Illustrated Manual of Orthognathic Surgery: Pre-surgical Steps and Osteotomies of the Mandible

This first volume in a multi-volume series considers the gains in information and knowledge that have resulted from preoperative and postoperative 3D imaging using new radiologic protocols in maxillofacial surgery, with the corresponding consequences for the surgeon. It contrasts the established standard techniques of orthognathic oral and maxillofacial surgery with new considerations and insights based on years of experience and analysis of clinical activity in this subspecialty of oral and maxillofacial surgery. The book is deliberately structured so that the clinical situation is juxtaposed with a graphic representation for better understanding, which is intended to point out special situations that can in turn positively influence the surgical planning and execution of the procedure in order to avoid undesirable results in individual cases. Graphic representations illustrate the three-dimensionality of the complex splitting technique of the mandible where text or radiographs are insufficient. A corresponding book that combines clinical anatomical situations with pre- and postoperative preparation and clear explanation does not yet exist. It is aimed at a wide readership of students and professionals in oral and maxillofacial surgery, orthodontics, plastic and craniofacial surgery, and otolaryngology. Preface Contents Part I: Introduction to Orthognathic Surgery in the Mandible 1: Evolution of the Surgical Standard Techniques 1 Inverted L Osteotomy and C Osteotomy 2 The Development of Horizontal Ramus Osteotomies to Extended Sagittal Ramus Splitting 3 Oblique Retromolar Osteotomy 4 Conclusion References Further Readings 2: Classification and Facial Patterns 1 Introduction 2 Skeletal Dysgnathia 2.1 Symmetric Dysgnathia 2.2 Asymmetric Dysgnathia 3 Dentoalveolar Dysgnathia 4 Surgical Classification of Dysgnathias 5 Asymmetric Skeletal Growth Disorders 6 Facial Patterns in Typical Forms of Dysgnathia 6.1 Mandibular Growth 6.2 Anterior Mandibular Rotational Growth Pattern 7 Conclusion References 3: Types of Osteotomies in the Mandible 1 Introduction 2 Surgical Corrections in the Lower Jaw 2.1 Ramus Osteotomies 2.2 Mandibular Body Osteotomies 2.3 Segmental Osteotomies 2.4 Chin Osteotomies 3 Classification of Surgical Corrections 4 Conclusion Further Reading 4: Definition of Standard Procedures 1 Bilateral Sagittal Split Osteotomy - BSSO/Osteotomies in the Mandible 1.1 Indications—Standard Sagittal Split Osteotomy 1.2 Surgical Principle—BSSO 1.3 Sagittal Splitting as Setback Surgery 1.3.1 Principle 1.4 Sagittal Splitting as Advancement Surgery 1.4.1 Principle 1.5 Mandibular Body Osteotomy 1.6 Stepwise Osteotomy 1.6.1 Principle 1.7 Horizontal Mandibular Distraction Osteogenesis 1.7.1 Indication 1.7.2 Principle 1.8 The Anterior Mandibulotomy 1.8.1 Indications 1.8.2 Technique 2 Segmental Alveolar Osteotomies 2.1 Anterior Subapical Osteotomy 2.1.1 Principle 2.2 Posterior Subapical Osteotomy 2.2.1 Indication 2.2.2 Principle 3 Chin Osteotomies 4 Principal Surgical Techniques in Chin Osteotomies 4.1 Horizontal Sliding Genioplasty 4.2 Horizontal Sliding Osteotomy 4.3 Oblique Osteotomy for Chin Advancement 4.4 Jumping