Adrian Becker - Orthodontic Treatment of Impacted Teeth

1 Cover

2 Dedication Page To my wife Sheila, to our children, to our grand and great grandchildren and to the memories of our parents and my sister.

3 Title Page

4 Copyright Page

5 List of Contributors

6 Preface to the First Edition

7 Preface to the Second Edition

8 Preface to the Third Edition

9 Preface to the Fourth Edition

10 About the Companion Website

11 1 General Principles Related to the Diagnosis and Treatment of Impacted Teeth Dental age Assessing dental age in the clinical setting – the Jerusalem method When is a tooth considered to be impacted? Impacted teeth and local space loss Whose problem? The timing of the surgical intervention Patient motivation and the orthodontic option References

12 2 The Logistics of Orthodontic Treatment for Impacted Teeth The anchor unit Attachments Intermediaries/connectors Elastic ties and modules versus auxiliary springs Temporary anchorage devices Magnets References

13 3 Biomechanics for Aligning Ectopic Teeth Basic principles Statically determinate and statically indeterminate systems Consistent and inconsistent systems Appliances Useful adjuncts Appendix: Colour code convention for moments and forces References

14 4 Diagnostic Imaging for Impacted Teeth Planar radiography Computerized tomography Cone beam computerized tomography References

15 5 Surgical Exposure of Impacted Teeth A brief history of surgery in relation to the treatment of impacted teeth Aims of surgery for impacted teeth Surgical intervention without orthodontic treatment The surgical elimination of pathology The principles of the surgical exposure of impacted teeth Partial and full‐flap closure on the palatal side A conservative attitude to the dental follicle Pathological pressure necrosis Quality‐of‐life issues following surgical exposure Cooperation between surgeon and orthodontist The team approach to attachment bonding References

16 6 Impacted Maxillary Central Incisors Aetiology Attitudes to treatment of obstructed central incisors Phase 1 treatment considerations Traumatic causes References

17 7 Palatally Impacted Canines Prevalence Aetiology: Local causes of palatal displacement Normal development of the maxillary anterior teeth The guidance theory of impaction The genetic theory of impaction Complications of the untreated impacted canine Diagnosis Treatment timing Prevention and interception Mechano‐therapy The need for a practical classification of palatally impacted canines The Jerusalem classification References

18 8 Buccally Impacted Maxillary Canines Canines impacted in the line of the arch Buccally displaced maxillary canines Palatally impacted labial canines The ‘window of opportunity’ Buccally impacted canines with distal displacement References

19 9 Resorption of the Roots of Neighbouring Teeth Impaction and the transition from deciduous to permanent dentition Can resorption be equated with dental caries? Prevalence of resorption Aetiology, diagnosis and prevention Treatment Exposing the impacted tooth without devitalizing the adjacent tooth Can the resorbed tooth be moved without causing further resorption? Severe incisor root resorption References

20 10 Resorption of the Impacted Tooth Invasive cervical root resorption Pre‐eruptive intra‐coronal resorption Age‐related replacement resorption References

21 11 Impacted Permanent Molars Maxillary first permanent molars Mandibular first permanent molars Mandibular second permanent molars Maxillary second molars Maxillary ‘banana’ third molars and second molar impaction Mandibular third molars Infra‐occlusion of permanent teeth Primary failure of eruption References

22 12 Premolars and Mandibular Canines Mandibular canines Mandibular second premolars Maxillary second premolars Infra‐occlusion of deciduous teeth and its influence on premolar successors Infra‐occluded teeth cause arrest of vertical bone growth References

23 13 The Root Form of Impacted Teeth Normal root development The aetiology of hooked root apices The ‘hooked root’ theory of tooth impaction Abnormal root form Fake causes References

24 14 Rescuing Teeth Impacted in Dentigerous Cysts Dentigerous cysts Radicular cysts Treatment principles The prognosis of teeth that have been severely displaced by cysts Eyelets or brackets? Conclusions References

25 15 Impacted Teeth in the Adult Patient Neglect and disguise What does the literature say? The impacted maxillary central incisor Maximizing the anchor unit with fewer teeth Implant anchorage References

26 16 Lingual Appliances, Implants and Impacted Teeth The context of impacted canines vis‐à‐vis the lingual appliance Differences in treatment approach engendered by the use of lingual appliances Canine traction, eruption and alignment Finishing procedures Anchorage considerations Integrating implants with lingual appliances Conclusion References

27 17 Clear Aligners in the Treatment of Impacted Teeth The beginning of an era Mechanical principles of the aligner Digital planning software Managing impacted teeth with clear aligners Methods of regaining space with clear aligners Impacted tooth traction while using clear aligners Clear aligner intra‐oral elastics interface References

28 18 The Anatomy of Failure Why is it important to know the cause of the failure of the tooth or teeth to erupt? Patient‐dependent factors Radiologist‐dependent factors Orthodontist‐dependent factors Surgeon‐dependent factors Mid‐treatment alternate consultations – second opinions References

29 19 Traumatic Impaction Acute traumatic intrusion (intrusive luxation) Spontaneous re‐eruption Manipulative/surgical repositioning and splinting Orthodontic reduction Orthodontic treatment considerations Indications for the different types of orthodontic appliance Conclusion References

30 20 Extreme Impactions, Unusual Phenomena, Difficult Decisions Case 20.1: Monster tooth, supernumerary tooth, impacted central incisor and the maxillary midline Case 20.2: Bilaterally impacted maxillary canines in a patient suffering with aggressive juvenile periodontitis Case 20.3: Labially impacted maxillary canine at the level of the nasal floor Case 20.4: The inaccessible canine Case 20.5: Severe trauma in infancy: repairing the damage with orthodontics Case 20.6: Labial to the lateral incisor and lingual to the central incisor Case 20.7: Three adjacent impacted molars Case 20.8: Five unerupted teeth in the walls of a dentigerous cyst References

31 21 Cleidocranial Dysplasia Clinical features and dental characteristics Diagnosis Treatment modalities Recognition of the clinical features What about the skeletal class III relationship in cleidocranial dysplasia patients? What management protocol can be used to achieve this level of compliance? Erupting the permanent teeth Surgical therapeutic measures Orthodontic strategy Preparing the patient The Jerusalem approach in clinical practice Extreme tooth movement Retention of the treated result Orthognathic surgery References

32 Index

33 End User License Agreement

1 Chapter 1 Table 1.1 Apexification age of individual tooth types.

2 Chapter 3 Table 3.1 Colour code convention.

3 Chapter 4 Table 4.1 Typical effective dose from radiographic examination.

4 Chapter 5 Table 5.1 Immediate effects of closed and open exposure treatments on quali... Table 5.2 An instrument tray for a team approach.

1 Chapter 1 Fig. 1.1 The advanced root development of the canines and premolars indicate... Fig. 1.2 A 12‐year‐old patient with root development indicating the late den... Fig. 1.3 The mandibular left second deciduous molar is retained (extraction ... Fig. 1.4 Root apices are closed in all first molars, all mandibular and thre... Fig. 1.5 No closed apices. Dental age assessment 7–7.5 years. Fig. 1.6 Late‐developing second mandibular premolars with retained ( not over... Fig. 1.7 The left mandibular premolars are prematurely erupted, with insuffi... Fig. 1.8 Space loss in a 10‐year‐old child, due to an impacted maxillary rig... Fig. 1.9 (a) Chance finding of mesiodens in a 4‐year‐old child. (b) Chance f... Fig. 1.10 An 8‐year‐old child exhibits an unerupted maxillary left central i...