 33

4 Acquired 37

4.1 Acquired Dentofacial Deformity and Asymmetry 38
Peter B. Stoustrup and Thomas Klit Pedersen

Introduction 39

The Temporomandibular Joint (TMJ) and Its Association with Asymmetric Dentofacial Development 39

Dental Occlusion and Acquired Skeletal and Dental Asymmetries 40

Acquired Dentofacial and Dental Asymmetries 40

Autoimmune Conditions 41

Skeletal Growth Diseases 44

Conditions with Skeletal Undergrowth 44

Conditions with Skeletal Overgrowth 45

Soft-tissue Conditions 46

Temporomandibular Joint (TMJ) Conditions 46

Temporomandibular (TMJ) Disc Displacement (Internal Derangement) 47

Management of Acquired Dentofacial Deformity and Asymmetry 47

Conclusion 50

Acknowledgment 50

References 51

Part II Localization and Problem List 53

5 Examination of Special Features in Patients with Dentofacial and Occlusal Asymmetries 55
Athanasios E. Athanasiou and Birte Melsen

Introduction 55

Head Posture 56

Functional Assessment 58

Photographic Assessment 61

Conclusion 61

References 67

6 Imaging: Craniofacial Asymmetries 69
David C. Hatcher and Vidhya Venkateswaran

Introduction 69

Asymmetry 70

Differential Diagnosis and Decision Tree for a Craniofacial Asymmetry 70

Imaging for Asymmetry 70

Analysis 71

Overall Regional Changes Associated with the Developmental Onset of TMJ Disorders 72

Common Disorders and Associated Local and Regional Changes 74

Conclusions 78

References 81

7 Cephalometric Radiographic Assessment of Facial Asymmetry 82
Guilherme Janson and Aron Aliaga-Del Castillo

Introduction 82

Radiographic Methods for Diagnosis of Asymmetry 82

Concluding Remarks 89

References 89

8 EMG and Ultrasonography of Masticatory Muscles 91
Stavros Kiliaridis

Introduction 91

Understanding the Functional Profile of the Muscle 91

Clinical Methods to Record Masticatory Muscles Functional Capacity 92

Posterior Crossbite with Functional Shift. Effects on Masticatory Muscles? 95

References 96

9 Localization and Problem List – 3-D Face Reconstruction 99
Karine Evangelista, Camila Massaro, Antonio Carlos de Oliveira Ruellas, and Lucia H. Soares Cevidanes

Introduction 99

Facial Asymmetry Diagnosis and Complementary Exams for Facial Asymmetry Localization 100

Image Analysis in CBCT Scans for Skeletal Asymmetry 102

Head Orientation 102

Scroll Through All Cross-Sectional Slices 102

Assessment of the 3D Rendering Viewing from Different Perspectives 104

List of Problems in Skeletal Craniofacial Asymmetries Through 3D Assessment 104

Zygomatic and Maxillary Unilateral Hypertrophy 105

Sinus and Maxillary Hypoplasia 105

Unilateral Condylar Hyperplasia 107

Unilateral Condylar Resorption 109

Craniofacial Macrosomia 110

Asymmetry Localization and Quantification 110

Mirroring and Superimposition 111

Quantification 113

Determining the Asymmetry Directions 114

Final Considerations 114

Acknowledgments 114

References 114

Part III Management 117

10 Treatment Approaches 119

10.1 Very Early Treatment of Dentofacial Asymmetries: Why, When, and How? 120
Ute E.M. Schneider-Moser and Lorenz Moser

Introduction 120

Etiology 121

Diagnostic Evaluation 121

Very Early Treatment for Unilateral Posterior Crossbite with Class I, II, III Malocclusion 123

What if a Class II Subdivision Develops After Early Crossbite Correction? 132

What About Stability of Very Early Crossbite Correction? 141

Summary 141

References 142

10.2 Tooth Movement and Goal-oriented Mechanics in the Treatment of Patients ExhibitingAsymmetry 144
Bhavna Shroff, Steven M. Siegel, Steven J. Lindauer, and Birte Melsen

Introduction 144

Diagnosis – Problem List 145

Molar Rotation (First Order) 147

Molar Tipping (Second Order) 149

Posterior Crossbite (Third Order) 150

Early Loss of Mandibular Deciduous Canines 150

Treatment 152

Correction of Unilateral Molar Rotation 152

Current Mechanics Used to Correct a Class II Subdivision Malocclusion 153

Unilateral Tip-back Mechanics 156

Conclusion 158

References 159

11 Treatment Principles 161

11.1 Dentofacial Orthopedics in the Management of Hemifacial Microsomia and Nager Syndrome Cases 162
Birte Melsen and Athanasios E. Athanasiou