Genioplasty 4.5 Centering Genioplasty 4.6 Two-Tiered or Tandem Genioplasty 4.7 Chin Wing Osteotomy 4.8 Less Common Variants and Alternatives 5 Conclusions References Part II: Ramus Split Osteotomies / Bilateral Sagittal Split Osteotomies (BSSO) - General Planning 5: The Patient 1 Intake 2 Clinical Examination and Photo Documentation 2.1 Examination of the Face from Top to Bottom 3 Dental Examination (Fig. 5.9) 3.1 Additional Clinical Examination 3.2 How to Proceed 3.3 Facebow 4 Conclusion Further Reading 6: Radiology and Basic Measurements 1 Radiological Imaging 1.1 Panoramic X-Ray 1.2 Lateral Cephalometric X-Ray 1.3 Cone-Beam Computed Tomography (CBCT) 1.4 Multi-Slice Computed Tomography (MSCT) 1.5 CT-Based Distance Measurements in the Pre-Masseteric Region (Buccal Osteotomy) 1.6 CT-Based Distance Measurements in the Region of the Mandibular Angle 2 Conclusion References 7: General Planning and Preoperative Assessment 1 2D Cephalometric Analysis 1.1 Tracing 1.2 Marking of Anatomical Landmarks and Planes 1.3 Analysis 1.3.1 Important Angles Used for Measuring Skeletal Relations 1.3.2 Important Angles Used for Measuring Dental Relations 2 Soft Tissue Analysis 2.1 Planning 2.1.1 Mandibular Retrognathism. 2.1.2 Mandibular Prognathism and Maxillary Retrognathism. 2.1.3 Mandibular Retrognathism and Maxillary Prognathism. 3 3D Imaging and 3D Planning 3.1 Using Virtual Surgery Planning 3.2 Summary of the Advantages of 3D Imaging and 3D Planning 4 Conclusion References 8: Preparations for the Surgical Procedure 1 A Short Guideline for the Patient Journey in Orthognathic Surgery 1.1 The First Contact—Basic Analysis 2 Take a Thorough Medical History and Deliver Appropriate Information 2.1 The Second Contact 2.2 The Third Contact 3 Specific Advice 3.1 The Week before Surgery 3.2 The Operation Day 3.3 Pre- and Perioperative Medication 4 Instructions at the End of Operation 5 Conclusion Further Reading 9: Osteosynthesis for Sagittal Splitting 1 Wire Osteosynthesis/ Intermaxillary Fixation 2 Rigid Internal Segment Fixation 2.1 Advantages of Rigid Internal Fixation (RIF) 2.2 Long-Term Versus Short-Term MMF 3 Osteosynthesis Techniques 4 Rigid Screw Osteosynthesis 4.1 Rigid Bicortical Compression Screw Osteosynthesis 4.1.1 Application 4.2 Rigid Bicortical Positioning Screw Osteosynthesis 4.2.1 Application 5 Rigid Internal Fixation: Osteosynthesis Plates 5.1 Rigid Monocortical Miniplate Osteosynthesis 5.2 Conventional Osteosynthesis Plates 5.3 Open Sagittal Split Osteosynthesis Plate 5.3.1 Application 5.4 Closed Sagittal Split Plates with Sliding Function 5.5 Monocortical Miniplate-Osteosynthesis Versus Bicortical Compression and Positioning Screw Osteosynthesis 6 Osteosynthesis and Segment Positioning 6.1 Osteosynthesis with Intersegmental Distance 6.2 Condylar Position after BSSO and Bicortical Screw Fixation 6.3 Osteosynthesis with Temporomandibular Dysfunction and Intersegmental Gaps 7 Rigid Osteosynthesis and Condylar Head Position 7.1 Postoperative Changes in Condylar Position 7.2 Rotation of the Condyle 7.3 Change of the Intercondylar Distance 8 Osteosynthesis and Trauma of the Alveolar Nerve 9 Osteosynthesis and Bone Healing 10 Removal of Osteosynthesis Material 11 Revascularization and Bone Healing 11.1 Immediately