Dentofacial and Occlusal Asymmetries

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