Introduction 162

Case Reports 163

Discussion 171

Conclusion 173

References 173

11.2 Rational Diagnosis and Treatment of Dental Asymmetries 175
Joseph Bouserhal, Nikhillesh Vaiid, Ismaeel Hansa, Zakaria Bentahar, Lea J. Bouserhal, and Philippe J. Bouserhal

Introduction 175

Classification of Dental Asymmetries 176

Diagnosis of Dental Asymmetries 176

Management of Posterior Dental Asymmetries 179

Management of Anterior Dental Asymmetries 181

Conclusions 195

Acknowledgment 195

References 195

12 Orthodontics, Maxillofacial Surgery, and Asymmetries 196

12.1 Dental Arch Shape in Relation to Class II Subdivision Malocclusion 197
Birte Melsen and Padhraig S. Fleming

Introduction 197

Dental Arch Form 197

Case 1 198

Case 2 199

Discussion 199

References 207

12.2 Asymmetric Application of Lingual Arches 208
Kwangchul Choy

Introduction 208

Color Code of the Wire and Force System 209

Shape-driven Concept 209

Force-driven Concept and Definition of Shapes 210

Unilateral Expansion 210

Simulation of Force System 211

Unilateral Tip-back and Unilateral Tip-forward 214

Summary 216

References 219

12.3 Skeletal Anchorage for the Correction of the Canted Occlusal Plane 220
George Anka and Athanasios E. Athanasiou

Treatment of the Canted Occlusal Plane 220

Biomechanics for the Correction of the Canted Occlusal Plane 225

The Trans-Palatal Arch (TPA) Plus Hooks 225

Details of TPA Plus Hooks 231

The Propeller 237

The Ulysses and the Anka-Jorge Plate 240

Extrusion 247

Conclusion 251

References 254

12.4 Managing the Class II Subdivision Malocclusion with Extraction Camouflage: Case Reports 256
Cesare Luzi and Emese Szabò

Introduction 256

Case 1 256

Case 2 259

Conclusions 264

References 268

12.5 The Use of Aligners for Correction of Asymmetries 269
Eugene Chan and M. Ali Darendeliler

Introduction 269

Dental Corrections (Non-extraction Therapies) 270

Dental Corrections (Extraction Therapies) 285

Skeletal Anchorage Therapies 294

Surgical Intervention 309

Conclusions 321

References 328

12.6 TMJ Conditions Causing Facial Asymmetry: Diagnosis and Treatment 329
Larry M. Wolford

Introduction 329

Overdevelopment 329

Unilateral Facial Under-development 335

Adolescent Internal Condylar Resorption (AICR) 336

Reactive Arthritis 338

Trauma 339

TMJ Ankylosis 339

Hemifacial Microsomia (HFM) 341

Connective Tissue/Autoimmune Diseases (CT/AI) 344

References 346

12.7 Distraction Osteogenesis in Maxillofacial Surgery 351
Ioannis Iatrou and Nadia Theologie-Lygidakis

Introduction 351

Biological Basis 351

Staging of Distraction Osteogenesis 352

Indications for Distraction Osteogenesis 352

The Distractors and Their Function 353

Preoperative Patient Evaluation 353

Surgical Procedure 354

Postoperative Procedure – Activation of the Device 358

Complications 359

Orthodontic Collaboration 361

Distraction Osteogenesis and/or Conventional Orthognathic Surgery 362

Conclusion 362

References 362

12.8 Maxillo-mandibular Growth in Hemifacial (or Craniofacial) Microsomia 364
Maria Costanza Meazzini di Seyssel

Introduction – Clinical Appearance 364

Craniofacial Growth in Hemifacial Microsomia 364

Long-term Growth After Distraction Osteogenesis of the Mandible 368

Long-term Results After Costochondral Graft in Growing Patients with Hemifacial Microsomia 368

Clinical and Prognostic Differences in the Orthopedic and Surgical Treatment of Hemimandibular Hypoplasia in Hemifacial Microsomia versus Pseudo-hemifacial Microsomia (or Condylar Coronoid Collapse Deformity) 371

References 377

12.9 Special Treatment Considerations of Face Asymmetries 380
Giampietro Farronato

Introduction 380

Diagnosis 380

Categories of Asymmetry 384

Special Treatment Considerations 393

References 404

12.10 The Vertical Component of Asymmetry: Etiology and Treatment 406
Joseph G. Ghafari

The Three-dimensional Nature of Asymmetry 406

Interaction between Maxillary and Mandibular Asymmetries 407

Unimaxillary Vertical Asymmetry not Affecting the Symmetry of the Other Jaw 411

Conclusion 416

References 416

12.11 Helping Children and Their Families with Facial Differences – Patient Centered Outcomes and Experiences 418
Eleftherios G. Kaklamanos

Introduction 418

The Face as a Functional Structure and as an Element of Identity 419

The Facial Difference from the Patient’s Perspective 420

The Facial Difference from the Family Perspective 422

Psychosocial Support for Children and Families 422

References 423

Index 429