Postoperative 11.2 One Week Postoperative 11.3 Two Weeks Postoperative 11.4 Three Weeks Postoperative 11.5 Six Weeks Post-op 11.6 12 Weeks Postoperative 12 Conclusion References 10: Pre- and Peri-operative Care in Orthognathic Surgery - Anesthesiology and CMF-Surgery 1 Preoperative Phase 1.1 Anesthesiology: Preoperative Checks 1.2 Pre-op Medical Examination for Orthognathic Procedures 1.3 Orthognathic Procedures (Mandibular +/− Maxillary Osteotomies) 2 CMF Surgery: Preoperative Checks 3 Anesthesiology 3.1 Preoperative Medications: Have to Be Continued as a General Rule 3.2 Procedure in Patients with Platelet Aggregation Inhibitors 4 Anesthesia and CMF Surgery: Preoperative Assessment 4.1 Intubation Form: Decision with CMF Surgeon 4.1.1 Types of Endotracheal Tubes (ETT): Intubation 4.1.2 Intubation: Technique 4.1.3 Naso-tracheal Intubation: In CMF Operations 4.2 Intubation Problems 4.2.1 Difficult Airway: Definition 4.2.2 Estimation of ITN Difficulty 4.2.3 Anamnestic ITN Difficulties 4.3 Patients: Positioning: Determination with CMF Surgeon 5 Perioperative Phase: Anesthesia procedure in CMF Surgery 5.1 Preparation 5.2 Anesthesia Induction 5.2.1 Critical Moments: Tubs Displacement/Disconnection 5.3 Maintenance: ITN Anesthesia 5.4 Recovery: Emergence 5.4.1 Requirements for Anesthetic Discharge 5.4.2 Extubation Criteria 5.4.3 Measures before Extubation 5.4.4 Extubation 5.5 Documentation 5.5.1 Anesthesia Protocol 6 Perioperative Phase: Prophylactic Measures in CMF Surgery 6.1 Perioperative Prophylaxis with Antibiotics 6.1.1 Alternative Proposals 6.1.2 Alternative Proposals in Cases of Allergy 6.2 Perioperative Pain Prophylaxis 6.2.1 Basic Pain Therapy 6.2.2 Enhanced Pain Therapy 6.2.3 Severe Pain Therapy 6.3 Perioperative Prophylaxis against Swelling 6.4 Postoperative Nausea and Vomiting: PONV Prophylaxis 6.4.1 Influencing Factors 6.4.2 Prophylaxis: Reducing Emetogenic Influence 7 Conclusion References 11: Postoperative Care in Orthognathic Surgery 1 Postoperative Management 1.1 Postoperative Instructions 1.2 For the Later Postoperative Phase 1.3 Postoperative Management in the Recovery Room 1.3.1 Standard Basic Monitoring 1.3.2 Clinical Examination 1.3.3 Cardiovascular Function 1.3.4 Neuromuscular Function 1.3.5 Pain Level 1.4 Controlling the Surgical Area in Orthognathic Surgery 1.5 Final Clinical Assessment 1.5.1 Example I: CMF-Surgery [1] 1.5.2 Example II: Orthognathic Surgery (Adapted from [1]) 2 Postoperative Therapy of Postoperative Nausea and Vomiting (PONV) 2.1 On the Recovery 2.2 On the Ward 2.3 Postoperative Drug Thrombosis Prophylaxis 2.3.1 Indication 3 Restart of a Pre-Existing Continuous Medication 3.1 Cardiovascular Medication 3.2 Antidiabetics in Diabetes Patients 3.3 Corticosteroid Medication 3.4 Postoperative Hydration and Oral Nutritional Supplementation 3.5 Dietary Structure 4 Wound Care in Orthognathic Surgery 4.1 Postoperative Considerations 4.2 Intraoral Wound Treatment 4.2.1 Oral Hygiene 5 Conclusion Reference Part III: Bilateral Ramus Split Osteotomies (BSSO) - Surgical Principles 12: Principles of the BSSO – Clinical Aspects 1 Transoral Approach to the BSSO—Line of Thoughts 2 Conclusion References 13: Relation of Cortical Versus Cancellous Bone – The Crucial Ratio 1 The Mandibular Canal: A Crucial Structure of Lower Resistance 2 Anatomical Variants of the MC: Canal Course 3 Conclusion References 14: Anatomical Reference Points – Indispensable Aids 1 Conclusion Reference 15: General Rules in Sagittal Splitting – Five Steps 1 Surgical Approach 2 Access to the Lateral Side of the Ascending Ramus: Submasseteric Space 3 Access to the Medial Side of the Ascending Ramus: Pterygo-Mandibular Space 4 Creation of the Osteotomy Lines 4.1 Upper Horizontal Osteotomy (Lingual Osteotomy) 4.2 Lower Vertical Osteotomy (Buccal Osteotomy) 4.3 Sagittal Connecting Osteotomy 5 Reference Points for Osteosynthesis 5.1 Bi-Cortical Screws 5.2 Mono-Cortical Screws and Miniplates 6 Conclusion Further Reading 16: BSSO Relevant Clinical and Topographic Anatomy (Studies and Variations) 1 Topography of the Mandibular Foramen (Fig. 16.1) 2 Topographic and Metric Relations on the Lingual Side of the Ascending Mandibular Ramus 2.1 Position of the Anti-Lingula Opposite to the Lingula/Mandibular Foramen 2.2 Vertical and Horizontal Measurements Between the Mandibular Foramen and the Borders 3 Topographic Determination of the Lingual Osteotomy 4 Lingual Osteotomy Line and Cortex Fusion above the Mandibular Foramen 5 The Neurovascular Bundle 5.1 Care of the Neurovascular Bundle 6 BSSO and Vascular Structures in the Vicinity of the Lingual Aspect of the Ascending Ramus 7 Variants of the Upper Horizontal Osteotomy (Lingual Osteotomy) 8 Variants of the Vertical Osteotomy (Buccal Osteotomy) 9 Variant of the Sagittal Osteotomy 10 Conclusion References 17: Strategic Surgical Approach and Technical Details 1 Anatomical Basis of Mandibular Bone Splitting 1.1 Splitting Technique of the Ramus in the Borderline between Lateral Cortical and Cancellous Bone 2 Sagittal Split Osteotomy of Mandible (BSSO)—Surgical Technique Surgical Access 2.1 Intraoral Mucoperiosteal Incision 2.2 Exposure of the Ramus and the Buccal Region of the Second and Third Molars 2.3 Anterior and Inferior Exposure of the Coronoid Process 2.4 Exposure of the Lateral Side of the Ramus (Sub-Masseteric Space) 2.5 Exposure/Dissection of the Lingual Side of the Ramus (Pterygomandibular Space) 3 The Osteotomy Lines 3.1 Horizontal Bone Cut—Horizontal Osteotomy 3.2 Vertical Bone Cut—Vertical Osteotomy 3.3 Sagittal Bone Cut—Sagittal Osteotomy 4 Sagittal Splitting 4.1 Pre-Angular Section 4.2 Angular and Supra-Angular Section 4.3 Mandibular Angle Beneath the Nerve Canal 4.4 Advanced Splitting 4.5 Splitting of the Mandibular Margin 4.6 Difficulties in Mandibular Splitting 4.7 After the Split 5 Conclusion References 18: Intraoperative Hazards and Risks 1 Vascular Injuries 2 Prevention of Vascular Injuries in the Pterygomandibular Space 2.1 Inferior Alveolar Artery 2.2 Maxillary Artery 3 Prevention of Vascular Injuries in the Retromandibular Region 3.1 Retromandibular Vein/Retromandibular Venous Vascular Plexus 4 Intraoperative Measures for Vascular Lesions 4.1 Inferior Alveolar Artery 4.2 Maxillary Artery 4.3 Facial Artery 5 Nerve Injuries 6 Paresthesia/Anesthesia 7 Damage to the IAN 7.1 In Detail, Intraoperative Injuries of the IAN Occur: 7.2 Injuries to the Inferior Alveolar Nerve Can Be Avoided by: 7.3 Treatment of IAN Injuries 7.3.1 Complete Transection of the Inferior Alveolar Nerve—IAN 8 Damage to the Lingual Nerve 8.1 Injuries to the Lingual Nerve can be avoided by: 8.2 Treatment of Lingual Nerve Injuries 8.2.1 Complete Transection of the Lingual Nerve 9 Damage to the Facial Nerve 10 Split Patterns during BSSO 10.1 Sagittal Split Variants 10.2 Bad Splits in BSSO 10.3 Danger Points: Bad Split 10.4 Avoidance of Bad Splits 11 Complications during and Immediately after Extubation 12 Conclusion References Further Readings 19: Surgical Tricks 1 Display of Important Anatomical Points and Structures in BSSO 1.1 Mucoperiosteal Incision in Relation to the Nerve Branches near the Ramus, the Muscular and Vascular Structures 2 Preparation of the ­Masseterico-mandibular and Pterygo-Mandibular Spaces 3 Identification of the Mandibular Foramen and the Neurovascular Bundle 4 Creation of Bone Cuts in Preparation of the Sagittal Split (SSRO/BSSO) 4.1 The Sagittal Osteotomy Line 5 Creation of the Horizontal Osteotomy Line (Fig. 19.7) 6 Creation of the Vertical/Buccal Osteotomy Line 7 Correct Transitions and Pre-splitting of the Osteotomy Sections 8 Correct Mandibular Split 8.1 Technique of the Pre-angular Split 8.2 Technique of Angular and Post-Angular Split 8.3 Avoidance of latrogenic Fractures during Splitting in the Proximal Segment: Lingual Split 8.4 Avoidance of latrogenic Fractures during Splitting in the Angular Region below the Mandibular Canal 9 Piezosurgical Splitting of the Inferior Mandibular Rim 10 Avoidance of Caudal-Basal Step formation in the Area of the Vertical Split 11 Conclusion References Further Reading 20: Post-Surgical Complications and Care 1 Immediate Complications after Orthognathic Surgery 1.1 Mechanical Airway Obstruction 1.2 Functional Respiratory Insufficiency 1.3 Bronchospasm 1.4 Tracheal Edema 1.5 Tachypnea and Shortness of Breath 1.6 Aspiration 1.7 Postoperative Nausea and Vomiting (PONV) 1.8 Reasons 2 Pain Management 2.1 Algorithms for Pain Therapy 2.2 Expected Pain Level 2.3 Pain Therapy on the Ward 2.4 Postoperative Pain Therapy—Pain Score and Basic Medication 2.4.1 Mild Pain (NRS 1–3) 2.4.2 Moderate Pain (NRS 4–6) 2.4.3 Severe Pain (NRS 7–10) 2.5 Postoperative Facial Swelling 2.6 Postoperative Fever 3 Indirect Complications after Orthognathic Surgery 3.1 Wound Infections 3.2 Postoperative Soft Tissue Infections 3.3 Postoperative Bone Infections 3.4 Delayed Bone Union or Bone Non-union 3.5 Mandibular Relapse 3.6 Factors that Can Lead to a Relapse after Mandibular Split are 3.7 Mandibular Relapse and Rotation 3.8 Mandibular Relapse and Intersegmental Distance 3.9 Malocclusion 3.10 Bone Necrosis 3.11 Prophylaxis 3.12 Pseudarthrosis 4 Conclusion References Part IV: Mandibular Deficiency - Surgical Technique - BSSO 21: Indications for Mandibular Advancement 1 Morphological and Dental Criteria 1.1 Skeletal Relation—Possible Conditions 1.2 Dentobasal Relation—Possible Conditions 2 Cephalometry in Skeletal Mandibular Retrognathia: 3 Indications 4 Conclusion Reference 22: Sagittal Split and Mandibular Advancement 1 Mandibular Advancement: BSSO 2 Combination of Osteotomies 2.1 Segment Osteotomies 3 The Chin 4 Conclusion References 23: Special Surgical Aspects in Mandibular Advancement - Flaring 1 Anatomical Surgical Background 2 Modifications and Surgical Alternatives 3 Conclusion Reference 24: Intermolar Mandibular Distraction Osteogenesis IMDO 1 Indication 1.1 Indications for Intermolar Osteotomy and DOG are 2 Surgical Procedure 3 Surgical Steps: 4 Distraction/Treatment Protocol: 5 The Clinical Treatment Phase 6 Radiological Follow-Up: 7 Clinical Follow-Up 7.1 Advantages and Disadvantages of IMDO Treatment 8 Conclusion References 25: Retromolar Mandibular Distraction Osteogenesis RMDO 1 Indication 2 Surgical Procedure 3 Surgical Steps: 4 Distraction Protocol: 5 The Clinical Treatment Phase 5.1 Advantages and Disadvantages of RMDO Treatment 6 Conclusion References Part V: Mandibular Excess - Surgical Technique - BSSO 26: Indications for Mandibular Setback 1 Conclusion References 27: Sagittal Split and Mandibular Setback 1 Mandibular Setback: BSSO 2 Conclusions References 28: Special Surgical Aspects in Mandibular Setback 1 Conclusions 29: Mandibular Excess – Modifications and Surgical Alternatives 1 Conclusion References Part VI: Asymmetries, Vertical and Horizontal Rotation, Mandibular Flaring - Surgical Techniques 30: Introduction - Asymmetries, Vertical and Horizontal Rotation, Mandibular Flaring - Surgical Techniques 1 Conclusion References 31: Diagnosis in Mandibular Asymmetries, Vertical and Horizontal Rotation 1 Photographic and Clinical Analysis 2 The Further Clinical Analysis Must Comprise 3 Radiological Diagnosis 4 The Further Radiological Analysis Must Comprise 5 Conclusion References 32: Surgical Correction in Mandibular Asymmetry 1 Chin osteotomies and Corrections of the Mandibular Rim 2 Osteotomies in the Mandibular Angle 3 Unilateral Sagittal Split Osteotomies—USSO 4 Mandibular Asymmetry in Prognathism 5 Mandibular Asymmetry in orthognathism 6 Bilateral Sagittal Split Osteotomies—BSSO 7 Rotation and Side Shift of the TMJ 8 Flaring 9 Osteotomies in the Ascending Ramus—IVRO 9.1 Surgical Technique 10 Postoperative Management 11 Which Criteria Are Decisive in the Choice of Surgical Technique? 12 Conclusion References Part VII: Mandibular Excess: class III Setback/Surgical Technique-IVRO 33: Indications for Mandibular Setback/Advancement Using IVRO or Inverted L Osteotomy 1 Conclusion References 34: Vertical Ramus Osteotomy and Mandibular Setback 1 Conclusion References 35: The Inverted L Osteotomy 1 Advantages 2 Disadvantages 3 Conclusion References Part VIII: Alveolar Segment Osteotomies 36: Types of Segmental Alveolar Osteotomies in the Mandible 1 Anterior Subapical Segmental Osteotomy 2 Posterior Subapical Osteotomy 3 Variants of an Anterior Segment Osteotomy 4 Conclusion References 37: Indications for Segmental Osteotomies in the Mandible 1 Anterior Subapical Osteotomy 2 Conclusion References 38: Preoperative Planning and Preparation for Surgery in Segmental Mandibular Osteotomies 1 Preparation for Operation 2 Profile Changes 3 Conclusion References 39: Anatomical, Surgical, and Technical Aspects 1 Decisive Anatomical Reference Points 1.1 Reference Points 1.1.1 For the Mucosal Incision 1.1.2 For Access to the Osteotomy 1.1.3 For Vertical or Horizontal Ostectomy 1.2 Surgical Aspects 1.3 Technical Aspects 1.3.1 Rotating Instruments: Burrs 1.3.2 Piezo-Surgery 1.3.3 Segment Fixation 2 Surgical Approach: Detailed Surgical Steps 2.1 Anterior Segment Osteotomy 2.2 Detailed Surgical Steps 2.2.1 Step 1: Intraoral Mucosal Incision 2.2.2 Step 2: Segment Osteotomy 2.2.3 Step 3: Segment Mobilization 2.2.4 Step 4: Setting the Segment and Intraoral Fixation 2.2.5 Step 5: Wound Closure 2.3 Technical Variants 2.3.1 Downward and Posterior Movement 2.3.2 Vertical Segment Movement 2.3.3 Upward Movement 2.3.4 Forward Movement 2.3.5 Optional Variants and Combinations 3 Conclusion References 40: Lateral Mandibular Step Osteotomy/Ostectomy, Posterior Subapical Osteotomy and Anterior Body Osteotomy 1 Lateral Mandibular Step Osteotomy/Ostectomy 1.1 Detailed Surgical Steps 1.1.1 Step 1: Mucoperiosteal Incision 1.1.2 Step 2: Osteotomy (Fig. 40.1) 1.1.3 Step 3: Setting the Segment and Fixation (Fig. 40.1) 2 Posterior Subapical Osteotomy 2.1 Indications 2.2 Detailed Surgical Steps 2.2.1 Step 1: Mucoperiosteal Incision 2.2.2 Step 2: Osteotomy 2.2.3 Step 3: Stabilization 3 Anterior Body Osteotomy (Straight Vertical Osteotomy) 3.1 Detailed Surgical Steps 3.1.1 Step 1 3.1.2 Step 2 3.1.3 Step 3 3.1.4 Step 4 3.1.5 Step 5 3.1.6 Step 6 3.1.7 Step 7 4 Conclusion References 41: Intraoperative Risks in Segment Osteotomies: Danger Points and Errors 1 Vascularization of the Segment 2 Injury of the Mental Nerve 3 Injuries to Teeth, Periodontium, and Alveolar Ridge 4 Injury of Adjacent Tooth Roots 5 Injuries Due to Osteosynthesis Screws 6 Injury of Periodontium and Alveolar Crest 6.1 Thermal Damage 6.2 Insufficient Wound Closure with Dehiscence 6.3 Insufficient Segment Stabilization 7 Conclusion References 42: Tricks and Typical Mistakes 1 Intraoperative Tricks 2 Intraoperative Errors 3 Management After Surgery 4 Limitations and Contraindications 5 Conclusion References Part IX: Chin Osteotomies 43: Indications for Chin Osteotomy/Genioplasty and Standard Procedures 1 Standard Procedures in Genioplasty 1.1 Horizontal Osteotomy for Chin Advancement 1.2 Horizontal Osteotomy for Chin Repositioning 1.3 Horizontal Sliding Osteotomy 1.4 Double Sliding Chin Osteotomy to Reduce Chin Height 1.5 Slanted Osteotomy for Chin Advancement 1.6 Transverse Narrowing/Widening Genioplasty 2 Genioplasty and Facial Profile Changes 3 Preoperative Planning 4 Conclusion References 44: Principle Surgical Technique 1 Anatomical Reference Points 2 Technical Notes 3 Horizontal Chin Osteotomy 3.1 Stepwise Surgical Approach 3.2 Fixation Technique 4 Chin Wing Osteotomy 4.1 Surgical Principle 4.2 Stepwise Surgical Approach 5 Conclusion References 45: Intraoperative Risks: Danger Points—Postoperative Complications 1 Nerve Injuries 2 Intraoperative Tricks 3 Postoperative Complications 3.1 Early Postoperative Complications 3.2 Late Complications 4 Conclusion References Part X: The Temporomandibular Joint 46: Introduction 1 Definition of TMD 2 Conclusion References 47: Diagnosis and Classification 1 Diagnosis and Classification 2 Conclusion References 48: Clinical Assessment 1 Imaging 2 Conclusion Reference 49: Management Strategies 1 TMJ Disease Prior to Commencement of Orthognathic Surgery 2 At-Risk Groups 3 Orthognathic Surgery Effects on TMD 4 TMD in the Postoperative Patient 5 Conclusion References 50: Controversy 1 Occlusion, Orthodontics, and TMD 2 Orthognathic surgery as a Treatment of TMD 3 Conclusions References Index